Inés Díaz‐Laviada

Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. When these tumors are in advanced stages, few therapeutic options are available. Therefore, it is essential to search for new treatments to fight this disease. In this study, we investigated the effects of cannabinoids--a novel family of potential anticancer agents--on the growth of HCC. We found that Δ(9)-tetrahydrocannabinol (Δ(9)-THC, the main active component of Cannabis sativa) and JWH-015 (a cannabinoid receptor 2 (CB(2)) cannabinoid receptor-selective agonist) reduced the viability of the human HCC cell lines HepG2 (human hepatocellular liver carcinoma cell line) and HuH-7 (hepatocellular carcinoma cells), an effect that relied on the stimulation of CB(2) receptor. We also found that Δ(9)-THC- and JWH-015-induced autophagy relies on tribbles homolog 3 (TRB3) upregulation, and subsequent inhibition of the serine-threonine kinase Akt/mammalian target of rapamycin C1 axis and adenosine monophosphate-activated kinase (AMPK) stimulation. Pharmacological and genetic inhibition of AMPK upstream kinases supported that calmodulin-activated kinase kinase β was responsible for cannabinoid-induced AMPK activation and autophagy. In vivo studies revealed that Δ(9)-THC and JWH-015 reduced the growth of HCC subcutaneous xenografts, an effect that was not evident when autophagy was genetically of pharmacologically inhibited in those tumors. Moreover, cannabinoids were also able to inhibit tumor growth and ascites in an orthotopic model of HCC xenograft. Our findings may contribute to the design of new therapeutic strategies for the management of HCC.

Recent evidence suggests the involvement of phosphatidylcholine (PC) hydrolysis both in the control of normal cell growth and in transformation. We show here that the simple exogenous addition of Bacillus cereus PC-hydrolyzing phospholipase C (PC-PLC) is sufficient to elicit a potent mitogenic response in Swiss 3T3 fibroblasts by a mechanism that is independent of protein kinase C. Our results on the additivity and synergism between B. cereus PC-PLC, PDGF, and insulin in the mitogenic response indicate that this novel phospholipid degradative pathway may be important in the mitogenic signaling cascade activated by PDGF.

Cannabinoids exert antiproliferative effects in a wide range of tumoral cells, including hepatocellular carcinoma (HCC) cells. In this study, we examined whether the PPARγ-activated pathway contributed to the antitumor effect of two cannabinoids, Δ9-tetrahydrocannabinol (THC) and JWH-015, against HepG2 and HUH-7 HCC cells. Both cannabinoids increased the activity and intracellular level of PPARγ mRNA and protein, which was abolished by the PPARγ inhibitor GW9662. Moreover, genetic ablation with small interfering RNA (siRNA), as well as pharmacological inhibition of PPARγ decreased the cannabinoid-induced cell death and apoptosis. Likewise, GW9662 totally blocked the antitumoral action of cannabinoids in xenograft-induced HCC tumors in mice. In addition, PPARγ knockdown with siRNA caused accumulation of the autophagy markers LC3-II and p62, suggesting that PPARγ is necessary for the autophagy flux promoted by cannabinoids. Interestingly, downregulation of the endoplasmic reticulum stress-related protein tribbles homolog 3 (TRIB3) markedly reduced PPARγ expression and induced p62 accumulation, which was counteracted by overexpression of PPARγ in TRIB3-knocked down cells. Taken together, we demonstrate for the first time that the antiproliferative action of the cannabinoids THC and JWH-015 on HCC, in vitro and in vivo, are modulated by upregulation of PPARγ-dependent pathways.

Current chemotherapy for castration-resistant prostate cancer is established on taxane-based compounds like docetaxel. However, eventually, the development of toxic side effects and resistance limits the therapeutic benefit being the major concern in the treatment of prostate cancer. Combination therapies in many cases, enhance drug efficacy and delay the appearance of undesired effects, representing an important option for the treatment of castration-resistant prostate cancer. In this study, we tested the efficacy of the combination of docetaxel and capsaicin, the pungent ingredient of hot chili peppers, on prostate cancer cells proliferation. Prostate cancer LNCaP and PC3 cell lines were used in this study. Levels of total and phosphorylated forms of Akt, mTOR, S6, LKB1, AMPK and ACC were determined by Western blot. AMPK, LKB1 and Akt knock down was performed by siRNA. PTEN was overexpressed by transient transfection with plasmids. Xenograft prostate tumors were induced in nude mice and treatments (docetaxel and capsaicin) were administered intraperitoneally. Statistical analyses were performed with GraphPad software. Combination index was calculated with Compusyn software. Docetaxel and capsaicin synergistically inhibited the growth of LNCaP and PC3 cells, with a combination index lower than 1 for most of the combinations tested. Co-treatment with docetaxel and capsaicin notably decreased Akt and its downstream targets mTOR and S6 phosphorylation. Overexpression of PTEN phosphatase abrogated the synergistic antiproliferative effect of docetaxel and capsaicin. The combined treatment also increased the phosphorylation of AMP-activated kinase (AMPK) and the phosphorylation of its substrate ACC. In addition, pharmacological inhibition of AMPK with dorsomorphin (compound C) as well as knock down by siRNA of AMPK or its upstream kinase LKB1, abolished the synergy of docetaxel and capsaicin. Mechanistically, we showed that the synergistic anti-proliferative effect may be attributed to two independent effects: Inhibition of the PI3K/Akt/mTOR signaling pathway by one side, and AMPK activation by the other. In vivo experiments confirmed the synergistic effects of docetaxel and capsaicin in reducing the tumor growth of PC3 cells. Combination of docetaxel and capsaicin represents a therapeutically relevant approach for the treatment of Prostate Cancer.

The effect of Δ 9 ‐tetrahydrocannabinol (THC), the major psycho‐active component of marijuana, in human prostate cancer cells PC‐3 was investigated. THC caused apoptosis in a dose‐dependent manner. Morphological and biochemical changes induced by THC in prostate PC‐3 cells shared the characteristics of an apoptotic phenomenon. First, loss of plasma membrane asymmetry determined by fluorescent anexin V binding. Second, presence of apoptotic bodies and nuclear fragmentation observed by DNA staining with 4′,6‐diamino‐2‐phenylindole (DAPI). Third, presence of typical ‘ladder‐patterned’ DNA fragmentation. Central cannabinoid receptor expression was observed in PC‐3 cells by immunofluorescence studies. However, several results indicated that the apoptotic effect was cannabinoid receptor‐independent, such as lack of an effect of the potent cannabinoid agonist WIN 55,212‐2, inability of cannabinoid antagonist AM 251 to prevent cellular death caused by THC and absence of an effect of pertussis toxin pre‐treatment.

Vanilloid receptor subtype-1 (TRPV1), the founding member of the vanilloid receptor-like transient receptor potential channel family, is a non-selective cation channel that responds to noxious stimuli such as low pH, painful heat and irritants. In the present study, we show, as means of reverse transcriptase-polymerase chain reaction and Western blot analysis, that the vanilloid TRPV1 receptor is expressed in the prostate epithelial cell lines PC-3 and LNCaP as well as in human prostate tissue. The kinetic parameters inferred from [125I]-resiniferatoxin binding were in concordance with data of TRPV1 receptors expressed in other tissues. The contribution of the endogenously expressed TRPV1 channel to intracellular calcium concentration increase in the prostate cells was studied by measuring changes in Fura-2 fluorescence by fluorescence microscopy. Addition of capsaicin, (R)-methanandamide and resiniferatoxin to prostate cells induced a dose-dependent increase in the intracellular calcium concentration that was reversed by the vanilloid TRPV1 receptor antagonist capsazepine. These results indicate that the vanilloid TRPV1 receptor is expressed and functionally active in human prostate cells.

The products of ras and src oncogenes are thought to be important components in pathways regulating cell proliferation and differentiation. In fibroblasts transformed by these oncogenes, increased diacylglycerol levels have been found which most probably arise from activation of the turnover of phosphatidylcholine. Diacylglycerol is a key activator of protein kinase C whose role in cell growth and transformation has been proposed. We demonstrate here by using immunochemical techniques that transformation by ras or src oncogenes is associated with permanent translocation of protein kinase C to the cytoplasmic membrane. However, no down-regulation of the enzyme is observed despite its permanent activation in these transformants. Importantly, the lack of down-regulation observed in ras and src transformed cell lines is mimicked by chronic treatment of NIH 3T3 fibroblasts with exogenous Bacillus cereus phosphatidylcholine-hydrolysing phospholipase C, but not with phorbol myristate acetate or exogenous Bacillus thuringiensis phosphatidylinositol-hydrolysing phospholipase C. These results strongly suggest that diacylglycerol derived from phosphatidylcholine but not from phosphoinositide turnover is responsible for the atypical regulation of protein kinase C in cell lines transformed by ras and src oncogenes.

