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Human Prostate Cancer Cells (human + prostate_cancer_cell)
Kinds of Human Prostate Cancer Cells Terms modified by Human Prostate Cancer Cells Selected AbstractsBcl-2 mediated modulation of vascularization in prostate cancer xenografts,THE PROSTATE, Issue 5 2009Yoshihisa Sakai Abstract PURPOSE We previously demonstrated that Bcl-2 overexpression enhances the radiation resistance of PC-3 human prostate cancer cells and xenografts by inhibiting apoptosis, increasing proliferation, and promoting angiogenesis. To further elucidate the relationship between Bcl-2 expression and the angiogenic potential of PC-3-Bcl-2 cells, tumorigenicity, angiogenesis, and lymphangiogenesis were evaluated and compared in a Bcl-2 overexpressing clone in vitro and in vivo. EXPERIMENTAL DESIGN Human prostate cancer cells over expressing Bcl-2 were studied in vitro and in vivo to determine the angiogenic and lymphangiogenic properties of these cells. RESULTS Increased Bcl-2 expression enhanced the tumorigenicity of prostate cancer xenografts. It also enhanced the expression and secretion of key angiogenic and lymphangiogenic factors that stimulated the synthesis of CD31-positive blood vessels and LYVE-1 positive lymphatics. Specifically, the increased angiogenic and lymphangiogenic potential correlated with increased serum levels of basic fibroblast growth factor (bFGF), interleukin 8 (CXCL8), and matrix metalloproteinase (MMP 9). In vitro analysis demonstrated that Bcl-2 expressing tumor cells secreted bFGF and vascular endothelial growth factor (VEGF) into culture supernatants. Microarray analysis of Bcl-2 expressing PC-3 cells demonstrated increased transcription of genes involved in metabolism, such as interleukins, growth factors, tumor necrosis factors (TNF) family members, and peptidases. CONCLUSIONS Together, these results demonstrate that Bcl-2 can regulate tumoral angiogenesis and lymphangiogenesis and suggest that therapy targeted at Bcl-2 expression, angiogenesis, and lymphangiogenesis may synergistically modulate tumor growth and confirm that Bcl-2 is a pivotal target for cancer therapy. Prostate 69:459,470, 2009. © 2008 Wiley-Liss, Inc. [source] Induction of apoptosis in the LNCaP human prostate carcinoma cell line and prostate adenocarcinomas of SV40T antigen transgenic rats by the Bowman,Birk inhibitorPATHOLOGY INTERNATIONAL, Issue 11 2009MingXi Tang The soybean-derived serine protease inhibitor, Bowman,Birk inhibitor (BBI), has been reported as a potent chemoprevention agent against several types of tumors. The present study was undertaken to evaluate the effects of BBI on androgen-sensitive/dependent prostate cancers using a human prostate cancer cell (LNCaP) and the transgenic rats developing adenocarcinoma of the prostate (TRAP) model. Treatment of LNCaP prostate cancer cells with 500 µg/mL BBI resulted in inhibition of viability measured on WST-1 assays, with induction of connexin 43 (C×43) and cleaved caspase-3 protein expression. Feeding of 3% roughly prepared BBI (BBIC) to TRAP from the age 3 weeks to 13 weeks resulted in significant reduction of the relative epithelial areas within the acinus and multiplicity of the adenocarcinomas in the lateral prostate lobes. C×43- and terminal deoxynucleotidyl transferase mediated dUTP-biotin end labeling of fragmented DNA (TUNEL)-positive apoptotic cancer cells were more frequently observed in the lateral prostates treated with BBIC than in the controls. These in vivo and in vitro results suggest that BBI possesses chemopreventive activity associated with induction of C×43 expression and apoptosis. [source] Prohibitin regulates TGF-, induced apoptosis as a downstream effector of smad-dependent and -independent signalingTHE PROSTATE, Issue 1 2010Brian Zhu Abstract BACKGROUND Prohibitin (PHB), a protein located on the inner mitochondrial membrane and nuclei, is an intracellular effector of transforming growth factor-, (TGF-,) signaling in prostate cancer cells. This study investigated the involvement of PHB in the apoptosis and survival outcomes of human prostate cancer cell to TGF-,. shRNA PHB loss of function in prostate cancer cells led to enhanced apoptotic response to TGF-, via Smad-dependent mechanism. METHOD TGF-, activation of Raf-Erk intracellular signaling, led to PHB phosphorylation, decreased inner mitochondrial permeability, and increased cell survival. Calcein-based immunofluorescence studies revealed the functional involvement of PHB in maintaining inner mitochondrial membrane permeability as an integral component of TGF-, induced apoptosis in prostate cancer cells. RESULTS These finding indicates that induction of TGF-, apoptosis is mediated by Smad-dependent and Smad-independent signaling (MAPK) converging at PHB as a downstream effector regulating inner mitochondrial permeability. Putative PHB associated