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LNCaP Cells (lncap + cell)
Terms modified by LNCaP Cells Selected AbstractsHighly efficient capture and enumeration of low abundance prostate cancer cells using prostate-specific membrane antigen aptamers immobilized to a polymeric microfluidic deviceELECTROPHORESIS, Issue 18 2009Udara Dharmasiri Abstract Prostate tumor cells over-express a prostate-specific membrane antigen (PSMA) that can be used as a marker to select these cells from highly heterogeneous clinical samples, even when found in low abundance. Antibodies and aptamers have been developed that specifically bind to PSMA. In this study, anti-PSMA aptamers were immobilized onto the surface of a capture bed poised within a PMMA, microchip, which was fabricated into a high-throughput micro-sampling unit (HTMSU) used for the selective isolation of rare circulating prostate tumor cells resident in a peripheral blood matrix. The HTMSU capture bed consisted of 51 ultra-high-aspect ratio parallel curvilinear channels with a width similar to the prostate cancer cell dimensions. The surface density of the PSMA-specific aptamers on an ultraviolet-modified PMMA microfluidic capture bed surface was determined to be 8.4×1012,molecules/cm2. Using a linear velocity for optimal cell capture in the aptamer-tethered HTMSU (2.5,mm/s), a recovery of 90% of LNCaP cells (prostate cancer cell line; used as a model in this example) was found. Due to the low abundance of these cells, the input volume required was 1,mL and this could be processed in ,29,min using an optimized linear flow rate of 2.5,mm/s. Captured cells were subsequently released intact from the affinity surface using 0.25%,w/w trypsin followed by counting individual cells using a contact conductivity sensor integrated into the HTMSU that provided high detection and sampling efficiency (,100%) and did not require staining of the cells for enumeration. [source] Androgen receptor function is modulated by the tissue-specific AR45 variantFEBS JOURNAL, Issue 1 2005Isabelle Ahrens-Fath A naturally occurring variant of the human androgen receptor (AR) named AR45 has been identified. It lacks the entire region encoded by exon 1 of the AR gene and is composed of the AR DNA-binding domain, hinge region and ligand-binding domain, preceded by a novel seven amino-acid long N-terminal extension. A survey of human tissues revealed that AR45 was expressed mainly in heart and skeletal muscle. In cotransfection experiments, AR45 inhibited AR function, an effect necessitating intact DNA- and ligand-binding properties. Overexpression of AR45 reduced the proliferation rate of the androgen-dependent LNCaP cells, in line with the repressive effects of AR45 on AR growth-promoting function. AR45 interacted with the AR N-terminal domain in two-hybrid assays, suggesting that AR inhibition was due to the formation of AR,AR45 heterodimers. Under conditions where the transcriptional coactivator TIF2 or the oncogene ,-catenin were overexpressed, AR45 stimulated androgen-dependent promoters in presence of dihydrotestosterone. AR45 activity was triggered additionally by the adrenal androgen androstenedione in presence of exogenous TIF2. Altogether, the data suggest an important role of AR45 in modulating AR function and add a novel level of complexity to the mode of action of androgens. [source] Caveolin-1 secreting LNCaP cells induce tumor growth of caveolin-1 negative LNCaP cells in vivoINTERNATIONAL JOURNAL OF CANCER, Issue 3 2008René Bartz Abstract Caveolin-1 (Cav-1) was originally identified as a structural protein of caveolae, which is a plasma membrane domain that regulates a variety of signaling pathways involved in cell growth and migration. Here, we show that expression of Cav-1 in the Cav-1-deficient human prostate cancer cell line LNCaP both stimulates cell proliferation and promotes tumor growth in nude mice. Unexpectedly, Cav-1 expressing LNCaP (LNCaPCav-1) cells injected into one side of a nude mouse promoted tumor growth of Cav-1 negative LNCaP cells injected on the contralateral side of the same animal. The LNCaP tumors were positive for Cav-1, however, this signal was not caused by migrated LNCaPCav-1 cells, but we show that this Cav-1 was secreted by the LNCaPCav-1 tumors. We demonstrate that conditioned media from LNCaPCav-1 cells contained Cav-1 that was associated with a lipoprotein particle ranging in size from 15 to 30 nm and a density similar to high density lipoprotein particle. These results suggest that LNCaPCav-1 cells secreting Cav-1 particle produce an endocrine factor that stimulates tumor growth. © 2007 Wiley-Liss, Inc. [source] ERK inhibitor PD98059 enhances docetaxel-induced apoptosis of androgen-independent human prostate cancer cellsINTERNATIONAL JOURNAL OF CANCER, Issue 3 2003Stanislav Zelivianski Abstract Anticancer drugs docetaxel and vinorelbine suppress cell growth by altering microtubule assembly and activating the proapoptotic signal pathway. Vinorelbine and docetaxel have been approved for treating several advanced cancers. However, their efficacy in the management of advanced hormone-refractory prostate cancer remains to be clarified. Microtubule damage by some anticancer drugs can activate the ERK survival pathway, which conversely compromises chemotherapeutic efficacy. We analyzed the effect of ERK inhibitors PD98059 and U0126 on vinorelbine- and docetaxel-induced cell growth suppression of androgen-independent prostate cancer cells. In androgen-independent C-81 LNCaP cells, inhibition of ERK by PD98059, but not U0126, plus docetaxel resulted in enhanced growth suppression by an additional 20% compared to the sum of each agent alone (p < 0.02). The combination treatment of docetaxel plus PD98059 also increased cellular apoptosis, which was in part due to the inactivation of Bcl-2 by increasing phosphorylated Bcl-2 by more than 6-fold and Bax expression by 3-fold over each agent alone. At these dosages, docetaxel alone caused only marginal phosphorylation of Bcl-2 (10%). Docetaxel plus U0126 had only 20% added effect on Bcl-2 phosphorylation compared to docetaxel alone. Nevertheless, both U0126 and PD98059 exhibited an enhanced effect on docetaxel-induced growth suppression in PC-3 cells. No enhanced effect was observed for vinorelbine plus PD98059 or U0126. Thus, the combination therapy of docetaxel plus PD98059 may represent a new anticancer strategy, requiring lower drug dosages compared to docetaxel monotherapy. This may lower the cytotoxicity and enhance tumor suppression in vivo. This finding of a combination effect could be of potential clinical importance in treating hormone-refractory prostate cancer. © 2003 Wiley-Liss, Inc. [source] Establishment