We have previously shown that cannabinoids induce growth inhibition and apoptosis in prostate cancer PC-3 cells, which express high levels of cannabinoid receptor types 1 and 2 (CB(1) and CB(2)). In this study, we investigated the role of CB(2) receptor in the anti-proliferative action of cannabinoids and the signal transduction triggered by receptor ligation.The human prostate cancer cell lines, namely PC-3, DU-145 and LNCaP, were used for this study. Cell proliferation was measured using MTT proliferation assay, [(3)H]-thymidine incorporation assay and cell-cycle study by flow cytometry. Ceramide quantification was performed using the DAG kinase method. The CB(2) receptor was silenced with specific small interfering RNA, and was blocked pharmacologically with SR 144528. In vivo studies were conducted by the induction of prostate xenograft tumours in nude mice.We found that the anandamide analogue, R(+)-Methanandamide (MET), as well as JWH-015, a synthetic CB(2) agonist, exerted anti-proliferative effects in PC-3 cells. R(+)-Methanandamide- and JWH-015-induced cell death was rescued by treatment with the CB(2) receptor antagonist, SR 144528. Downregulation of CB(2) expression reversed the effects of JWH-015, confirming the involvement of CB(2) in the pro-apoptotic effect of cannabinoids. Further analysing the mechanism of JWH-015-induced cell growth inhibition, we found that JWH-015 triggered a de novo synthesis of ceramide, which was involved in cannabinoid-induced cell death, insofar as blocking ceramide synthesis with Fumonisin B1 reduced cell death. Signalling pathways activated by JWH-015 included JNK (c-Jun N-terminal kinase) activation and Akt inhibition. In vivo treatment with JWH-015 caused a significant reduction in tumour growth in mice.This study defines the involvement of CB(2)-mediated signalling in the in vivo and in vitro growth inhibition of prostate cancer cells and suggests that CB(2) agonists have potential therapeutic interest and deserve to be explored in the management of prostate cancer.

Capsaicin, one of the major pungent ingredients found in red peppers, has been recently demonstrated to induce apoptosis in many types of malignant cell lines including colon adenocarcinoma, pancreatic cancer, hepatocellular carcinoma, prostate cancer, breast cancer, and many others. The mechanism whereby capsaicin induces apoptosis in cancer cells is not completely elucidated but involves intracellular calcium increase, reactive oxygen species generation, disruption of mitochondrial membrane transition potential, and activation of transcription factors such as NFκB and STATS. Recently, a role for the AMP-dependent kinase (AMPK) and autophagy pathways in capsaicin-triggered cell death has been proposed. In addition, capsaicin shows antitumor activity in vivo by reducing the growth of many tumors induced in mice. In this chapter, we report the last advances performed in the antitumor activity of capsaicin and review the main signaling pathways involved.

// Ágata Ramos-Torres 1 , Alicia Bort 1 , Cecilia Morell 1 , Nieves Rodríguez-Henche 1 , Inés Díaz-Laviada 1 1 Department of System Biology, Biochemistry and Molecular Biology Unit, School of Medicine, Alcala University, Alcala de Henares 28871, Madrid, Spain Correspondence to: Ines Diaz-Laviada, e-mail: ines.diazlaviada@uah.es Keywords: capsaicin, reactive oxygen species, autophagy, prostate cancer Received: August 04, 2015 Accepted: November 16, 2015 Published: November 27, 2015 ABSTRACT Capsaicin, the pungent ingredient of red hot chili peepers, has been shown to have anti-cancer activities in several cancer cells, including prostate cancer. Several molecular mechanisms have been proposed on its chemopreventive action, including ceramide accumulation, endoplasmic reticulum stress induction and NFκB inhibition. However, the precise mechanisms by which capsaicin exerts its anti-proliferative effect in prostate cancer cells remain questionable. Herein, we have tested the involvement of autophagy on the capsaicin mechanism of action on prostate cancer LNCaP and PC-3 cells. The results showed that capsaicin induced prostate cancer cell death in a time- and concentration-dependent manner, increased the levels of microtubule-associated protein light chain 3-II (LC3-II, a marker of autophagy) and the accumulation of the cargo protein p62 suggesting an autophagy blockage. Moreover, confocal microscopy revealed that capsaicin treatment increased lysosomes which co-localized with LC3 positive vesicles in a similar extent to that produced by the lysosomal protease inhibitors E64 and pepstatin pointing to an autophagolysosomes breakdown inhibition. Furthermore, we found that capsaicin triggered ROS generation in cells, while the levels of ROS decreased with N-acetyl-cysteine (NAC), a ROS scavenger. Co-treatment of cells with NAC and capsaicin abrogated the effects of capsaicin on autophagy and cell death. Normal prostate PNT2 and RWPE-1 cells were more resistant to capsaicin-induced cytotoxicity and did not accumulate p62 protein. Taken together, these results suggest that ROS-mediated capsaicin-induced autophagy blockage contributes to antiproliferation in prostate cancer cells, which provides new insights into the anticancer molecular mechanism of capsaicin.

Obesity, a major risk factor for chronic diseases such as type 2 diabetes (T2D), represents a serious primary health problem worldwide. Dietary habits are of special interest to prevent and counteract the obesity and its associated metabolic disorders, including lipid steatosis. Capsaicin, a pungent compound of chili peppers, has been found to ameliorate diet-induced obesity in rodents and humans. The purpose of this study was to examine the effect of capsaicin on hepatic lipogenesis and to delineate the underlying signaling pathways involved, using HepG2 cells as an experimental model. Cellular neutral lipids, stained with BODIPY493/503, were quantified by flow cytometry, and the protein expression and activity were determined by immunoblotting. Capsaicin reduced basal neutral lipid content in HepG2 cells, as well that induced by troglitazone or by oleic acid. This effect of capsaicin was prevented by dorsomorphin and GW9662, pharmacological inhibitors of AMPK and PPARγ, respectively. In addition, capsaicin activated AMPK and inhibited the AKT/mTOR pathway, major regulators of hepatic lipogenesis. Furthermore, capsaicin blocked autophagy and increased PGC-1α protein. These results suggest that capsaicin behaves as an anti-lipogenic compound in HepG2 cells.

DPP4/CD26 is a single-pass transmembrane protein with multiple functions on glycemic control, cell migration and proliferation, and the immune system, among others. It has recently acquired an especial relevance due to the possibility to act as a receptor or co-receptor for SARS-CoV-2, as it has been already demonstrated for other coronaviruses. In this review, we analyze the evidence for the role of DPP4 on COVID-19 risk and clinical outcome, and its contribution to COVID-19 physiopathology. Due to the pathogenetic links between COVID-19 and diabetes mellitus and the hyperinflammatory response, with the hallmark cytokine storm developed very often during the disease, we dive deep into the functions of DPP4 on carbohydrate metabolism and immune system regulation. We show that the broad spectrum of functions regulated by DPP4 is performed both as a protease enzyme, as well as an interacting partner of other molecules on the cell surface. In addition, we provide an update of the DPP4 inhibitors approved by the EMA and/or the FDA, together with the newfangled approval of generic drugs (in 2021 and 2022). This review will also cover the effects of DPP4 inhibitors (i.e., gliptins) on the progression of SARS-CoV-2 infection, showing the role of DPP4 in this disturbing disease.

In this study, capsaicin ( trans ‐8‐methyl‐ N ‐vanillyl‐6‐nonenamide) induced an increase in the cell viability of the androgen‐responsive prostate cancer LNCaP cells, which was reversed by the use of the TRPV1 antagonists capsazepine, I‐RTX and SB 366791. In further studies we observed that capsaicin induced a decrease in ceramide levels as well as Akt and Erk activation. To investigate the mechanism of capsaicin action we measured androgen (AR) receptor levels. Capsaicin induced an increase in the AR expression that was reverted by the three TRPV1 antagonists. AR silencing by the use of siRNA, as well as blocking the AR receptor with bicalutamide, inhibited the proliferative effect of capsaicin.

During the past decades, intense attention has been focused on the anti-tumor properties of marine compounds which some of them have been revealed as potent apoptotic inducers. In the present work, we studied the mechanism of action of a new compound, Spisulosine (ES-285), isolated from the sea mollusc Spisula polynyma, in the prostate tumor PC-3 and LNCaP cell lines. Spisulosine inhibited cell proliferation with an IC50 of 1 microM in both cell lines, although it was more effective in the androgen-independent PC-3 cells. The anti-proliferative effect induced by Spisulosine in prostate cells was independent of peroxisome proliferator activated receptor gamma (PPARgamma) and phosphatidylinositol 3-kinase/(PI3K/Akt), Jun N-terminal kinase (JNK), p38 or classical protein kinase C (PKCs) pathways, as it was inferred from the results obtained with specific inhibitors of these routes. However, Spisulosine treatment of prostate cells induced an increase in the intracellular ceramide levels, that was totally blocked by the ceramide synthase inhibitor Fumonisin B1, indicating that the ceramide accumulation came from the de novo biosynthesis. Spisulosine also induced in both PC-3 and LNCaP cells, an activation of the atypical PKC isoform, PKCzeta, which is one of the target proteins of ceramide. These results indicate that the marine compound Spisulosine inhibits the growth of the prostate PC-3 and LNCaP cells through intracellular ceramide accumulation and PKCzeta activation.

The effect of capsaicin, main pungent ingredient of hot chilli peppers, in the gene expression profile of human prostate PC-3 cancer cells has been analyzed using a microarray approach. We identified 10 genes that were down-regulated and five genes that were induced upon capsaicin treatment. The data obtained from microarray analysis were then validated using quantitative real-time PCR assays and Western blot analysis. The most remarkable change was the up-regulation of GADD153/CHOP, an endoplasmic reticulum stress-regulated gene. Activation of GADD153/CHOP protein was corroborated by immunofluorescence and Western blot. We then tested the contribution of GADD153/CHOP to protection against capsaicin-induced cell death using RNA interference. Blockage of GADD153/CHOP expression by small interfering RNA, significantly reduced capsaicin-induced cell death in PC-3 cells. Taken together, these results suggested that capsaicin induces the antiproliferative effect through a mechanism facilitated by ER stress in prostate PC-3 cells.

