Activation of mutated TRPA1 ion channel by resveratrol in human prostate cancer associated fibroblasts (CAF)

Previous studies showed the effects of resveratrol (RES) on several cancer cells, including prostate cancer (PCa) cell apoptosis without taking into consideration the impact of the tumor microenvironment (TME). The TME is composed of cancer cells, endothelial cells, blood cells and cancer-associated fibroblasts (CAF), the main source of growth factors. The latter cells might modify in the TME the impact of RES on tumor cells via secreted factors. Recent data clearly show the impact of CAF on cancer cells apoptosis resistance via secreted factors. However, the effects of RES on PCa CAF have not been studied so far. We have investigated here for the first time the effects of RES on the physiology of PCa CAF in the context of TME. Using a prostate cancer CAF cell line and primary cultures of CAF from prostate cancers, we show that RES activates the N-terminal mutated Transient Receptor Potential Ankyrin 1 (TRPA1) channel leading to an increase in intracellular calcium concentration and the expression and secretion of growth factors (HGF and VEGF) without inducing apoptosis in these cells. Interestingly, in the present work, we also show that when the prostate cancer cells were co-cultured with CAF, the RES-induced cancer cell apoptosis was reduced by 40%, an apoptosis reduction canceled in the presence of the TRPA1 channel inhibitors. The present work highlights CAF TRPA1 ion channels as a target for RES and the importance of the channel in the epithelial-stromal crosstalk in the TME leading to resistance to the RES-induced apoptosis

Expression and Role of T-type Calcium Channels during Neuroendocrine Differentiation

Neuroendocrine cells release their secretion into the extracellular environment through calcium-dependentsignalling pathways. These cells share common morphological and molecular features such as the expression ofspecific biomarkers, neurite outgrowth and dense core secretory granules. In order to elucidate the signallingpathways leading from undifferentiated to differentiated neuroendocrine cells, the role of voltage-dependent calciumchannels, central actors in the excitation-secretion coupling, has been comprehensively investigated. T-type calciumchannels appear to belong to the most important ion channel family involved in the neuroendocrine differentiationprocess. They could also participate in the development of neuroendocrine tumours

Expression and Role of T-type Calcium Channels during Neuroendocrine Differentiation

International audienceNeuroendocrine cells release their secretion into the extracellular environment through calcium-dependentsignalling pathways. These cells share common morphological and molecular features such as the expression ofspecific biomarkers, neurite outgrowth and dense core secretory granules. In order to elucidate the signallingpathways leading from undifferentiated to differentiated neuroendocrine cells, the role of voltage-dependent calciumchannels, central actors in the excitation-secretion coupling, has been comprehensively investigated. T-type calciumchannels appear to belong to the most important ion channel family involved in the neuroendocrine differentiationprocess. They could also participate in the development of neuroendocrine tumours

Bisphenol A stimulates human prostate cancer cell migration via remodelling of calcium signalling

International audienceBisphenol A (BPA), the principal constituent of reusable water bottles, metal cans, and plastic food containers, has been shown to be involved in human prostate cancer (PCa) cell proliferation. The aim of the present study was to explore the effect of BPA on PCa cell migration and the pathways involved in these processes. Using the transwell technique, we clearly show for the first time that the pre-treatment of the cells with BPA (1-10 nM) induces human PCa cell migration. Using a calcium imaging technique, we show that BPA pre-treatment induces an amplification of Store-Operated Calcium Entry (SOCE) in LNCaP cells. RT-PCR and Western blot experiments allowed the identification of the ion channel proteins which are up-regulated by BPA pre-treatments. These include the Orai1 protein, which is known as an important SOCE actor in various cell systems, including human PCa cells. Using a siRNA strategy, we observed that BPA-induced amplification of SOCE was Orai1-dependent. Interestingly, the BPA-induced PCa cell migration was suppressed when the calcium entry was impaired by the use of SOCE inhibitors (SKF96365, BTP2), or when the extracellular calcium was chelated. Taken together, the results presented here show that BPA induces PCa cells migration via a modulation of the ion channel protein expression involved in calcium entry and in cancer cell migration. The present data provide novel insights into the molecular mechanisms involved in the effects of an environmental factor on cancer cells and suggest both the necessity of preventive measures and the possibility of targeting ion channels in the treatment of PCa cell metastasis

Functional coupling between large-conductance potassium channels and Cav3.2 voltage-dependent calcium channels participates in prostate cancer cell growth

Summary It is strongly suspected that potassium (K+) channels are involved in various aspects of prostate cancer development, such as cell growth. However, the molecular nature of those K+ channels implicated in prostate cancer cell proliferation and the mechanisms through which they control proliferation are still unknown. This study uses pharmacological, biophysical and molecular approaches to show that the main voltage-dependent K+ current in prostate cancer LNCaP cells is carried by large-conductance BK channels. Indeed, most of the voltage-dependent current was inhibited by inhibitors of BK channels (paxillin and iberiotoxin) and by siRNA targeting BK channels. In addition, we reveal that BK channels constitute the main K+ channel family involved in setting the resting membrane potential in LNCaP cells at around −40 mV. This consequently promotes a constitutive calcium entry through T-type Cav3.2 calcium channels. We demonstrate, using single-channel recording, confocal imaging and co-immunoprecipitation approaches, that both channels form macromolecular complexes. Finally, using flow cytometry cell cycle measurements, cell survival assays and Ki67 immunofluorescent staining, we show that both BK and Cav3.2 channels participate in the proliferation of prostate cancer cells