and characterization of androgen-independent human prostate cancer cell lines, LN-REC4 and LNCaP-SF, from LNCaPINTERNATIONAL JOURNAL OF UROLOGY, Issue 3 2007Yoichi Iwasa Aim: To investigate the mechanisms of androgen-independent growth in prostate cancer (PCa), we established two PCa cell lines, LN-REC4 and LNCaP-SF, from the androgen-dependent PCa cell line, LNCaP. Materials and methods: LN-Pre and LN-REC4 cells were generated from LNCaP tumors grown on intact and castrated severe combined immunodeficient (SCID) mouse, respectively. After we cultured LNCaP cells under a steroid-free conditions for 6 months in vitro, LNCaP-SF cells were established. To show the character of LN-REC4 and LNCaP-SF cells, androgen sensitivity was investigated through examination of growth rate, and prostate-specific antigen (PSA), androgen receptor (AR), p21, p27, and cyclin D1 expression were examined by reverse transcription-polymerase chain reaction (RT-PCR). Angiogenesis assay in vitro was carried out using conditioned medium. To examine the expression level of vascular endothelial growth factor (VEGF), RT-PCR and enzyme-linked immunosorbent assay were also done. Results and conclusions: LN-REC4 cells proliferated better than LNCaP cells in castrated mice and did well irrespective of castration, although responsiveness for androgen of LN-REC4 cells attenuated less than that of LNCaP cells in vitro. LNCaP-SF cells in castrated mice proliferated more rapidly than in normal mice. The PSA expression in LNCaP-SF cells was still induced by androgen. Expression of AR, p21, p27 and cyclin D1 were not changed in LN-REC4 and LNCaP-SF cells. Angiogenesis assay showed that both cells stimulated angiogenesis. LN-REC4 induced VEGF more than LNCaP and LN-Pre cells. However, expression of VEGF per cell in LNCaP-SF was lower than LNCaP cells, suggesting that other factors might be involved in angiogenesis. These cell lines might be a useful tool for researching androgen-independent growth and treatments of recurred PCa. [source] Importance of C16 ceramide accumulation during apoptosis in prostate cancer cellsINTERNATIONAL JOURNAL OF UROLOGY, Issue 2 2006MASATOSHI ETO Aim:, Adenocarcinoma of the prostate is one of the most frequently diagnosed non-cutaneous cancers and the second leading cause of cancer-related deaths among men in the United States. To fully understand the role of ceramide during apoptosis induced by androgen ablation, we modified the levels of intracellular ceramide by pharmacological agents as well as through serum deprivation in androgen-dependent and independent cell lines. Methods:, Ceramide levels were modified using N-oleoylethanolamine (NOE), sphingosine-1-phosphate (S1P) as well as through serum deprivation, in LNCaP, DU145 and PC-3 prostate cancer cells. Various methods including nonyl acridine orange staining, propidium iodide staining/cell cycle analysis and lipid analysis were utilized. Results:, Our results demonstrate that the inhibition of acid ceramidase by NOE enhances the intracellular ceramide levels induced by androgen ablation in androgen-dependent LNCaP cells, and is accompanied by an increase in apoptotic cells. Sphingosine 1-phosphate had no effect in rescuing LNCaP cells from apoptosis induced by androgen ablation. Our results also show that serum deprivation causes intracellular ceramide accumulation and apoptosis in androgen-independent prostate cancer cells. Conclusions:, Our studies indicate that the increase in intracellular ceramide itself, but not the balance between ceramide and S1P, determines whether LNCaP cells undergo apoptosis. Our results also show that the increase in intracellular ceramide strongly correlates with apoptosis induced by serum deprivation even in androgen-independent prostate cancer cell lines. [source] Genistein induces cell growth inhibition in prostate cancer through the suppression of telomerase activityINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2005HIDEKI OUCHI Abstract Aim:, To clarify the mechanism of the anticancer effect of genistein, we examined the effect of genistein on telomerase activity in prostate cancer cells. We hypothesized that genistein may exert its anticancer effect by modifying telomerase activity in prostate cancer cells. Methods:, Prostate cancer (LNCaP) cells were cultured with genistein and the number of viable cells was counted. Growth medium was also collected to measure prostate-specific antigen (PSA) concentration. Polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay and reverse transcriptase (RT)-PCR analysis were performed to investigate telomerase activity and the expression of human telomerase reverse transcriptase (hTERT), c-myc and p21 mRNA. To examine the possibility that hTERT transcriptional activity is modulated by genistein, transient cell transfection studies were performed by using luciferase reporter assay. Telomere repeat amplification protocol (TRAP) assay and PCR analysis of hTERT were performed in androgen independent cells, DU-145. Results:, Cell growth of LNCaP was inhibited by genistein and PSA secretion was similarly reduced. In TRAP assay, the telomerase activity of LNCaP cells was reduced by genistein. Reverse transcriptase-PCR analysis revealed that the expression of hTERT and c-myc mRNA was down-regulated by genistein, whereas p21 mRNA increased in response to genistein. Luciferase reporter assay revealed that genistein reduced the transcriptional activity of hTERT. In DU-145 cells, telomerase activity and the expression of hTERT mRNA were also reduced by genistein. Conclusion:, The current study elucidated the molecular mechanism of cell growth inhibition by genistein. The antiproliferative effects of genistein seem to be exerted on the hTERT transcriptional activity via different molecular pathways. [source] Comparison of two in vivo models for prostate cancer: Orthotopic and intratesticular inoculation of LNCaP or PC-3 cellsINTERNATIONAL JOURNAL OF UROLOGY, Issue 12 2004KIYOSHI KOSHIDA Abstract, Background:, The critical events in the clinical course of prostate cancer are the occurrence of metastasis and the induction of the hormone-refractory status of the disease. In order to investigate the factors responsible for these events, we need appropriate in vivo models. Materials and methods:, Orthotopic and intratesticular models were created by the injection of LNCaP cells or PC-3 cells into the prostate or testis of severe combined immunodeficient mice. Results:, LNCaP cells in the intratesticular model showed a higher incidence of tumor formation and lymph node metastasis when compared with those in the orthotopic model, while PC-3 cells were highly tumorigenic and metastastic in both