Capsaicin (CAP) has been long known for its analgesic properties and more recently for its antitumor activity in various cell types. However, its pungency and the high doses needed to achieve a significant activity have precluded its application in cancer therapy. Herein, we propose a straightforward novel strategy to improve the antitumor effect of CAP based on the enhancement of its aggregation propensity in aqueous media by covalent attachment of a BODIPY (BDP) dye. The target CAP-BDP 1 self-assembles in aqueous solutions into weakly fluorescent globular assemblies that become highly emissive upon cell uptake-induced disassembly. Remarkably, due to the improved delivery to the tumour tissue upon aggregation, we have succeeded in reducing the doses of CAP-based drugs in vivo in prostate cancer by two orders of magnitude while maintaining a substantial antitumor activity.

In the past few years, cell plasticity has emerged as a mode of targeted therapy evasion in prostate adenocarcinoma. When exposed to anticancer therapies, tumor cells may switch into a different histological subtype, such as the neuroendocrine phenotype which is associated with treatment failure and a poor prognosis. In this study, we demonstrated that long-term androgen signal depletion of prostate LNCaP cells induced a neuroendocrine phenotype followed by re-differentiation towards a “stem-like” state. LNCaP cells incubated for 30 days in charcoal-stripped medium or with the androgen receptor antagonist 2-hydroxyflutamide developed neuroendocrine morphology and increased the expression of the neuroendocrine markers βIII-tubulin and neuron specific enolase (NSE). When cells were incubated for 90 days in androgen-depleted medium, they grew as floating spheres and had enhanced expression of the stem cell markers CD133, ALDH1A1, and the transporter ABCB1A. Additionally, the pluripotent transcription factors Nanog and Oct4 and the angiogenic factor VEGF were up-regulated while the expression of E-cadherin was inhibited. Cell viability revealed that those cells were resistant to docetaxel and 2-hidroxyflutamide. Mechanistically, androgen depletion induced the decrease in AMP-activated kinase (AMPK) expression and activation and stabilization of the hypoxia-inducible factor HIF-1α. Overexpression of AMPK in the stem-like cells decreased the expression of stem markers as well as that of HIF-1α and VEGF while it restored the levels of E-cadherin and PGC-1α. Most importantly, docetaxel sensitivity was restored in stem-like AMPK-transfected cells. Our model provides a new regulatory mechanism of prostate cancer plasticity through AMPK that is worth exploring.

In recent years, natural products have emerged as modulators of many cellular responses, with potential applications as therapeutic drugs in many disorders. Among them, capsaicin, the pungent agent in chili peppers, has been demonstrated to have a role as a tumor suppressor for prostate cancer. Capsaicin potently suppresses the growth of human prostate carcinoma cells in vitro and in vivo. The antiproliferative activity of capsaicin correlates with oxidative stress induction and apoptosis. Capsaicin also induces ceramide accumulation and endoplasmic reticulum stress in androgen-resistant prostate cells. In androgen-sensitive prostate cancer cells, capsaicin exerts a biphasic effect, promoting growth at low doses and inducing apoptosis at doses over 200 µM. This article will draw upon multiple lines of evidence to provide a comprehensive description on the current state of knowledge that implicates the effect of capsaicin on prostate cancer cells.

Capsaicin (8-methyl-N-vanillyl-6-nonenamide), a constituent of green and red peppers, has been linked with suppression of tumorigenesis through a mechanism that is not well understood. In the present study, we examined the effects of capsaicin on the production of the cytokine interleukin (IL)-6 by PC-3 cells at both protein and mRNA levels which were evaluated by ELISA and real-time PCR, respectively. Capsaicin-treated PC-3 cells increased the synthesis and secretion of IL-6 which was abrogated by the transient receptor potential vanilloid receptor subtype 1 (TRPV1) antagonist capsazepine, as well as by inhibitors of PKC-α, phosphoinositol-3 phosphate kinase (PI-3K), Akt and extracellular signal-regulated protein kinase (ERK). We analyzed the role of capsaicin in the tumor necrosis factor (TNF)-α secretion by PC-3 cells which was increased at shorter times than IL-6 production. Furthermore, incubation of PC-3 cells with an anti-TNF-α antibody blocked the capsaicin-induced IL-6 secretion. These results raise the possibility that capsaicin-mediated IL-6 increase in prostate cancer PC-3 cells is regulated at least in part by TNF-α secretion and signaling pathway involving Akt, ERK and PKC-α activation.

Chromenopyrazolediones have been designed and synthesized as anticancer agents using the multi-biological target concept that involves quinone cytotoxicity and cannabinoid antitumor properties. In cell cytotoxicity assays, these chromenopyrazolediones have antiproliferative activity against human prostate cancer and hepatocellular carcinoma. It has been shown that the most potent, derivative 4 (PM49), inhibits prostate LNCaP cell viability (IC50 = 15 μM) through a mechanism involving oxidative stress, PPARγ receptor and partially CB1 receptor. It acts on prostate cell growth by causing G0/G1 phase arrest and triggering apoptosis as assessed by flow cytometry measurements. In the in vivo treatment, compound 4 at 2 mg/kg, blocks the growth of LNCaP tumors and reduces the growth of PC-3 tumors generated in mice. These studies suggest that 4 is a good potential anticancer agent against hormone-sensitive prostate cancer.

Neuroendocrine (NE) prostate cancer (PCa) is a highly aggressive subtype of prostate cancer associated with resistance to androgen ablation therapy. In this study, we used LNCaP prostate cancer cells cultured in a serum-free medium for 6 days as a NE model of prostate cancer. Serum deprivation increased the expression of NE markers such as neuron-specific enolase (NSE) and βIII tubulin (βIII tub) and decreased the expression of the androgen receptor protein in LNCaP cells. Using cDNA microarrays, we compared gene expression profiles of NE cells and non-differentiated LNCaP cells. We identified up-regulation of 155 genes, among them LAMP2, a lysosomal membrane protein involved in lysosomal stability and autophagy. We then confirmed up-regulation of LAMP2 in NE cells by qRT-PCR, Western blot and confocal microscopy assays, showing that mRNA up-regulation correlated with increased levels of LAMP2 protein. Subsequently, we determined autophagy activity in NE cells by assessing the protein levels of SQSTM/p62 and LC3 by Western blot and LC3 and Atg5 mRNAs content by qRT-PCR. The decreased levels of SQSTM/p62 was accompanied by an enhanced expression of LC3 and ATG5, suggesting activation of autophagy in NE cells. Blockage of autophagy with 1μM AKT inhibitor IV, or by silencing Beclin 1 and Atg5, prevented NE cell differentiation, as revealed by decreased levels of the NE markers. In addition, AKT inhibitor IV as well as Beclin1 and Atg5 kwockdown attenuated LAMP2 expression in NE cells. On the other hand, LAMP2 knockdown by siRNA led to a marked blockage of autophagy, prevention of NE differentiation and decrease of cell survival. Taken together, these results suggest that LAMP2 overexpression assists NE differentiation of LNCaP cells induced by serum deprivation and facilitates autophagy activity in order to attain the NE phenotype and cell survival. LAMP2 could thus be a potential biomarker and potential target for NE prostate cancer.

In this study, we investigated the antitumoral effects of combined treatment using sorafenib and capsaicin in hepatocellular carcinoma (HCC) cells. Here we showed that the combination of the two drugs had a much stronger inhibitory effect on both HepG2 and Huh-7 human HCC cells growth than either drug alone. The isobolograms demonstrated that the combinations investigated in this study produced a synergistic interaction. In the combination treatment using capsaicin and sorafenib, increased apoptosis, followed by the activation of caspase-9 and PARP, was observed. In addition, the present study demonstrated that sorafenib treatment induces activation of Akt, probably as a mechanism of resistance, whereas capsaicin inhibits Akt providing a possible pathway whereby capsaicin sensitizes to sorafenib in HCC cells. Moreover, capsaicin singly and the combination of capsaicin and sorafenib induce AMPK activation and Acetyl CoA carboxylase phosphorylation in HCC cells. Knocking down of AMPK by selective siRNA abrogates capsaicin-induced Akt inhibition, suggesting the involvement of AMPK in the antiproliferative effect. In vivo experiments further showed that that the anti-tumor effect of sorafenib was enhanced by its combination with 2.5 mg/Kg of capsaicin. Overall, these results show that combined treatment with capsaicin and sorafenib might improve sorafenib sensitivity and therefore it represents a promising and attractive strategy for the treatment of HCC.

Neuroendocrine (NE) differentiation represents a common feature of prostate cancer and is associated with accelerated disease progression and poor clinical outcome. Nowadays, there is no treatment for this aggressive form of prostate cancer. The aim of this study was to determine the influence of the cannabinoid WIN 55,212-2 (WIN, a non-selective cannabinoid CB1 and CB2 receptor agonist) on the NE differentiation of prostate cancer cells. NE differentiation of prostate cancer LNCaP cells was induced by serum deprivation or by incubation with interleukin-6, for 6 days. Levels of NE markers and signaling proteins were determined by western blotting. Levels of cannabinoid receptors were determined by quantitative PCR. The involvement of signaling cascades was investigated by pharmacological inhibition and small interfering RNA. The differentiated LNCaP cells exhibited neurite outgrowth, and increased the expression of the typical NE markers neuron-specific enolase and βIII tubulin (βIII Tub). Treatment with 3 μM WIN inhibited NK differentiation of LNCaP cells. The cannabinoid WIN downregulated the PI3K/Akt/mTOR signaling pathway, resulting in NE differentiation inhibition. In addition, an activation of AMP-activated protein kinase (AMPK) was observed in WIN-treated cells, which correlated with a decrease in the NE markers expression. Our results also show that during NE differentiation the expression of cannabinoid receptors CB1 and CB2 dramatically decreases. Taken together, we demonstrate that PI3K/Akt/AMPK might be an important axis modulating NE differentiation of prostate cancer that is blocked by the cannabinoid WIN, pointing to a therapeutic potential of cannabinoids against NE prostate cancer.