proteins were identified by subjecting TGF-, treated cells to immunoprecipitation with anti-PHB, and mass spectrometry. A screen for the kinase specific phosphorylation sites of PHB revealed three protein kinase (PKC) binding sites. CONCLUSION Our results demonstrate that TGF-, led to upregulation of the PKC inhibitor 14-3-3 protein and promoted its association with PHB, while PHB association with PKC-,, was inhibited by the MEK1 inhibitor, documenting a critical interdependence between the MEK-ERK signaling and prohibitin phosphorylation. These findings suggest a dual role for PHB as a downstream determinant of the cellular response to TGF-, via Smad-dependent pathway (apoptosis) and MAPK intracellular signaling (survival). Prostate 70: 17,26, 2010. © 2009 Wiley-Liss, Inc. [source] Chromosome 18 suppresses tumorigenic properties of human prostate cancer cellsGENES, CHROMOSOMES AND CANCER, Issue 3 2006Audrey Gagnon Although prostate cancer is still the most diagnosed cancer in men, most genes implicated in its progression are yet to be identified. Chromosome abnormalities have been detected in human prostate tumors, many of them associated with prostate cancer progression. Indeed, alterations (including deletions or amplifications) of more than 15 human chromosomes have been reported in prostate cancer. We hypothesized that transferring normal human chromosomes into human prostate cancer cells would interfere with their tumorigenic and/or metastatic properties. We used microcell-mediated chromosome transfer to introduce human chromosomes 10, 12, 17, and 18 into highly tumorigenic (PC-3M-Pro4) and highly metastatic (PC-3M-LN4) PC-3-derived cell lines. We tested the in vitro and in vivo properties of these hybrids. Introducing chromosome 18 into the PC-3M-LN4 prostate cancer cell line greatly reduced its tumorigenic phenotype. We observed retarded growth in soft agar, decreased invasiveness through Matrigel, and delayed tumor growth into nude mice, both subcutaneously and orthotopically. This phenotype is associated with a marker in the 18q21 region. Combined with the loss of human chromosome 18 regions often seen in patients with advanced prostate cancer, our results show that chromosome 18 encodes one or more tumor-suppressor genes whose inactivation contributes to prostate cancer progression. © 2005 Wiley-Liss, Inc. [source] A Novel Secobetulinic Acid 3,4-Lactone from Viburnum aboricolumHELVETICA CHIMICA ACTA, Issue 3 2003Yuan-Ling Ku Bio-assay-guided fractionation of the CHCl3 -soluble extract from the leaves of Viburnum aboricolum led to the isolation of a novel secobetulinic acid 3,4-lactone, viburolide (=(6,)-4,6-dihydroxy-3,4-secolup-20(29)-ene-3,28-dioic acid 3,4-lactone; 1). This is the first lupane-type compound possessing such a lactone skeleton from natural products. Its structure was elucidated by spectral analysis and comparison with 6-dehydroxy-20,29-dihydroviburolide (6) prepared from benzyl betulinate (2). Compound 6 was found to inhibit androgen-independent human prostate cancer cells (PC-3) with an IC50 of 12.3,,M. [source] Regulation of HER expression and transactivation in human prostate cancer cells by a targeted cytotoxic bombesin analog (AN-215) and a bombesin antagonist (RC-3095)INTERNATIONAL JOURNAL OF CANCER, Issue 8 2010Sandra Sotomayor Abstract Bombesin (BN) and gastrin-releasing peptide (GRP) have been shown to stimulate the growth of human prostate cancer in vivo and in vitro by mechanisms initiated by binding of the peptide to BN/GRP receptor (GRPR). GRPR is overexpressed in a variety of human cancers, including human prostatic carcinoma. This led us to evaluate the effectiveness of blocking GRPR and of chemotherapy targeted to GRPR in androgen-dependent (LNCaP) and androgen-independent (PC-3) prostate cancer cells, which exhibit different features of disease progression. Thus, we used a cytotoxic BN/GRP analog, AN-215, consisting of 2-pyrrolinodoxorubicin (AN-201) linked to BN-like carrier peptide, and a BN/GRP receptor antagonist, RC-3095. Semiquantitative RT-PCR and Western blotting revealed that mRNA and protein levels for GRPR increased in prostate cancer cells as compared with nonneoplastic RWPE-1 cells. Immunofluorocytochemistry and Western blot assays revealed that AN-215 was the most effective analog decreasing both the expression of epidermal growth factor receptor family members and the activation of epidermal growth factor receptor and HER-2, which are associated to a poor prognosis. Furthermore, analogs targeted to BN/GRP receptors, AN-215 and RC-3095, blocked the effect of BN on cell growth in RWPE-1, LNCaP and PC-3 cells. These findings shed light on the mechanisms of action of these analogs and support the view that the use of AN-215 and RC-3095 for blocking BN/GRP receptors for targeted therapy may be of benefit for treatment of advanced prostate