models. A high concentration of androgens might play a role in tumor aggressiveness of LNCaP cells, given that enhanced mRNA expressions of integrin ,V and vascular endothelial growth factor was induced by dehydrotestosterone administration in vitro. The high expression of metastasis-related genes, including the urokinase plasminogen activator system, metalloproteinases and vascular endothelial growth factor-C, might be attributed to the high metastatic potential in both models. Interestingly, testicular xenografts of LNCaP cells were able to survive on the subcutis back of castrated male mice as well female mice. Conclusions:, Intratesticular models of prostate cancer appear to be suitable for studying the mechanisms of metastasis and for evaluating various treatment strategies. [source] Suicide gene therapy on LNCaP human prostate cancer cellsINTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2001Ichiro Yoshimura Two types of plasmid vectors with the HSV-TK gene were constructed. A constitutive chicken ,-actin promoter drove one and a prostate-specific antigen (PSA) promoter drove the other. Similarly, a pair of plasmids with the CD gene under a cytomegalovirus (CMV) promoter and the PSA promoter was also constructed. LNCaP cells were transfected in vitro with either or both of those plasmids using a cationic lipid reagent. Transfected cells were treated with GCV and/or 5-FC. The percentage of viable LNCaP cells 7 days after treatment with HSV-TK/GCV or CD/5-FC under a constitutive promoter was 40% and 41% of controls, respectively. The cell viability when two suicide genes were combined was 23%. The cell viabilities after four days with PSA promoter-HSV-TK vectors, CD vectors and a combination of both were 79%, 88% and 88%, respectively. Suicide gene therapy using either HSV-TK/GCV, CD/5-FC, or both, was effective in the LNCaP model. An additive effect was observed when the two suicide genes were used together. The PSA promoter did not seem to be effective enough to elicit cytotoxicity under the experimental conditions used here. [source] RUNX1 (AML-1) and RUNX2 (AML-3) cooperate with prostate-derived Ets factor to activate transcription from the PSA upstream regulatory regionJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006Marcie Fowler Abstract The RUNX transcription factors (RUNX1, RUNX2, and RUNX3) play essential roles in hematopoiesis and skeletal development. Consistent with these roles in differentiation and cell cycle, the activity of both RUNX1 and RUNX3 is perturbed in cancer. To determine a role for the RUNX factors in prostate biology, we investigated the expression of RUNX factors in prostate epithelial cell lines and normal prostate tissue. RUNX1, RUNX2, and RUNX3 were expressed in both normal prostate tissue and an immortalized, non-transformed cell line. We found that prostate cancer-derived cell lines expressed RUNX1 and RUNX2, but not RUNX3. Next, we sought to identify prostate-specific genes whose expression could be regulated by RUNX proteins. Four consensus RUNX sites are located within the prostate-specific antigen (PSA) regulatory region. Chromatin immunoprecipitation (ChIP) analysis showed that RUNX1 is specifically bound to the PSA regulatory region in LNCaP cells. RUNX1 and RUNX2 activated the PSA regulatory region alone or cooperatively with prostate- derived ETS factor (PDEF) and RUNX1 physically associated with PDEF. Taken together, our results suggest that RUNX factors participate in prostate epithelial cell function and cooperate with an Ets transcription factor to regulate PSA gene expression. J. Cell. Biochem. © 2005 Wiley-Liss, Inc. [source] Melatonin induces apoptotic death in LNCaP cells via p38 and JNK pathways: therapeutic implications for prostate cancerJOURNAL OF PINEAL RESEARCH, Issue 1 2009Seong Soo Joo Abstract:, Apoptosis, a form of cell death, is a fundamental process for the development and maintenance of multicellular organisms that promotes the removal of damaged, senescent or unwanted cells. Induction of cancer cell apoptosis is an important strategy of anticancer therapy. In this study, we examined if melatonin, the main secretory product of the pineal gland, inhibited the growth of prostate cancer cells (LNCaP) and promoted apoptosis via mitogen-activated protein kinases (MAPKs), which are closely associated with apoptosis and survival. Melatonin treatment significantly inhibited the growth of LNCaP cells in a dose- and time-dependent manner. It clearly induced both an early stage of apoptosis (propidium iodide,, FITC Annexin-V+) and a late apoptosis/secondary necrosis (propidium iodide+ and FITC Annexin-V+), which indicated induction of serial stages of apoptosis in cells. Moreover, melatonin markedly activated c-JUN N-terminal kinase (JNK) and p38 kinase, whereas extracellular signal-regulated kinase (ERK) was not responsive to melatonin. Treatment with MAPK inhibitors, PD98059 (ERK inhibitor), SP600125 (JNK inhibitor) and SB202190 (p38 inhibitor), confirmed that melatonin-induced apoptosis was JNK- and p38-dependent, but ERK-independent. In the presence of PD98059, caspase-3 activity increased, while levels of Bax/cytochrome c (Cyt c) and Bcl-2 decreased. These effects were opposite to those observed with SP600125 and SB202190 treatments. Together, these results strongly suggest that JNK and p38 activation directly participate in apoptosis induced by melatonin. Thus, melatonin may be of promise for anti-prostate cancer strategies. [source] Inositol hexaphosphate downregulates both constitutive and ligand-induced mitogenic and cell survival signaling, and causes caspase-mediated apoptotic death of human prostate carcinoma PC-3 cells,MOLECULAR CARCINOGENESIS, Issue 1 2010Mallikarjuna Gu Abstract Constitutively active mitogenic and prosurvival signaling cascades due to aberrant expression and interaction of growth factors and their receptors are well documented in human prostate cancer (PCa). Epidermal growth factor (EGF) and insulin-like growth factor-1 (IGF-1) are potent mitogens that regulate proliferation and survival of PCa cells via autocrine and paracrine loops involving both mitogen-activated protein kinase (MAPK)- and Akt-mediated signaling. Accordingly, here we assessed the effect of inositol hexaphosphate (IP6) on constitutive and ligand (EGF and IGF-1)-induced biological responses and associated signaling cascades in advanced and androgen-independent human PCa PC-3 cells. Treatment of PC-3 cells with 2,mM IP6 strongly inhibited both growth and proliferation and decreased cell viability; similar effects were also observed in other human PCa DU145 and LNCaP cells. IP6 also caused a strong apoptotic death of PC-3 cells together with