Hepatocellular carcinoma ( HCC ) is the third leading cause of cancer death worldwide. HCC treatment is hindered by the frequent emergence of chemoresistance to the multikinase inhibitor sorafenib, which has been related to the presence of cancer stem cells ( CSC s) that self‐renew and often escape therapy. The key metabolic sensor AMP ‐activated kinase ( AMPK ) has recently been recognized as a tumour growth regulator. In this study, we aimed to elucidate the role of AMPK in the development of a stem cell phenotype in HCC cells. To this end, we enriched the CSC population in HCC cell lines that showed increased expression of drug resistance ( ALDH 1A1, ABCB 1A) and stem cell ( CD 133, Nanog, Oct4, alpha fetoprotein) markers and demonstrated their stemness phenotype. These cells were refractory to sorafenib‐induced cell death. We report that sorafenib‐resistant cells had lower levels of total and phosphorylated AMPK as well as its downstream substrate, ACC , compared with the parental cells. Interestingly, AMPK knockdown with si RNA or inhibition with dorsomorphin increased the expression of stem cell markers in parental cells and blocked sorafenib‐induced cell death. Conversely, the upregulation of AMPK , either by transfection or by pharmacological activation with A‐769662, decreased the expression of ALDH 1A1, ABCB 1A, CD 133, Nanog, Oct4, and alpha fetoprotein, and restored sensitivity to sorafenib. Analysis of the underlying mechanism points to hypoxia‐inducible factor HIF ‐1α as a regulator of stemness. In vivo studies in a xenograft mouse model demonstrated that stem‐like cells have greater tumourigenic capacity. AMPK activation reduced xenograft tumour growth and decreased the expression of stem cell markers. Taken together, these results indicate that AMPK may serve as a novel target to overcome chemoresistance in HCC .

A novel phospholipase C specific for phosphatidylcholine has been shown to be activated by several agonists. Also, recent evidence suggests that transformation mediated by the ras oncogene possibly involves the activation of this novel phospholipid degradative pathway which would account for the increased diacylglycerol levels associated with transformation. Here we use a mutant of Ki-ras which is temperature-sensitive for transformation to investigate the kinetics of activation of the phosphodiesterase-mediated turnover of phosphatidylcholine. Upon shift to the permissive temperature, products of the activated phosphatidylcholine-specific phospholipase C were detected by 30 min and reached maximal levels by 1-2 h. These results suggest that the product of the ras oncogene rapidly activates the phosphodiesteratic hydrolysis of phosphatidylcholine. Furthermore, the fact that at least 4 h are required for serum to activate this phospholipase C strongly suggests that the ras oncogene product might be involved in late steps of the mitogenic signaling cascade.

It has been recently shown that cannabinoids may regulate the growth of many cell types. In the present work we examined the effect of the anandamide analogue (R)-methanandamide (MET) on androgen-dependent prostate LNCaP cell growth. We found that 0.1 microM MET had a mitogenic effect measured by [(3)H]thymidine incorporation into DNA. The effect exerted by MET was blocked by the cannabinoid receptor antagonists SR141716 (SR1) and SR144528 (SR2) as well as by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, suggesting an involvement of cannabinoid receptors and the PI3K pathway in the mechanism of MET action. MET treatment of LNCaP cells also induced an up-regulation of androgen receptor expression that was blocked by the two cannabinoid receptor antagonists SR1 and SR2. These results show for the first time that cannabinoids may modify androgen receptor expression in an androgen-dependent cell line and by this mechanism could regulate prostate cell growth.

Since the discovery that cannabinoids exert biological actions through binding to specific receptors, signal mechanisms triggered by these receptors have been focus of extensive study. This review summarizes the current knowledge of the signalling events produced by cannabinoids from membrane receptors to downstream regulators. Two types of cannabinoid receptors have been identified to date: CB1 and CB2 both belonging to the heptahelichoidal receptor family but with different tissue distribution and signalling mechanisms. Coupling to inhibitory guanine nucleotide-binding protein and thus inhibition of adenylyl cyclase has been observed in both receptors but other signal transduction pathways that are regulated or not by these G proteins are differently activated upon ligand-receptor binding including ion channels, sphingomyelin hydrolysis, ceramide generation, phospholipases activation and downstream targets as MAP kinase cascade, PI3K, FAK or NOS regulation. Cannabinoids may also act independently of CB1or CB2 receptors. The existence of new unidentified putative cannabinoid receptors has been claimed by many investigators. Endocannabinoids activate vanilloid TRPV1 receptors that may mediate some of the cannabinoid effects. Other actions of cannabinoids can occur through non-receptor-mediated mechanisms. Keywords: tetrahydrocannabinol, cannabimimetic agents, g proteins, fan protein, adenylyl cyclase, voltage-gated channels, map kinase, focal adhesion kinase (fak), phospholipase d, ceramide

The natural bioactive compound capsaicin has been reported to have anticancer activity, although the underlying mechanism of action has not been completely clarified. Herein, we investigated the mechanism whereby capsaicin exerts antitumor effects on prostate cancer cells. We found that capsaicin activated AMP-activated kinase (AMPK) and promoted cell death in the LKB1-expressing prostate cancer cell lines LNCaP and PC3, but not in the liver kinase B1 (LKB1)-null cell line DU-145. Capsaicin treatment stimulated LKB1 phosphorylation and activated AMPK in LKB1-expressing cells. In addition, LKB1 silencing in LNCaP and PC3 cells abrogated capsaicin-induced AMPK activation, while the overexpression of LKB1 by lentiviral infection in DU-145 cells induced capsaicin-triggered AMPK phosphorylation. Moreover, the calcium/calmodulin-dependent kinase kinase 2 (CaMKK2) inhibitor STO-609 did not modify the activation of AMPK induced by capsaicin, suggesting a CaMKK2-independent mechanism. Capsaicin-induced LKB1 phosphorylation was dependent on the transient receptor potential cation channel subfamily V member 1 (TRPV1), since TRPV1 knocked down by shRNA abolished LKB1 and AMPK phosphorylation in LKB1-expressing cells. Altogether, our results showed that capsaicin affected AMPK activity in an LKB1- and TRPV1-dependent fashion, linking TRPV1 with cell fate. These data also suggest that capsaicin may be a rational chemotherapeutic option for prostate tumors.

Abstract The phospholipase C-mediated hydrolysis of phosphatidylcholine has been shown recently to be activated by a number of agonists. Muscarinic receptors, which trigger various signal transduction mechanisms including inhibition of adenylate cyclase through Gi, have been shown to be potent stimulants of this novel phospholipid degradative pathway. We demonstrate here, by exogenous addition of Bacillus cereus phosphatidylcholine-hydrolyzing phospholipase C, that phosphatidylcholine breakdown mimics the ability of carbachol to inhibit adenylate cyclase. This effect is sensitive to pertussis toxin and is entirely dependent on the presence of protein kinase C. This kinase is also required for the inhibition by carbachol of adenylate cyclase. These results suggest that the activation of phosphatidylcholine breakdown by phospholipase C may play an important role linking or favoring the coupling muscarinic receptors to Gi. Results presented here also show that phospholipase C-mediated hydrolysis of phosphoinositides by exogenous addition of Bacillus thuringiensis phosphoinositide-hydrolyzing phospholipase C does not affect adenylate cyclase, despite the fact that protein kinase C is translocated to an extent similar to that produced by the hydrolysis of phosphatidylcholine. According to the results shown here, both phospholipases also differ their ability to down-regulate protein kinase C as well as to phosphorylate p80 and to transmodulate the binding of epidermal growth factor, two well established effects of protein kinase C Swiss 3T3 fibroblasts. This emphasizes the complexity, from a functional point of view, of protein kinase C activation in vivo.