A systematic method introduced a common lncRNA-miRNA-mRNA network in the different stages of prostate cancer

IntroductionThe present study aimed to investigate the interaction of the common lncRNA-miRNA-mRNA network involved in signaling pathways in different stages of prostate cancer (PCa) by using bioinformatics and experimental methods.MethodsSeventy subjects included sixty PCa patients in Local, Locally Advanced, Biochemical Relapse, Metastatic, and Benign stages, and ten healthy subjects were entered into the current study. The mRNAs with significant expression differences were first found using the GEO database. The candidate hub genes were then identified by analyzing Cytohubba and MCODE software. Cytoscape, GO Term, and KEGG software determined hub genes and critical pathways. The expression of candidate lncRNAs, miRNAs, and mRNAs was then assessed using Real-Time PCR and ELISA techniques.Results4 lncRNAs, 5 miRNAs, and 15 common target genes were detected in PCa patients compared with the healthy group. Unlike the tumor suppressors, the expression levels of common onco-lncRNAs, oncomiRNAs, and oncogenes showed a considerable increase in patients with advanced stages; Biochemical Relapse and Metastatic, in comparison to the primary stages; Local and Locally Advanced. Additionally, their expression levels significantly increased with a higher Gleason score than a lower one.ConclusionIdentifying a common lncRNA-miRNA-mRNA network associated with prostate cancer may be clinically valuable as potential predictive biomarkers. They can also serve as novel therapeutic targets for PCa patients

Alpha1-adrenergic receptors activate Ca(2+)-permeable cationic channels in prostate cancer epithelial cells.

The prostate gland is a rich source of alpha1-adrenergic receptors (alpha1-ARs). alpha1-AR antagonists are commonly used in the treatment of benign prostatic hyperplasia symptoms, due to their action on smooth muscle cells. However, virtually nothing is known about the role of alpha1-ARs in epithelial cells. Here, by using two human prostate cancer epithelial (hPCE) cell models - primary cells from resection specimens (primary hPCE cells) and an LNCaP (lymph node carcinoma of the prostate) cell line - we identify an alpha1A subtype of adrenergic receptor (alpha1A-AR) and show its functional coupling to plasmalemmal cationic channels via direct diacylglycerol (DAG) gating. In both cell types, agonist-mediated stimulation of alpha1A-ARs and DAG analogues activated similar cationic membrane currents and Ca(2+) influx. These currents were sensitive to the alpha1A-AR antagonists, prazosin and WB4101, and to transient receptor potential (TRP) channel blockers, 2-aminophenyl borate and SK&F 96365. Chronic activation of alpha1A-ARs enhanced LNCaP cell proliferation, which could be antagonized by alpha1A-AR and TRP inhibitors. Collectively, our results suggest that alpha1-ARs play a role in promoting hPCE cell proliferation via TRP channels

Involvement of Ion Channels in Endothelin-1-induced Signalling in Human Prostate Cancer Cells

Objective: Endothelin-1 (ET-1), a potent vasoconstrictor secreted primarily by endothelial and various epithelial cancercells has been implicated in prostate cancer progression and the ET axis has been suggested to represent a novel andexciting target in the treatment of prostate cancer (PCa). ET-1, acting primarily through the endothelin receptors (ETRs)is integrally involved in multiple facets of PCa progression, including cell growth, inhibition of apoptosis, angiogenesis anddevelopment of bone metastases. ET-1 and ETRs are expressed in PCa tissues and their expression is modulated duringthe evolution of these cancers. The purpose of the present work was to study the effects of ET-1 on proliferation of humanPCa cells PC-3 and the mechanisms by which the activation of ETRs may promote the PCa cells growth.Methods: Prostate cancer cell lines and primary cultured epithelial cells from prostate cancer, RT-PCR and calciumimaging techniques were used to study the expression and functionality of the Endothelin receptors and involvement ofion channels in the effects of ET-1 in prostate cancer cells.Results: We show for the first time that the application of ET-1 induces a dose-dependent cell proliferation andan increase in intracellular free Ca2+ concentrations ([Ca2+]i) via a mobilisation of the internal calcium stores and bya capacitative calcium entry (CCE). These effects of ET-1 were completely abolished by BQ123, a selective ETARantagonist, but not by BQ788, a selective ETBR antagonist. By use of pharmacological inhibitors and siRNA targetingcalcium-activated (IKCa1 and BKCa) potassium channels and calcium channels (TRPC1, TRPV6, Orai1), we showedthat these ion channels play an important role in calcium entry and cell proliferation induced by ET-1 in PCa cells.Conclusion: These results suggest that these ions channels evidenced here might constitute potential targets toblock the ET axis in human prostate cancers