caspase 3 and PARP cleavage. Mechanistic studies showed that biological effects of IP6 were associated with inhibition of both constitutive and ligand-induced Akt phosphorylation together with a decrease in total Akt levels, but a differential inhibitory effect on MAPKs extra cellular signal-regulated kinase 1/2 (ERK1/2), c- Jun N-terminal protein kinase (JNK1/2), and p38 under constitutive and ligand-activated conditions. Under similar condition, IP6 also inhibited AP-1 DNA-binding activity and decreased nuclear levels of both phospho and total c-Fos and c- Jun. Together, these findings for the first time establish IP6 efficacy in inhibiting aberrant EGF receptor (EGFR) or IGF-1 receptor (IGF-1R) pathway-mediated sustained growth promoting and survival signaling cascades in advanced and androgen-independent human PCa PC-3 cells, which might have translational implications in advanced human PCa control and management. © 2009 Wiley-Liss, Inc. [source] PKC-mediated secretion of death factors in LNCaP prostate cancer cells is regulated by androgensMOLECULAR CARCINOGENESIS, Issue 3 2009Liqing Xiao Abstract Activation of PKC, in androgen-dependent LNCaP prostate cancer cells leads to apoptosis via the activation of p38 MAPK and JNK cascades. We have recently shown that treatment of LNCaP cells with phorbol 12-myristate 13-acetate (PMA) leads to a PKC,-mediated autocrine release of death factors, including the cytokines TNF, and TRAIL, and that conditioned medium (CM) collected from PMA-treated LNCaP cells promotes the activation of the extrinsic apoptotic cascade. Interfering with this autocrine loop either at the level of factor release or death receptor activation/signaling markedly impaired the PMA apoptotic response. In the present study we show that this PKC,-dependent autocrine mechanism is greatly influenced by androgens. Indeed, upon androgen depletion, which down-regulates PKC, expression, TNF, and TRAIL mRNA induction and release by PMA are significantly diminished, resulting in a reduced apoptogenic activity of the CM and an impaired ability of the CM to activate p38 MAPK and JNK. These effects can be rescued by addition of the synthetic androgen R1881. Furthermore, RNAi depletion of the androgen-receptor (AR) from LNCaP cells equally impaired PMA responses, suggesting that PKC-mediated induction of death factor secretion and apoptosis in LNCaP prostate cancer cells are highly sensitive to hormonal control. © 2008 Wiley-Liss, Inc. [source] Prostaglandin E2 induces vascular endothelial growth factor secretion in prostate cancer cells through EP2 receptor-mediated cAMP pathwayMOLECULAR CARCINOGENESIS, Issue 11 2007Xingya Wang Abstract Prostaglandin E2 (PGE2) has been shown to induce expression of vascular endothelial growth factor (VEGF) and other signaling molecules in several cancers. PGE2 elicits its functions though four G-protein coupled membrane receptors (EP1,4). In this study, we investigated the role of EP receptors in PGE2 -induced molecular events in prostate cancer cells. qRT-PCR analysis revealed that PC-3 cells express a substantially higher level of EP2 and moderately higher EP4 than DU145 and LNCaP cells. LNCaP cells had virtually no detectable EP2 mRNA. EP1 and EP3 mRNAs were not detected in these cells. Treatment of prostate cancer cells with PGE2 (1 nM,10 µM) increased both VEGF secretion and cyclic adenosine monophosphate (cAMP) production. Levels of induction in PC-3 cells were greater than in DU145 and LNCaP cells. The selective EP2 agonist CAY10399 also significantly increased VEGF secretion and cAMP production in PC-3 cells, but not in DU145 and LNCaP cells. Moreover, PGE2 and CAY10399 increased mitogen activated protein kinase/extracellular signal regulated kinase (MAPK/Erk) and Akt phosphorylation in PC-3 and DU145 cells, but not in LNCaP cells. However, neither the MAPK/Erk inhibitor U0126 nor the PI3K/Akt inhibitor LY294002 abolished PGE2 -induced VEGF secretion in PC-3 cells. We further demonstrated that the adenylate cyclase activator forskolin and the cAMP anologue 8-bromo-cAMP mimicked the effects of PGE2 on VEGF secretion in PC-3 cells. Meanwhile, the adenylate cyclase inhibitor 2,5,-dideoxyadenosine, at concentrations that inhibited PGE2 -induced cAMP, significantly blocked PGE2 -induced VEGF secretion in PC-3 cells. We conclude that PGE2 -induced VEGF secretion in prostate cancer cells is mediated through EP2-, and possibly EP4-, dependent cAMP signaling pathways. © 2007 Wiley-Liss, Inc. [source] Chromatin changes on the GSTP1 promoter associated with its inactivation in prostate cancerMOLECULAR CARCINOGENESIS, Issue 10 2007Steven T. Okino Abstract Glutathione- S -transferases (GSTs) are metabolic enzymes that help detoxify and eliminate harmful chemicals. In prostate tumors, expression of GST , (encoded by GSTP1) is frequently lost because of promoter hypermethylation. Here we analyze the native GSTP1 promoter in cancerous and noncancerous human prostate cells to identify structural features associated with its cancer-related transcriptional silencing. We find that in noncancerous prostate cells (RWPE-1 and PWR-1E) GSTP1 is constitutively expressed, not methylated, highly accessible, bound by transcription factors and associated with histones with activating modifications (histone H3 methylated at lysine 4 and acetylated histones H3 and H4). In contrast, in cancerous prostate cells (LNCaP) GSTP1 is not expressed, extensively methylated, inaccessible, lacks bound transcription factors and is not associated with histones with activating modifications. We do not detect significant levels of histones with repressive modifications (histone H3 methylated at lysine 9 or 27) on GSTP1 in any cell line indicating that they are not associated with cancer-related GSTP1 silencing. Treatment of LNCaP cells with 5-azacytidine restores activating histone modifications on GSTP1 and reactivates transcription. We conclude that, in the process of prostate carcinogenesis, activating histone modifications on GSTP1 are lost and the DNA becomes methylated and inaccessible resulting in transcriptional silencing. © 2007 Wiley-Liss, Inc. [source] Genistein affects androgen-responsive genes through both androgen- and estrogen-induced signaling pathways,MOLECULAR CARCINOGENESIS, Issue 1 2006Yoko Takahashi Abstract This study examined the mechanisms by which the prostate cancer chemopreventive agent genistein modulates gene expression in LNCaP human prostate cancer cells. Expression of androgen- and estrogen-regulated genes was measured in LNCaP cells cultured in the presence or absence of hormonal stimulation and the presence or absence of genistein. Genistein strongly suppressed basal expression of