The response of anandamide is terminated by a carrier-mediated transport followed by degradation catalyzed by the cloned enzyme fatty acid amidohydrolase (FAAH). In this study, we provide biochemical data showing an anandamide uptake process and the expression of FAAH in human prostate. Anandamide was accumulated in PC-3 cells by a saturable and temperature-dependent process. Kinetic studies of anandamide uptake, determined in the presence of cannabinoid and vanilloid antagonists, revealed apparent parameters of KM=4.7+/-0.2 microm and Vmax=3.3+/-0.3 pmol min-1 (10(6) cells)-1. The accumulation of anandamide was moderately inhibited by previously characterized anandamide transporter inhibitors (AM404, UCM707 and VDM11) but was unaffected by inhibitors of other lipid transport systems (phloretin or verapamil) and moderately affected by the FAAH inhibitor methyl arachidonyl fluorophosphonate. The presence of FAAH in human prostate epithelial PC-3 cells was confirmed by analyzing its expression by Western blot and measuring FAAH activity. To further study the structural requirements of the putative carrier, we synthesized a series of structurally different compounds 1-8 and evaluated their capacity as uptake inhibitors. They showed different inhibitory capacity in PC-3 cells, with (9Z,12Z)-N-(fur-3-ylmethyl)octadeca-9,12-dienamide (4, UCM119) being the most efficacious, with maximal inhibition and IC50 values of 49% and 11.3+/-0.5 microM, respectively. In conclusion, PC-3 cells possess a complete inactivation system for anandamide formed by an uptake process and the enzyme FAAH. These results suggest a possible physiological function of anandamide in the prostate, reinforcing the role of endocannabinoid system as a neuroendocrine modulator. British Journal of Pharmacology (2004) 141, 457-467. doi:10.1038/sj.bjp.0705628

The effect of vasoactive intestinal peptide (VIP) on intracellular Ca2+ levels and its relationship with the expression of c-fos and vascular endothelial growth factor (VEGF) as well as with neuroendocrine (NE) differentiation were investigated in human prostate LNCaP cells. VIP induced the expression of c-fos mRNA as studied by reverse transcription polymerase chain reaction (RT-PCR). It was accompanied by VIP stimulation of c-fos protein synthesis, as measured by Western blot analysis. VIP enhanced intracellular Ca2+ levels as evaluated using the calcium probe fura-2. VIP regulation of c-fos expression depended on [Ca2+]i concentration since the intracellular calcium chelator BAPTA/AM decreased c-fos expression (both mRNA and protein) to basal levels. As shown by means of real-time RT-PCR, VIP stimulated VEGF mRNA expression: the effect was inhibited by 40% in the presence of curcumin (an inhibitor of AP-1 binding), and it was dependent on Ca2+ since BAPTA/AM inhibited this VIP action by 43%. Similar observations were made on the effects of BAPTA/AM and curcumin on VIP stimulation of VEGF protein expression. Simultaneous treatment of cells with the protein kinase A inhibitor H89 and BAPTA/AM completely blocked this VIP effect, whereas each agent alone led only to a partial inhibition. In addition, the calcium chelator blocked by 37% the ability of VIP to induce NE cell differentiation as estimated by the observation of neurite development. These features support a VIP signalling pathway that could be mediated through both cAMP and [Ca2+]i increase in prostate LNCaP cancer cells. Moreover, our data suggest the implication of c-Fos on the induction of the main angiogenic factor VEGF since the promoter region of the VEGF gene possesses AP-1 (i.e., c-Fos/c-Jun heterodimer) response elements. This feature represents a link between the nuclear oncogene c-fos, angiogenesis and NE differentiation by means of an initiating signal upon VIP receptors.

The key metabolic sensor adenosine monophosphate-dependent kinase (AMPK) has emerged as a promising therapeutic target for cancer prevention and treatment. Besides its role in energy homeostasis, AMPK blocks cell cycle, regulates autophagy and suppresses the anabolic processes required for rapid cell growth. AMPK is especially relevant in prostate cancer in which activation of lipogenic pathways correlate with tumor progression and aggressiveness. This study reports the discovery of a new series of 2-oxindole derivatives whose AMPK modulatory ability, as well as the antitumoral profile in prostate cancer cells, was evaluated. One of the assayed compounds, compound 8c, notably activated AMPK in cultured PC-3, DU145 and LNCaP prostate cancer cells. Likewise, compound 8c caused PC-3, DU145 and LNCaP cells viability inhibition. Selective knocking down of α1 or α2 isoforms as well as in vitro assays using human recombinant α1β1γ1 or α2β1γ1 AMPK isoforms revealed that compound 8c exhibit preference for AMPKα1. Consistent with efficacy at the cellular level, compound 8c was potent in suppressing the growth of PC-3 xenograft tumors. In conclusion, our results show that a new 2-oxindole fluorinated derivative exerts potent in vivo antitumor actions against prostate cancer cells, indicating a promising clinical therapeutic strategy for the treatment of androgen-independent prostate cancer.

The present research was undertaken to study the possible involvement of the atypical protein kinase C (PKC) ζ in ceramide signal transduction in primary cultures of rat astrocytes. As shown by Western blot analysis, translocation of immunoreactive PKCζ to the particulate fraction occurred upon exposure of astrocytes to cell‐permeable ceramide analogs or to exogenous sphingomyelinase. The particulate fraction may correspond to a perinuclear area, as indicated by immunocytochemical techniques. Furthermore, treatment of cells with N ‐octanoylsphingosine led to an increased phosphorylation of PKCζ. Results thus show that stimulation of PKCζ may be one of the intracellular events triggered by activation of the sphingomyelin pathway.

Astrocytes synthesize nerve growth factor (NGF) in response to pro-inflammatory cytokines. To further study the signaling mechanism involved in this induction of NGF production, the sphingomyelin (SM) pathway was studied. Addition of exogenous neutral SMase (Staphylococcus aureus) or C2-ceramide to primary cultures of newborn rat cortical astrocytes elicited a dose–response increase of NGF synthesis, with maximal effect at 1 U/ml and 25 μM, respectively. Induction of NGF synthesis by SMase and ceramide was shown to be independent of classical PKC activity. Intracellular cAMP-raising agents, such as forskolin and 3-isobutyl-1-methylxanthine, partially prevented the SMase- and C2-ceramide-induced secretion of NGF to the cell supernatant. PD098059 and apigenin, inhibitors of the mitogen-activated protein (MAP) kinase pathway, produced a dose–response inhibition of the SMase- and C2-cer-induced release of NGF. This observation points to the possibility that regulation of NGF synthesis and secretion by the SMase pathway may be mediated downstream by the MAP kinase cascade. As a matter of fact, pre-treatment of astrocytes with SMase or C8-ceramide led to an increased phosphorylation of raf-1. Moreover, MAP kinase activity was enhanced in astrocytes treated with SMase or both ceramides. In conclusion, results suggest that the SMase pathway may control NGF synthesis in the central nervous system, and raise the possibility of an involvement of the MAP kinase cascade in this process.

Abstract The fluorescence probe 1,6‐diphenylhexa‐1,3,5‐triene (DPH) was used for monitoring structural perturbations induced by lipopolysaccharide (LPS) of Escherichia coli (0111 : B4) in plasma membranes of rat liver. Changes in microviscosity were observed in plasma membrane preparations from control rats after treatment with LPS and in plasma membrane preparations from liver perfused with LPS. In both systems fluorescence polarization was measured from which microviscosity was calculated. This parameter increases with LPS treatment. From temperature dependence studies was inferred that LPS interaction with plasma membrane preparations induces an increase of both the polarization term ( r 0 / r –1) −1 and flow activation energy (ΔE). Addition of LPS to hepatocyte suspensions also induces an increase on microviscosity and a delay in the fall of microviscosity induced by a temperature rise in hepatocyte monolayers grown on microcover slides. These data suggest that LPS interaction can be attributed to its binding to membrane hydrophobic regions in a non‐specific manner.

Capsaicin is a natural compound present in chili and red peppers and the responsible of their spicy flavor. It has recently provoked interest because of its antitumoral effects in many cell types although its action mechanism is not clearly understood. As metabolic dysregulation is one of the hallmarks of cancer cells and the key metabolic sensor in the AMP-activated kinase (AMPK), in this study we explored the ability of capsaicin to modulate AMPK activity. We found that capsaicin activated AMPK in HepG2 cells by increasing AMPK phosphorylation and its downstream target ACC. Mechanistically, we determined that capsaicin activated AMPK through the calcium/calmodulin-dependent protein kinase kinase β, CaMKKβ as either the CaMKK inhibitor STO-609 or CaMKK knock down with siRNA abrogated the activation of AMPK. Moreover, capsaicin decreased cell viability, inhibited Akt/mTOR pathway and increased reactive oxygen species (ROS) in HepG2 cells. AMPK activation was involved in the underpinning mechanism of capsaicin-induced cell death.

Cannabinoids exert a wide spectrum of effects in men including alterations in the reproductive system. To date, two types of cannabinoid receptors have been cloned in humans, namely CB(1) and CB(2) belonging to the G protein-coupled receptor superfamily. Although cannabinoids have functional and morphologic effects in the prostate gland, the expression of cannabinoid receptors in this tissue has never been investigated. The aim of this study was to analyze the expression of cannabinoid receptors in the human prostate gland and their regulatory effects on adenylyl cyclase activity.To investigate the existence of cannabinoid receptors in prostate, we used various methods, including reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry. Adenylyl cyclase activity was analyzed by measuring the cAMP produced by means of a competitive assay by using PKA.Both mRNA for CB(1) and the corresponding protein are expressed in the human prostate gland at a level comparable with the receptor expressed in cerebellum. The molecular mass of the protein estimated from Western blot analysis was 58 kDa, which is in concordance with previous data for CB(1) in other tissues. Immunohistochemical studies show that CB(1) is preferentially expressed in the epithelia of the prostate. The cannabinoid receptor expressed in the prostate negatively regulates adenylyl cyclase activity through a pertussis toxin-sensitive protein.

In the present study, we have investigated the effect of the cannabinoid R+ methanandamide (MET) in the androgen-resistant prostate cancer PC3 cells. MET induced a dose-dependent decrease in PC3 cell viability as well as a dose-dependent increase in the secretion of the cytokine IL-6. Looking deeper into the mechanisms involved, we found that MET-induced de novo synthesis of the lipid mediator ceramide that was blocked by the ceramide synthase inhibitor Fumonisin B1. Pre-incubation of cells with the cannabinoid receptor CB2 antagonist SR 144528 (SR2), but not the CB1 antagonist Rimonabant or the TRPV1 antagonist capsazepine, partially prevented the anti-proliferative effect, the ceramide accumulation, and the IL-6-induced secretion, suggesting a CB2 receptor-dependent mechanism. Fumonisin B1 did not have any effect in the IL-6 secretion increase induced by MET. However, even an incomplete down-regulation of (i.e., not a total silencing of) ceramide kinase expression by specific siRNA prevented the MET-induced IL-6 secretion. These results suggest that MET regulates ceramide metabolism in prostate PC3 cells which is involved in cell death as well as in IL-6 secretion. Our findings also suggest that CB2 agonists may offer a novel approach in the treatment of prostate cancer by decreasing cancer epithelial cell proliferation. However, the interaction of prostate cancer cells with their surrounding, and in particular with the immune system in vivo, needs to be further explored.

Colorectal and prostate cancers are two of the most common types and cause of a high rate of deaths worldwide. Therefore, any strategy to stop or at least slacken the development and progression of malignant cells is an important therapeutic choice. The aim of the present work is the identification of novel cancer chemotherapy agents. Nowadays, many different drug discovery approaches are available, but this paper focuses on Molecular Topology, which has already demonstrated its extraordinary efficacy in this field, particularly in the identification of new hit and lead compounds against cancer. This methodology uses the graph theoretical formalism to numerically characterize molecular structures through the so called topological indices. Once obtained a specific framework, it allows the construction of complex mathematical models that can be used to predict physical, chemical or biological properties of compounds. In addition, Molecular Topology is highly efficient in selecting and designing new hit and lead drugs. According to the aforementioned, Molecular Topology has been applied here for the construction of specific Akt/mTOR and β-catenin inhibition mathematical models in order to identify and select novel antitumor agents.Based on the results obtained by the selected mathematical models, six novel potential inhibitors of the Akt/mTOR and β-catenin pathways were identified. These compounds were then tested in vitro to confirm their biological activity.Five of the selected compounds, CAS n° 256378-54-8 (Inhibitor n°1), 663203-38-1 (Inhibitor n°2), 247079-73-8 (Inhibitor n°3), 689769-86-6 (Inhibitor n°4) and 431925-096 (Inhibitor n°6) gave positive responses and resulted to be active for Akt/mTOR and/or β-catenin inhibition. This study confirms once again the Molecular Topology's reliability and efficacy to find out novel drugs in the field of cancer.

Cannabinoids, the active components of marihuana, exert a variety of effects in humans. Many of these effects are mediated by binding to two types of cannabinoid receptor, CB1 and CB2. Although CB1 is located mainly in the central nervous system, it may also be found in peripheral tissues. Here, we study the effect of cannabinoids in the production of nerve growth factor by the prostate tumor cell line PC‐3. We show that addition of Δ 9 ‐tetrahydrocannabinol to PC‐3 cells stimulated nerve growth factor production in a dose‐dependent and time‐dependent manner. Maximal effect was observed at 0.1 µ m Δ 9 ‐tetrahydrocannabinol and 72 h of treatment. Stimulation was reversed by the CB1 antagonists AM 251 and SR 1411716A. Pre‐treatment of cells with pertussis toxin also prevented the effect promoted by Δ 9 ‐tetrahydrocannabinol. These results indicate that Δ 9 ‐tetrahydrocannabinol stimulation of nerve growth factor production in these cells was mediated by the cannabinoid CB1 receptor. The implication of Raf‐1 activation in the mode of action of Δ 9 ‐tetrahydrocannabinol is also suggested.

In this study, we examined the metabolic adaptations of a chemoresistant prostate cancer cell line in comparison to a sensitive cell line. We utilized prostate cancer LNCaP cells and subjected them to a stepwise increase in the antiandrogen 2-hydroxy-flutamide (FLU) concentration to generate a FLU-resistant cell line (LN-FLU). These LN-FLU cells displayed characteristics of cancer stem cells, exhibited drug resistance, and showed a significantly reduced expression of Cyclin D1, along with the overexpression of p16, pointing to a proliferation arrest. In comparing the cancer stem-like LN-FLU cells to the LNCaP cells, we observed a decrease in the expression of CTP-choline cytidylyl transferase α (CCTα), as well as a decline in choline kinase, suggesting altogether a downregulation of the phosphatidylcholine biosynthetic pathway. In addition, we found decreased levels of the protein methyl transferase PRMT2 and the upregulation of the histone deacetylase Sirtuin1 (Sirt1). Analysis of the human prostate cancer samples revealed similar results in a population with high expressions of the stem cell markers Oct4 and ABCB1A1. Our findings suggest that the adaptation of prostate cancer cells to antiandrogens could induce reprogramming into stem cells that survive in a low phosphocholine metabolism and cell cycle arrest and display drug resistance.

This study was undertaken due to the urgent need to explore reliable biomarkers for early SARS-CoV-2 infection. We performed a retrospective study analyzing the serum levels of the cardiovascular biomarkers IL-6, TNF-α, N-terminal pro-B natriuretic peptide, cardiac troponin T (cTnT), ischemia-modified albumin (IMA) and pregnancy-associated plasma protein-A (PAPP-A) in 84 patients with COVID-19.Patients were divided into three groups according to their RT-qPCR and IgG values: acute infection (n = 35), early infection (n = 25) or control subjects (n = 24). Levels of biomarkers were analyzed in patient serum samples using commercially available ELISA kits. Results showed a significant increase in IMA and PAPP-A levels in the early infected patients. Moreover, multivariate analysis and receiver operating characteristic (ROC) curve showed that IMA and PAPP-A had excellent discrimination value for the early stage of COVID-19. For IMA, the area under the ROC curve (AUC) had a value of 0.94 (95% confidence interval (CI): 0.881-0.999). Likewise, the serum level of PAPP-A was significantly higher in patients with early infection than in the control subjects (AUC = 0.801 (95% CI: 0.673-0.929)). The combined use of IMA and PAPP-A enhanced the sensitivity for total SARS-CoV-2-infected patients to 93%. These results suggest that the increased levels of PAPP-A and IMA shed light on underlying mechanisms of COVID-19 physiopathology and might be used as efficient biomarkers with high sensitivity and specificity for the early stage of COVID-19. Importantly, when monitoring pregnancy and cardiovascular diseases using PAPP-A or IMA levels, a SARS-CoV-2 infection should be discarded for proper interpretation of the results.

Chemoresistance is one of the most important challenges in cancer therapy. The presence of cancer stem cells within the tumor may contribute to chemotherapy resistance since these cells express high levels of extrusion pumps and xenobiotic metabolizing enzymes that inactivate the therapeutic drug. Despite the recent advances in cancer cell metabolism adaptations, little is known about the metabolic adaptations of the cancer stem cells resistant to chemotherapy. In this study, we have undertaken an untargeted metabolomic analysis by liquid chromatography-high-resolution spectrometry combined with cytotoxicity assay, western blot, quantitative real-time polymerase chain reaction (qPCR), and fatty acid oxidation in a prostate cancer cell line resistant to the antiandrogen 2-hydroxiflutamide with features of cancer stem cells, compared to its parental androgen-sensitive cell line. Metabolic fingerprinting revealed 106 out of the 850 metabolites in ESI+ and 67 out of 446 in ESI- with significant differences between the sensitive and the resistant cell lines. Pathway analysis performed with the unequivocally identified metabolites, revealed changes in pathways involved in energy metabolism as well as posttranscriptional regulation. Validation by enzyme expression analysis indicated that the chemotherapy-resistant prostate cancer stem cells were metabolically dormant with decreased fatty acid oxidation, methionine metabolism and ADP-ribosylation. Our results shed light on the pathways underlying the entry of cancer cells into dormancy that might contribute to the mechanisms of drug resistance.

The role of the beta-adrenoceptor-G-protein-adenylate cyclase system in the pathogenesis of cardiac hypertrophy was studied. We have used a minipig model of pressure-overload cardiac hypertrophy secondary to aortic banding. Four groups of five animals were used: minipigs made hypertrophic were evaluated 2 months (CH2 group) and 9 months (CH9 group) later and compared to controls (C2 and C9 groups, respectively). A decrease in beta-adrenergic receptor density and an increase in antagonist affinity were shown in left ventricular membranes of hypertrophied animals compared with controls. In both groups, CH2 and CH9, an increase in EC50 for isoproterenol-stimulated adenylate cyclase activity, an increase in forskolin-stimulated adenylate cyclase activity and a diminished inhibition by carbachol of isoproterenol-stimulated adenylate cyclase were observed. In contrast, fluoride-stimulated adenylate cyclase activity was markedly increased only in the end stage of hypertrophy. alpha s-cholera toxin-catalysed ADP-ribosylation is increased in early hypertrophy and then decreases with late hypertrophy and a similar pattern is observed with alpha o pertussis toxin-catalysed ADP-ribosylation, whereas alpha i-ADP-ribosylation remains unchanged. Tissue content of Gs-, Gi- and Go-proteins, as assessed by specific antibodies, was found unchanged in CH9 and CH2 groups when compared with that in C9 and C2 control groups, respectively. Modifications in Gs functional activity in later hypertrophic stages, expressed as alterations in cholera toxin ADP-ribosylation and adenylate cyclase fluoride responsiveness, may be important in the pathogenesis of decompensation from compensated hypertrophy to cardiac failure.