androgen-responsive gene (ARG) mRNAs, including prostate-specific antigen (PSA) and Ste20-related proline-alanine-rich kinase (SPAK). However, genistein had little or no effect on basal expression of two other ARGs, ,2 -microglobulin (B2M) or selenoprotein P (SEPP1). Culturing LNCaP cells in the presence of the synthetic androgen R1881-induced increases in PSA, SPAK, B2M, and SEPP1 mRNA levels. The R1881-induced expression of these genes was uniformly blocked by genistein. For PSA and SPAK, genistein also blocked or downregulated 17,-estradiol-induced increases in mRNA expression. These results indicate that genistein selectively alters expression of ARG mRNAs in LNCaP cells through modulation of both androgen- and estrogen-induced signaling pathways. Published 2005 Wiley-Liss, Inc. [source] Role of mitogen-activated protein kinases in phenethyl isothiocyanate-induced apoptosis in human prostate cancer cellsMOLECULAR CARCINOGENESIS, Issue 3 2005Dong Xiao Abstract The present study was undertaken to examine the role of mitogen-activated protein kinases (MAPKs) in apoptosis induction by phenethyl isothiocyanate (PEITC), a cruciferous vegetable-derived cancer chemopreventive agent, with DU145 and LNCaP human prostate cancer cells as a model. The MAPK family of serine/threonine kinases, including extracellular signal-regulated kinase1/2 (ERK1/2), c- jun N-terminal kinase1/2/3 (JNK1/2/3), and p38 MAPK play an important role in cell proliferation and apoptosis in response to different stimuli. Exposure of DU145 and LNCaP cells to growth suppressive concentrations of PEITC resulted in activation of ERK1/2 and JNKs, but not p38 MAPK, in both cell lines. In DU145 cells, the apoptosis induction by PEITC was statistically significantly attenuated by pharmacological inhibition of JNKs with SP600125. Adenovirus-mediated overexpression of Flag-tagged JNK binding domain (JBD) of JNK-interacting protein-1 (JIP-1), an inhibitor of JNK, also inhibited PEITC-induced apoptosis in DU145 cells. On the other hand, inhibition of ERK1/2 activation with MEK1 inhibitor PD98059 failed to offer protection against PEITC-induced apoptosis in DU145 cells. In LNCaP cells, the PEITC-induced cell death was not affected by either pretreatment with PD98059 or SP600125 or overexpression of JBD of JIP-1. These results indicate that involvement of MAPKs in apoptosis induction by PEITC in human prostate cancer cells is cell line-specific. © 2005 Wiley-Liss, Inc. [source] Novel Methyl Helianthrones as Photosensitizers: Synthesis and Biological Evaluation,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Shai Rahimipour ABSTRACT A combination of light, oxygen and a photosensitizer is used to induce death of cancer cells by photodynamic therapy. In this study, we have synthesized several new methyl helianthrone derivatives and compared their phototoxicity with that of hypericin. In contrast to hypericin, methyl helianthrones are soluble in aqueous solutions and have a broad range of light absorbance, which allows the use of polychromatic light. Structural modifications of methyl helianthrone demonstrated that substitution of hydrogen atoms of methyl helianthrone at Positions 2 and 5 with Br atoms or methylation of its phenolic hydroxyls, significantly increases the corresponding singlet oxygen quantum yield and their phototoxicity toward ,T3-1, M2R and LNCaP cells. The phototoxicity of some of these compounds was similar to that of hypericin. Methyl helianthrones, like hypericin, accumulated mainly in the perinuclear region as evident by confocal microscopy. Irradiation of cells pretreated with methyl helianthrone derivatives generates intracellular reactive oxygen species and lipid free radicals, as shown by a fluorescentic probe and electron paramagnetic resonance methods, respectively. The phototoxicity of these methyl helianthrones as well as their ability to oxidize membrane lipids were significantly decreased on addition of specific Type-II inhibitors, suggesting the involvement of singlet oxygen as the main oxidant. [source] Quantitative profiling of LNCaP prostate cancer cells using isotope-coded affinity tags and mass spectrometryPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2004Katie L. Meehan Abstract Androgens are involved in the pathogenesis of diseases including adenocarcinoma of the prostate. These hormones are important for growth, maintenance, and integrity of structure and function of the prostate. Androgen-deprivation is currently the only effective systemic therapy for prostate cancer but the effects of androgens on the proteome are still poorly described. Here we quantitatively profile changes in the proteome of LNCaP human prostate cancer cells in response to androgen using the newly developed isotope-coded affinity tag (ICAT) labeling and two-dimensional liquid chromatography-tandem mass spectroscopy (2-D LC-MS/MS). ICAT enables the concurrent identification and comparative quantitative analysis of proteins present in various biological samples including human cell and tissue extracts. Quantification and identification of 139 proteins in complex protein mixtures obtained from androgen-stimulated and unstimulated LNCaP cells were achieved. Changes in levels of 77 proteins in response to androgens were detected. Some of these proteins have been previously reported to be regulated by androgens and include spermine synthase, fatty acid synthase and calreticulin precursor. A large number of proteins that have not been previously reported to be expressed in prostate cells were also quantitatively identified. Examples of these include members of the dual specificity protein phosphatase subfamily, "similar" to hypothetical protein DKFZp434B0328.1, "similar" to 14-3-3 protein zeta and "similar" to hypothetical protein 458, components of the actin cytoskeleton and a range of unknown/uncharacterized proteins. This catalogue of proteins provides an overview of the proteome of prostate cancer cells and the global changes that occur in response to androgens. [source] The developmental expression profile of PAX2 in the murine prostateTHE PROSTATE, Issue 6 2010Qian Chen Abstract BACKGROUND Nine transcription factors comprise the PAX gene family that regulate organogenesis. The urogenital system of PAX2 null male mice fails to develop properly. PAX2 is overexpressed in PC3 cells. Therefore, PAX2 is implicated in both prostate organogenesis and cancer. However, the expression pattern/profile of PAX2 in the prostate is unknown. METHODS PAX2/5/8 expression was surveyed in E16.5 male urogenital sinus (UGS) by RT-PCR. Prostate samples from 10 developmental stages in C3H male mice were used in quantitative reverse-transcript PCR (Q-PCR) and Western blotting (WB). RT-PCR and WB measured PAX2 expression in prostatic lobes or UGS layers, to identify local-regional expression patterns. Cytoplasmic versus nuclear expression was examined by WB. A castration series in adult C3H male mice and R1881 treatment in serum-free LNCaP cells examined androgen control of PAX2. RESULTS PAX2 mRNA levels are higher in early developmental stages as compared to postpubertal prostates. RT-PCR and/or WB indicated a dorsal epithelial,nuclear localization of PAX2. PAX2 mRNA and protein increase postcastration. R1881 decreases expression of PAX2 mRNA in LNCaP cells as compared to controls. CONCLUSIONS The expression profile of PAX2 indicates that it may regulate early, androgen-independent stages of murine prostate development, particularly for dorsally derived prostate glands. PAX2 expression appears to be associated with a dorsally localized epithelial cell population that is castration insensitive and retains proliferative and differentiative potential. Such a population of cells may represent a subset of stem-like cells having some characteristics in common with castrate-resistant prostate cancer cells. Prostate 70: 654,665, 2010. © 2009 Wiley-Liss, Inc. [source] Arachidonic acid activation of intratumoral steroid synthesis during prostate cancer progression to castration resistanceTHE PROSTATE, Issue 3 2010Jennifer A. Locke Abstract BACKGROUND De novo androgen synthesis and subsequent androgen receptor (AR) activation has recently been shown to contribute to castration-resistant prostate cancer (CRPC) progression. Herein we provide evidence that fatty acids (FA) can trigger androgen synthesis within steroid starved prostate cancer (CaP) tumor cells. METHODS Tumoral FA and steroid levels were assessed by GC,MS and LC,MS, respectively. Profiles of genes and proteins involved in FA activation of steroidogenesis were assessed by fluorescence microscopy, immunohistochemistry, microarray expression profiling and Western blot analysis. RESULTS In human CaP tissues the levels of proteins responsible for FA activation of steroid synthesis were observed to be altered during progression to CRPC. Further investigating this mechanism in LNCaP cells, we demonstrate that specific FA, arachidonic acid, is synthesized in an androgen-dependent and AR-mediated manner. Arachidonic acid is known to induce steroidogenic acute regulatory protein (StAR) in steroidogenic cells. When bound to hormone sensitive lipase (HSL), StAR shuttles free cholesterol into the mitochondria for downstream conversion into androgens. We show that arachidonic acid induces androgen production in steroid starved LNCaP cells coincidently in the same conditions that HSL and StAR are predominantly localized in the mitochondria. Furthermore, their activities are verified by a functional increase in mitochondrial uptake of cholesterol in this steroid starved environment. CONCLUSIONS We propose that this characterized arachidonic acid induced steroidogenesis mechanism significantly contributes to the activation of AR in CRPC progression and therefore recommend that fatty acid pathways be targeted therapeutically in progressing CaP. Prostate 70: 239,251, 2010. © 2009 Wiley-Liss, Inc. [source] Regulation of PSA secretion and survival signaling by calcium-independent phopholipase A2, in prostate cancer cellsTHE PROSTATE, Issue 12 2009Thomas M. Nicotera Abstract BACKGROUND Serum prostate specific antigen (PSA) levels in prostate cancer patients serve as a useful biomarker for diagnosing and monitoring prostate cancer. Recently, secreted PSA has been characterized as an autocrine survival factor through activation of Akt and induction of AR. In the normal prostate, PSA is secreted in the lumen of prostatic ducts to lyse proteins in the seminal coagulum. METHODS However, the mechanism for constitutive PSA secretion from benign prostate and its transport across the prostate-blood barrier into serum are unknown. Regulation of peptide secretion by iPLA2 -, has been reported in non-prostatic tissue and in prostate tissue iPLA2 -, is reported to be under androgen regulation. We investigated whether iPLA2 plays a role for in PSA secretion by comparing iPLA2 activity and expression in normal prostate epithelial RWPE-1 cells and in LNCaP prostate cancer cells. Expression of the two active iPLA2 -, mRNA splice variants, LH-iPLA2 and SH-iPLA2, were increased and the inhibitory ankyrin-iPLA2 isoform was markedly reduced in LNCaP cells as compared to normal prostate epithelial RWPE-1 cells. RESULTS These changes are consistent with a higher enzymatic activity in LNCaP cells. The iPLA2 -,-specific inhibitor BEL inhibited PSA secretion and induced apoptosis in LNCaP cells. iPLA2 knockdown using SiRNA inhibited PSA secretion, downregulated AR and induced apoptosis. Exogenous PSA suppressed BEL-induced apoptosis and neutralizing anti-PSA antibody blocked the survival effect of PSA. CONCLUSIONS These data indicate that iPLA2 -, participates in regulating PSA secretion and supports the concept that secreted PSA provides an autocrine survival function in LNCaP cells. Prostate 69:1270,1280, 2009. © 2009 Wiley-Liss, Inc. [source] The prostatic environment suppresses growth of androgen-independent prostate cancer xenografts: An effect influenced by testosteroneTHE PROSTATE, Issue 11 2009Karin Jennbacken Abstract BACKGROUND Interactions between prostate cancer cells and their surrounding stroma play an important role in the growth and maintenance of prostate tumors. To elucidate this further, we investigated how growth of androgen-dependent (AD) LNCaP and androgen-independent (AI) LNCaP-19 prostate tumors was affected by different microenvironments and androgen levels. METHODS Tumor cells were implanted subcutaneously and orthotopically in intact and castrated immunodeficient mice. Orthotopic tumor growth was followed by magnetic resonance imaging (MRI). Gene expression in the tumors was evaluated by means of microarray analysis and microvessel density (MVD) was analyzed using immunohistochemistry. RESULTS The results showed that LNCaP-19 tumors grew more rapidly at the subcutaneous site than in the prostate, where tumors were obviously inhibited. Castration of the mice did not affect ectopic tumors but did result in increased tumor growth in the prostatic environment. This effect was reversed by testosterone treatment. In contrast to LNCaP-19, the LNCaP cells grew rapidly in the prostate and castration reduced tumor development. Gene expression analysis of LNCaP-19 tumors revealed an upregulation of genes, inhibiting tumor growth (including ADAMTS1, RGS2 and protocadherin 20) and a downregulation of genes, promoting cell adhesion and metastasis (including