Reversible endotoxic shock was induced in adult rats by i.v. injection of Escherichia coli O111:B4 lipopolysaccharide (1.6 mg/100 g). The shock progression was evaluated by measuring serum glucose levels as well as activities of aspartate aminotransferase (GOT) and alkaline phosphatase in serum. A rapid increase of serum glucose levels occurs, after LPS injection, followed by hypoglycaemia (minimum values at 6 h) with progressive reversion to control values. Serum GOT activity increased (twofold) 6 h after endotoxin administration and returned to control values at 72 h. No appreciable changes occurred in serum alkaline phosphatase activity. Endotoxaemia produced a decrease in the cytochrome P-450 levels in all target organs considered: lung, adrenal glands and liver. The progressive decrease in the serum albumin concentration as well as changes of the physical properties of the plasma membranes observed in vivo, can not be explained only by direct interaction of endotoxin with the target organs, underlining the importance of serum mediators in the induction of the shock response.

Abstract Capsaicin (CAP) ist seit Längerem für dessen analgetische Wirkung sowie seit Kurzem für seine Antitumoraktivität an verschiedenen Zelltypen bekannt. Aufgrund seiner Schärfe und der benötigten hohen Dosen zur Erzielung einer signifikanten Aktivität hat dieser Wirkstoff bis heute keine Anwendung in der Krebstherapie gefunden. In dieser Arbeit zeigen wir eine neuartige Strategie, um die Aktivität dieses Wirkstoffes zu verbessern. Durch den Austausch der hydrophoben Terpeneinheit durch einen BODIPY‐Farbstoff wurde die Neigung zur Aggregation erhöht. Die Verbindung CAP‐BDP 1 lagert sich in wässrigen Medien zu schwach fluoreszierenden sphärischen Anordnungen zusammen, die durch die Aufnahme in die Zelle zur hoch fluoreszierenden Monomereinheiten disassemblieren. Bemerkenswert ist, dass der Transport in das Tumorgewebe mithilfe dieser Aggregate verbessert werden und somit die wirksame Dosis in vivo bei Prostatakrebszellen um zwei Größenordnungen reduziert werden konnte.

The signal mechanism underlying tumor necrosis factor alpha (TNF alpha) up-regulation of nerve growth factor (NGF) production was studied in primary rat astrocyte cultures. Because ceramide is also able to induce NGF secretion and because TNF alpha is a known agonist of the sphingomyelin (SPM)-ceramide pathway, we investigated whether the TNF alpha-induced NGF secretion by primary astrocytes is mediated by ceramide. TNF alpha stimulation of NGF secretion was shown to be independent of protein kinase C, abrogated by the tyrosine phosphoprotein phosphatase inhibitor phenylarsine oxide (PAO), and independent of the activation of the mitogen-activated protein kinase (MAPK) cascade. In marked contrast, inhibition of MAPK counteracted the NGF secretion induced by ceramide. TNF alpha stimulation of the nuclear transcription factor NF-kappaB was prevented by cell pretreatment with PAO, whereas ceramide and sphingomyelinase had a marginal effect on NF-kappaB activation. Moreover, TNF alpha failed to activate the SPM pathway, as indicated by the lack of SPM degradation and the absence of ceramide generation. To clarify further the role of NF-kappaB in NGF synthesis, electrophoretic mobility shift assays were performed with an NF-kappaB site from the NGF promoter. The absence of significant binding of NF-kappaB to the NGF gene promoter indicates the existence of an indirect role of NF-kappaB in the regulation of NGF synthesis. Altogether, our data strongly suggest that TNF alpha-mediated up-regulation of NGF occurs independently of ceramide generation.

The precise mechanisms involved in the endotoxin-induced shock are not yet clearly understood. A biphasic behaviour has been observed due to a direct interaction of bacterial lipopolysaccharide (LPS) with the membrane of target cells and an indirect activation of multiple homeostatic regulatory mechanisms (3).

The biphasic behaviour observed in endotoxin-induced shock attributed to a direct interaction of bacterial lipopolysaccharides with the cell membrane and an indirect activation of multiple homeostatic regulatory mechanisms, cannot be completely elucidated with in vivo studies. In primary cultures of adult rat hepatocytes, lipopolysaccharide from Escherichia coli 0111:B4 affects the cytochrome P450 levels directly; however, albumin and aspartate aminotransferase secretion are induced by some mediators present in the sera of animals in acute-phase shock.

Current therapies against prostate cancer (PCa) disease, such as surgery, radiotherapy, or in last term chemical castration by androgen deprivation, have led to significant reduction of the incidence of PCa throughout the world. Worse prognosis is found in those patients which exhibit castration resistance, relapsing into the disease with even greater aggressiveness. Hypoxia cancer cell adaption has been observed to be closely connected to fatal prognostic tumor features. Therefore, hypoxia adaptive mechanisms of cancer cells have attracted large interest as a relevant biological target for treatment-resistant patients. Dendrimers have been established as a promising nanotechnological tool owing to their beneficial physicochemical features such as multivalency and monodispersity. Herein, we have completed a thorough study to better understand the effect within the cell of the already published ruthenium(II)-N-heterocyclic carbene metallodendrimer (G2Ru) that was able to drastically reduce HIF-1α stabilization and exhibited antiproliferative capability against androgen-sensitive (LNCaP) and androgen-resistant prostate cancer cells (LNFLU) in vitro. G2Ru, as well as its cationic imidazolium precursor (G2P), displayed scavenging properties against intracellular and externally stimulated ROS levels, which would presumably hinder the stabilization of HIF-1α by prolyl hydroxylase (PHD) inhibition. Furthermore, these dendrimers have shown considerably beneficial properties against tumor progression capability in terms of apoptosis, cell cycle, CSCs expression, and epithelial phenotype promotion. Taken all together, in this study we could demonstrate the extraordinary anticancer properties of NHC-based carbosilane dendrimers against androgen-resistant prostate cancer cells in vitro.

Lipopolysaccharides (LPS) from Gram-negative bacteria are considered to be the responsible agents for the induction of endotoxic shock, affecting the liver as a target organ. In this study, the cell morphology and some biochemical properties of 24 h-culture-hepatocyte monolayers treated with Escherichia coli 0111:B4 lipopolysaccharide, were observed. Cell morphology was observed by scanning electron microscopy and immunofluorescence methods. LPS interaction induced an increase in rounded cells with diminished adhesion capacity. As biochemical parameters, albumin synthesis and 2-deoxyglucose uptake were measured. LPS decreased the hexose uptake in a dose-dependent manner. Binding of (14C)LPS to cultured hepatocytes showed that LPS binds to non-specific constituents of the membrane bilayer.

The adaptive response to endurance exercise of the catecholamine- and glucagon-sensitive adenylyl cyclase system was studied in rat liver plasma membranes. Endurance exercise enhanced adenylyl cyclase system activation by cellular agonists (glucagon, isoproterenol), by stimulators of the enzyme catalytic subunit (forskolin, Mn2+), and by Gs-protein activators (GppNHp, fluoride). In addition, endurance exercise increased the levels of G50, Gi alpha, and G beta subunits. These results show that the adenylyl cyclase system becomes sensitized in response to physical training.

In order to clarify the endotoxin effect on the hepatic removal of insulin, the influence of lipopolysaccharide (LPS) from E. coli 0111:B4 on the insulin binding and endocytosis in cultured hepatocytes from adult male rats has been investigated. LPS decreases both processes in a time and temperature-dependent manner, showing a major effect at short time and low temperature, according to the characteristics of LPS binding and uptake.

Phosphatidylcholine breakdown has been shown to play a critical role in signal transduction involving generation of a number of second messengers [Exton, J.H., Biochim. Biophys. Acta, 1212 (1994) 26-42]. In the present report we demonstrate by immunofluorescence that short-treatment of C 6 glial cells with phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC), changes the intracellular localization of protein kinase C (PKC) zeta from the cytoplasm to a perinuclear region. Western blot analysis also showed a redistribution of PKC zeta after incubation of cells with PC-PLC. To test whether these changes were accompanied by an activation of the enzyme, we measured the extent of phosphorylation of PKC zeta by immunoprecipitation from 32P-labelled cells. Short-treatment with PC-PLC resulted in enhanced phosphorylation of the higher Mr PKC zeta in C 6 glial cells.

Throughout the pandemic, serological assays have been revealed as crucial for detecting previous exposures to the virus and determining the timing of antibody maintenance after vaccination or natural infection. This study aimed to develop an optimized enzyme-linked immunosorbent assay (ELISA)-based serology, which could be used in case of reagent shortages, such as that occurred in the beginning of this health emergency. As a result, we present a high-sensitive immunoassay for the determination of IgG levels in venous serum samples, using 2 μg/mL antigen (receptor-binding domain of the spike protein S1) for coating the plate and utilizing human samples at a dilution 1:1000. This method showed non-inferiority features versus a commercial kit, is less expensive, and has a higher spectrophotometric range that allows for a better quantification of the antibody titers. The optical density values before and after heating venous serum samples at 56 °C during 30 min was quite similar, showing that heat inactivation can be used to reduce the biohazardous risks while handling samples. Furthermore, we show that finger-stick capillary blood samples can also serve as a suitable source for IgG detection, bypassing the need for serum isolation and being suitable for point-of-care application (Pearson's coefficient correlation with capillary serum was 0.95, being statistically significant).

Reversible endotoxic shock was induced in adult rats by intravenous injection of E. coli 0111:B4 lipopolysaccharide (LPS) and the progression of metabolic and morphological alterations was evaluated. Serum samples and biopsies from adrenal gland, liver and lung were studied at different times after LPS injection. Histological changes in these tissues were observed after endotoxin administration, coinciding with both the acute-phase and the recovery-phase of shock (24-72h after LPS injection). Signs of tissue regeneration can be correlated with the regression of some serum parameters to their normal values. All these results indicate that in this experimental model of endotoxic shock, a reversible status was established, which will allow further studies of the endotoxic pathophysiological mechanisms in vivo, avoiding the complexity of the non-reversible process.

Este trabajo ha recibido financiacion del Ministerio de Educacion y Ciencia (SAF-2005-00602)

La dramatizacion creativa es una estrategia didactica con muchos antecedentes (Ward, W. Creative Dramatics . D. Appleton & Co., N.Y. 1930), pero poco conocida en la ensenanza superior de ciencias (Scherr, R.E., et al. PER Conference 2010, 1289:293-296). Es una estrategia educativa sin finalidad de exhibicion y percibida como improvisada por los participantes, los cuales interpretan y recrean un proceso con sus acciones guiadas sobre la marcha por un instructor. Su proposito no es formar actores ni actuar para otros, sino facilitar la adquisicion de un conocimiento desde la vivencia interna y la autoobservacion. En humanidades suele consistir en la interpretacion de roles humanos o sociales en situaciones determinadas, pero en ciencias es una representacion figurada de un proceso cientifico complejo, donde los participantes asumen el papel de distintos componentes o elementos que intervienen, teniendo que representar objetos o conceptos abstractos y alejados de la percepcion real o de la escala humana. La dramatizacion facilita el aprendizaje significativo y la clarificacion de conceptos abstractos, asi como la comprension de procesos complejos a traves de una toma de consciencia “desde dentro” de los propios elementos que juegan un papel en los mismos (Michael, J. In pursuit of meaningful learning. Advances in Physiology Education , 2001, 25:145-158; Dee Fink, L. Creating Significant Learning Experiences: An Integrated Approach to Designing College Courses . 2003, Josey-Bass, Wiley. San Francisco, CA 94103-1741). Esta actividad promueve un aprendizaje mediante la autoobservacion, aprovechando la capacidad humana natural de representar la propia percepcion de fenomenos complejos para comprenderlos. La dramatizacion creativa estimula el pensamiento logico e intuitivo, interioriza el conocimiento y genera un placer estetico que facilita un aprendizaje significativo y memorable. En esta comunicacion se presentan ejemplos practicos, como la contraccion muscular, el bombeo de protones en la cadena respiratoria, la eliminacion de intrones, compuestos intercalantes de ADN y fluorescencia, o la electroforesis en gel. Todos ellos son originales y han sido aplicados en muchos cursos para estimular la participacion de los alumnos y activar un aprendizaje significativo.

ResumenLos compuestos naturales que tienen efectos beneficiosos para la salud han tomado relevancia como nuevos fármacos, al presentar la capacidad de modular distintos procesos celulares.Dentro de este grupo encontramos la capsaicina que es la responsable de la "sensación de calor" que produce el picante.Recientemente ha provocado gran interés debido a sus efectos antitumorales en muchos tipos de células, aunque su mecanismo de acción en muchos casos no ha sido descrito.Como recientemente se ha descrito que la desregulación metabólica es una característica de las células cancerosas y la quinasa activada por AMP (AMPK) es el sensor clave en el metabolismo, nos planteamos si la capsaicina es capaz de modular la actividad de AMPK y el posible mecanismo implicado.Los resultados mostraron que la capsaicina activa AMPK en las células HepG2 al aumentar su fosforilación y la de su sustrato directo ACC.Por otro lado, determinamos que la activación de AMPK inducida por capsaicina, se produce a través de la proteína quinasa de la quinasa dependiente de calcio/calmodulina tipo β (CaMKKβ).Ya que se bloquea al silenciar CaMKK β con siRNA o al bloquearla farmacológicamente con el inhibidor STO-609.Además, la capsaicina disminuye la viabilidad celular en células HepG2, efecto que ejerce a través de la activación de AMPK.

Appears in: EDULEARN21 Proceedings Publication year: 2021Pages: 11402-11410ISBN: 978-84-09-31267-2ISSN: 2340-1117doi: 10.21125/edulearn.2021.2375Conference name: 13th International Conference on Education and New Learning TechnologiesDates: 5-6 July, 2021Location: Online Conference

Abstract Background This study has been undertaken with the urgent need for exploring reliable biomarkers for early infection of SARS-CoV-2. We performed a retrospective study analyzing the serum levels of the cardiovascular biomarkers N-terminal pro-B natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), Ischemia Modified Albumin (IMA) and pregnancy associated plasma protein A (PAPP-A), in 84 patients with COVID-19. Methods Patients were divided in three groups according to their RT-qPCR and IgG values in acute infection (n=35), early infection (n=25) or control subjects (n=24). Levels of biomarkers were analyzed in patient’s serum samples by commercially available ELISA kits. Results Multivariate analysis and Receiver Operating Characteristic (ROC) curve showed that IMA and PAPP-A, had an excellent discrimination value for the early stage of COVID-19. Serum levels of IMA in early SARS-CoV-2 infected patients were significantly higher than in the control group with an area under the ROC curve (AUC) value of 0.94 (95% confidence interval (CI): 0.881- 0.999). Likewise, the serum level of PAPP-A was significantly higher in patients with early infection than in controls [AUC = 0.801 (95% CI: 0.673–0.929)]. The combined use of IMA and PAPP-A enhanced the sensitivity for total SARS-CoV-2 infected patients to 93%. Conclusions These results suggest that the levels of PAPP-A and IMA might be used as efficient biomarkers for the early stage of COVID-19 with high sensitivity and specificity. Importantly, when monitoring pregnancy and cardiovascular diseases by PAPP-A or IMA levels, an infection by SARS-CoV-2 should be discarded for proper interpretation of the results.

Abstract Recently, natural compounds and their derivatives have been reported to have anti-cancer effects. Herein, we investigated the mechanism whereby the natural vanilloid capsaicin exerts anti-tumor effects on prostate cancer cells. We found that capsaicin activates the AMP-activated kinase (AMPK) and promotes cell death in the LKB1 expressing prostate cancer cell lines LNCaP and PC3 but not in the LKB1-null cell line DU-145. Capsaicin treatment stimulated LKB1 phosphorylation and activated AMPK in LKB1 expressing cells. In addition, overexpression of LKB1 by lentiviral infection in DU-145 cells, induced capsaicin-triggered AMPK activation and apoptosis while LKB1 silencing in LNCaP and PC3 cells, increased capsaicin-promoted cell death. Capsaicin-induced LKB1 phosphorylation, was dependent on the transient receptor potential cation channel subfamily V member 1 (TRPV1), since TRPV1 knocked down by shRNA, abolished LKB1 and AMPK phosphorylation and inhibited apoptosis. Altogether, our results show that capsaicin affect AMPK activity in an LKB1- and TRPV1-dependent fashion, linking TRPV1 with cell fate. These data also suggest that capsaicin may be a rational therapeutic option for prostate tumors.

Conference Abstract| October 01 2000 Δ9 Tetrahydrocannabinol increases nerve growth factor production by prostate PC-3 cells. Involvement of CB1 cannabinoid receptor M. L. Velasco; M. L. Velasco 1Department of Biochemistry and Molecular Biology, School of Medicine, University of Alcalá, 28871 Madrid, Spain Search for other works by this author on: This Site PubMed Google Scholar L. Ruiz; L. Ruiz 1Department of Biochemistry and Molecular Biology, School of Medicine, University of Alcalá, 28871 Madrid, Spain Search for other works by this author on: This Site PubMed Google Scholar M. G. Sánchez; M. G. Sánchez 1Department of Biochemistry and Molecular Biology, School of Medicine, University of Alcalá, 28871 Madrid, Spain Search for other works by this author on: This Site PubMed Google Scholar I. Díaz-Laviada I. Díaz-Laviada 1Department of Biochemistry and Molecular Biology, School of Medicine, University of Alcalá, 28871 Madrid, Spain Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 2000 Biochemical Society2000 Biochem Soc Trans (2000) 28 (5): A339. https://doi.org/10.1042/bst028a339a Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation M. L. Velasco, L. Ruiz, M. G. Sánchez, I. Díaz-Laviada; Δ9 Tetrahydrocannabinol increases nerve growth factor production by prostate PC-3 cells. Involvement of CB1 cannabinoid receptor. Biochem Soc Trans 1 October 2000; 28 (5): A339. doi: https://doi.org/10.1042/bst028a339a Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 2000 Biochemical Society2000 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Abstract| January 01 1994 Rat Liver Adenylyl Cyclase and Endurance Training JL Nieto; JL Nieto 1Dept. Bioquímica. Fac. Químicas. Universidad Complutense. 28040 Madrid. Spain Search for other works by this author on: This Site PubMed Google Scholar I Diaz-Laviada; I Diaz-Laviada 1Dept. Bioquímica. Fac. Químicas. Universidad Complutense. 28040 Madrid. Spain Search for other works by this author on: This Site PubMed Google Scholar A Haro A Haro 1Dept. Bioquímica. Fac. Químicas. Universidad Complutense. 28040 Madrid. Spain Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (1994) 87 (s1): 57. https://doi.org/10.1042/cs087s057 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation JL Nieto, I Diaz-Laviada, A Haro; Rat Liver Adenylyl Cyclase and Endurance Training. Clin Sci (Lond) 1 January 1994; 87 (s1): 57. doi: https://doi.org/10.1042/cs087s057 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1994 The Biochemical Society and the Medical Research Society1994 Article PDF first page preview Close Modal You do not currently have access to this content.