N-cadherin and NRCAM) in the slow-growing orthotopic tumors from intact mice. CONCLUSIONS The results show that the prostatic environment has a varying impact on AD and AI tumor xenografts. Data indicate that the androgen-stimulated prostatic environment limits growth of orthotopic AI tumors through induction of genes that inhibit tumor growth and suppression of genes that promote cell adhesion and metastasis. Prostate 69:1164,1175, 2009. © 2009 Wiley-Liss, Inc. [source] Regulation of cell survival by resveratrol involves inhibition of NF,B-regulated gene expression in prostate cancer cellsTHE PROSTATE, Issue 10 2009Dixan A. Benitez Abstract BACKGROUND Polyphenols have been proposed as antitumoral agents. We have shown that resveratrol (RES) induced cell cycle arrest and promoted apoptosis in prostate cancer cells by inhibition of the PI3K pathway. The RES effects on NF,B activity in LNCaP cells (inducible NF,B), and PC-3 cells (constitutive NF,B) are reported. METHODS Cells were treated with 1,150 µM of RES during 36 hr. NF,B subcellular localization was analyzed by western blot and immunofluorescence. I,B, was evaluated by immunoprecipitation followed by Western blot. Specific DNA binding of NF,B was determined by EMSA assays and NF,B-mediated transcriptional activity by transient transfection with a luciferase gene reporter system. RESULTS RES induced a dose-dependent cytoplasmic retention of NF,B mediated by I,B, in PC-3 cells but not in LNCaP. RES-induced inhibition of NF,B specific binding to DNA was more significant in PC-3 cells. NF,B-mediated transcriptional activity induced by EGF and TNF, were inhibited by RES in both cell lines. LY294002 mimicked RES effects on NF,B activity. CONCLUSION Antiproliferative and apoptotic effects of RES on human prostate cancer cells may be mediated by the inhibition of NF,B activity. This mechanism seems to be associated to RES-induced PI3K inhibition. RES could have therapeutic potential for prostate cancer treatment. Prostate 69:1045,1054, 2009. © 2009 Wiley-Liss, Inc. [source] In vitro targeted photodynamic therapy with a pyropheophorbide-a conjugated inhibitor of prostate-specific membrane antigenTHE PROSTATE, Issue 6 2009Tiancheng Liu Abstract BACKGROUND The lack of specific delivery of photosensitizers (PSs), represents a significant limitation of photodynamic therapy (PDT) of cancer. The biomarker prostate-specific membrane antigen (PSMA) has attracted considerable attention as a target for imaging and therapeutic applications for prostate cancer. Although recent efforts have been made to conjugate inhibitors of PSMA with imaging agents, there have been no reports on PS-conjugated PSMA inhibitors for targeted PDT of prostate cancer. The present study focuses on the use of a PSMA inhibitor-conjugate of pyropheophorbide-a (Ppa-conjugate 2) for targeted PDT to achieve apoptosis in PSMA+ LNCaP cells. METHODS Confocal laser scanning microscopy with a combination of nuclear staining and immunofluorescence methods were employed to monitor the specific imaging and PDT-mediated apoptotic effects on PSMA-positive LNCaP and PSMA-negative (PC-3) cells. RESULTS Our results demonstrated that PDT-mediated effects by Ppa-conjugate 2 were specific to LNCaP cells, but not PC-3 cells. Cell permeability was detected as early as 2 hr by HOE33342/PI double staining, becoming more intense by 4 hr. Evidence for the apoptotic caspase cascade being activated was based on the appearance of poly-ADP-ribose polymerase (PARP) p85 fragment. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay detected DNA fragmentation 16 hr post-PDT, confirming apoptotic events. CONCLUSIONS Cell permeability by HOE33342/PI double staining as well as PARP p85 fragment and TUNEL assays confirm cellular apoptosis in PSMA+ cells when treated with PS-inhibitor conjugate 2 and subsequently irradiated. It is expected that the PSMA targeting small-molecule of this conjugate can serve as a delivery vehicle for PDT and other therapeutic applications for prostate cancer. Prostate 69:585,594, 2009. © 2009 Wiley-Liss, Inc. [source] Gene profiling and pathway analysis of neuroendocrine transdifferentiated prostate cancer cellsTHE PROSTATE, Issue 1 2009Ryutaro Mori Abstract BACKGROUND Neuroendocrine (NE) cells are present in both normal prostate and prostate cancer. In addition, NE differentiation can be induced by various factors, such as IL-6, in vitro and in vivo. However, the mechanism of this differentiation and the role of NE cells in prostate cancer are not well understood. In this study, we evaluated the gene expression and analyzed the pathways in prostate cancer cells exposed to various NE differentiation inducing factors in vitro. METHODS Gene expression signatures between control LNCaP cells and each treatment induced NE cell line were compared using Affymetrix GeneChip with network and pathway analysis. RESULTS All treatments were able to transdifferentiate LNCaP cells into NE phenotype as shown by morphology changes and NE marker measurements. Of the 54,675 oligonucleotide-based probe sets in microarray, 44,975 were mapped into the Ingenuity Pathway Analysis database and were filtered according to the t -test P value. At P,<,0.002, the number of genes that were differentially expressed included 302 of the IL-6 treated cells, 201 of genistein, 233 of epinephrine, and 191 of the charcoal stripped serum ones. A pooled data approach also showed 346 differentially expressed genes at the same P value. Gene ontology analysis showed that cancer-related function had the highest significance. CONCLUSIONS Despite some overlap, each NE transdifferentiation inducing treatment was associated with a changed expression of a unique set of genes, and such gene profiling may help to elucidate the molecular mechanisms involved in NE transdifferentiation of prostate cancer cells. Prostate 69: 12,23, 2009. © 2008 Wiley,Liss, Inc. [source] NF-,B2/p52 enhances androgen-independent growth of human LNCaP cells via protection from apoptotic cell death and cell cycle arrest induced by androgen-deprivationTHE PROSTATE, Issue 16 2008Nagalakshmi Nadiminty Abstract PURPOSE Androgen-deprivation therapy only causes a temporary regression of prostate cancer, as all tumors will eventually progress to refractory to hormonal therapy after 1,3 years of treatment. The underlying mechanisms of prostate cancer androgen refractory progression are incompletely understood. In this study, we employed in vitro as well as in vivo models to examine the role of NF-,B2/p52 in prostate cancer growth and androgen independent progression. EXPERIMENTAL DESIGN The effects of NF-,B2/p52 on cell growth, androgen responsiveness, cell cycle and apoptosis were examined in androgen sensitive LNCaP cells. The effect of NF-,B2/p52 on tumor growth was examined in intact and castrated male mice. RESULTS Overexpression of NF-,B2/p52 enhances androgen-sensitive LNCaP human prostate cancer cell growth and clonogenic ability in androgen-deprived condition in vitro. NF-,B2/p52 induced androgen-independent growth is through protecting LNCaP cells from apoptotic cell death and cell cycle arrest induced by androgen-deprivation. In addition, NF-,B2/p52 stimulates Cyclin D1 expression and knock down of Cyclin D1 expression by siRNA abolished NF-,B2/p52-induced cell growth in vitro. Adenoviral mediated NF-,B2/p52 expression in LNCaP cells enhances tumor growth in intact male nude mice and induces tumor growth in castrated male nude mice, suggesting that overexpression of NF-,B2/p52 induces androgen-independent growth of androgen-sensitive LNCaP cells. CONCLUSIONS Overexpression of NF-,B2/p52 protects androgen sensitive LNCaP cells from apoptotic cell death and cell cycle arrest induced by androgen-deprivation. NF-,B2/p52 activation induces androgen-independent growth in vitro and in vivo. Prostate © 2008 Wiley-Liss, Inc. [source] Bicalutamide inhibits androgen-mediated adhesion of prostate cancer cells exposed to ionizing radiationTHE PROSTATE, Issue 16 2008Tao Wang Abstract Background Cell adhesion plays an important role in proliferation, metastasis, and tumor growth and may represent a potential vulnerability in treatment of prostate cancer patients. Bicalutamide (Casodex) has been used as an anti-androgen agent for prostate cancer patients during hormone ablation therapy. This study focuses on the effect of Bicalutamide on cell adhesion to fibronectin (FN) in prostate cancer cells. Methods Androgen,dependent LNCaP prostate cancer cells were stimulated with androgen before being irradiated with doses of 0, 5, 10, or 15 Gy. Cell adhesion to fibronectin was then measured to ascertain androgen's role in integrin mediated prostate cancer cell adhesion. Flow cytometry was used to analyze surface expression of integrin subtypes in LNCaP cells. Results LNCaP cell adhesion to FN was significantly increased by stimulation with androgen when treated with 10 or 15 Gy ionizing radiations but not at 0 or 5 Gy. This increase was inhibited by treatment with Bicalutamide. LNCaP cells exposed to high dose radiation showed an increased expression of ,V and ,1 integrins in response to androgen treatment while Bicalutamide abolished this effect. Conclusions Our data show that Bicalutamide inhibits the effect of androgen on cell adhesion to FN through changes of integrin subtypes in cells given high dose radiation. This suggests new molecular targets and possible treatment strategies for prostate cancer patients to improve the outcome during hormone ablation therapy and radiation therapy. Prostate © 2008 Wiley-Liss, Inc. [source] The potential role of purine-rich element binding protein (PUR) , as a novel treatment target for hormone-refractory prostate cancer,THE PROSTATE, Issue 10 2008Takahiro Inoue Abstract BACKGROUND Hormonal therapy for advanced prostate cancer is typically effective at first, but almost all men suffer refractory disease which often is life threatening. The nuclear matrix comprises not only of the structural elements of the nucleus, but is associated with many components of the molecular machinery. Our aim is to find novel targets for the treatment of hormone-refractory prostate cancer (HRPC) by focusing on the composition of the nuclear matrix proteins (NMPs). METHODS LN96 cells were established at our Institution after long-term culturing of LNCaP cells under androgen deprived conditions. The composition of NMPs of LNCaP cells and LN96 cells were analyzed by two-dimensional (2D) electrophoresis and spots differentially expressed were investigated by mass spectrometry for identification. Among the spots identified, we analyzed the potential functional role of the identified proteins in prostate cancer cells by establishing stable overexpressed cells. RESULTS We found that purine-rich element binding protein (PUR), was significantly repressed not only in NMPs but also in total protein and mRNA levels of LN96 cells in comparison to LNCaP cells under the same steroid deprived conditions. Moreover, PUR, was decreased in its expression both at the protein and mRNA levels in the androgen-independent prostate cancer cell lines, PC3 and DU145 in comparison to LNCaP cells. Stably overexpressing PUR, in PC3 and DU145 cells negatively regulates cell proliferation, resulting in decreases in PCNA expression. CONCLUSION Further dissection of the role of PUR, in cell growth regulation may reveal a novel target for HRPC. Prostate 68:1048,1056, 2008. © 2008 Wiley-Liss, Inc. [source] JunD mediates androgen-induced oxidative stress in androgen dependent LNCaP human prostate cancer cells,THE PROSTATE, Issue 9 2008Farideh Mehraein-Ghomi Abstract BACKGROUND Numerous and compelling evidence shows that high level of reactive oxygen species (ROS) plays a key role in prostate cancer occurrence, recurrence and progression. The molecular mechanism of ROS overproduction in the prostate gland, however, remains mostly unknown. Unique AP-1 transcription factor JunD has been shown to inhibit cell proliferation, promote differentiation and mediate stress responses in a variety of eukaryotic cells. We previously reported that androgen,androgen receptor induced ROS production in androgen-dependent LNCaP human prostate cancer cells is associated with increased JunD level/AP-1 transcriptional activity. METHODS LNCaP cells constitutively overexpressing a functionally inactive form of JunD (JunD,TA) or stably transfected with JunD siRNA (siJunD) to suppress JunD protein expression were established. Overexpression of JunD in LNCaP cells using transient transfection method was applied to assess the induction of ROS production in LNCaP cells. DCF assay was used to measure the ROS concentrations in the transfected as well as non-transfected control cells. RT-PCR and Western blot analyses were used to confirm silencing or overexpression of JunD in the transfected cells. RESULTS In the absence of androgen, LNCaP cells transiently transfected with a JunD overexpressing vector have relatively enhanced cellular ROS levels as compared to LNCaP cells transfected with a vector control. LNCaP cells that fail to express functional JunD (JunD,TA or siJunD) do not exhibit any increase in ROS production in response to androgen. CONCLUSION Based on these data, we conclude that JunD is an essential mediator of the androgen-induced increase in ROS levels in LNCaP cells. Prostate 68:924,934, 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||