cancer. [source] Inhibition of prostaglandin synthesis and actions by genistein in human prostate cancer cells and by soy isoflavones in prostate cancer patientsINTERNATIONAL JOURNAL OF CANCER, Issue 9 2009Srilatha Swami Abstract Soy and its constituent isoflavone genistein inhibit the development and progression of prostate cancer (PCa). Our study in both cultured cells and PCa patients reveals a novel pathway for the actions of genistein, namely the inhibition of the synthesis and biological actions of prostaglandins (PGs), known stimulators of PCa growth. In the cell culture experiments, genistein decreased cyclooxygenase-2 (COX-2) mRNA and protein expression in both human PCa cell lines (LNCaP and PC-3) and primary prostate epithelial cells and increased 15-hydroxyprostaglandin dehydrogenase (15-PGDH) mRNA levels in primary prostate cells. As a result genistein significantly reduced the secretion of PGE2 by these cells. EP4 and FP PG receptor mRNA were also reduced by genistein, providing an additional mechanism for the suppression of PG biological effects. Further, the growth stimulatory effects of both exogenous PGs and endogenous PGs derived from precursor arachidonic acid were attenuated by genistein. We also performed a pilot randomised double blind clinical study in which placebo or soy isoflavone supplements were given to PCa patients in the neo-adjuvant setting for 2 weeks before prostatectomy. Gene expression changes were measured in the prostatectomy specimens. In PCa patients ingesting isoflavones, we observed significant decreases in prostate COX-2 mRNA and increases in p21 mRNA. There were significant correlations between COX-2 mRNA suppression, p21 mRNA stimulation and serum isoflavone levels. We propose that the inhibition of the PG pathway contributes to the beneficial effect of soy isoflavones in PCa chemoprevention and/or treatment. © 2008 Wiley-Liss, Inc. [source] Identifying the differential effects of silymarin constituents on cell growth and cell cycle regulatory molecules in human prostate cancer cellsINTERNATIONAL JOURNAL OF CANCER, Issue 1 2008Gagan Deep Abstract Prostate cancer (PCa) is the leading cause of cancer-related deaths in men; urgent measures are warranted to lower this deadly malignancy. Silymarin is a known cancer chemopreventive agent, but the relative anticancer efficacy of its constituents is still unknown. Here, we compared the efficacy of 7 pure flavonolignan compounds isolated from silymarin, namely silybin A, silybin B, isosilybin A, isosilybin B, silydianin, isosilydianin, silychristin and isosilychristin, in advanced human PCa PC3 cells. Silybin A, silybin B, isosilybin A, isosilybin B, silibinin and silymarin strongly inhibited the colony formation by PC3 cells (p < 0.001), while silydianin, silychristin and isosilychristin had marginal effect (p < 0.05). Using cell growth and death assays, we identified isosilybin B as the most effective isomer. FACS analysis for cell cycle also showed that silybin A, silybin B, isosilybin A, isosilybin B, silibinin and silymarin treatment resulted in strong cell cycle arrest in PC3 cells after 72 hr of treatment, while the effect of silydianin, silychristin and isosilychristin was marginal (if any). Western blot analysis also showed the differential effect of these compounds on the levels of cell cycle regulators-cyclins (D, E, A and B), CDKs (Cdk2, 4 and Cdc2), CDKIs (p21 and p27) and other cell cycle regulators (Skp2, Cdc25A, B, C and Chk2). This study provided further evidence for differential anticancer potential among each silymarin constituent, which would have potential implications in devising better formulations of silymarin against prostate and other cancers. © 2008 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] 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] Biochanin A induction of sulfotransferases in ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 2 2010Yue Chen Abstract Biochanin A (BCA) is a dietary isoflavone present in red clover (Trifoliumn pretense) and many herbal products. BCA has been reported to have chemopreventive actions against various cancers including prostate, breast, colon cancer, and so on. Sulfotransferases are a family of phase II drug-metabolizing enzymes, which are important for xenobiotic detoxification and regulation of biological signaling molecule biological activities. Sulfotransferase gene expressions are regulated by different hormones and xenobiotics. Improper regulation of sulfotransferases leads to improper functions of biological signaling molecules, which in turn can cause cancer or other diseases. BCA inhibits the enzyme activities of the phase I drug-metabolizing enzymes CYP1A1 and CYP1B1 in Chinese hamster ovary cells and induces the phase II drug-metabolizing enzymes UDP-glucuronosyltransferases in human prostate cancer cells. BCA induction of sulfotransferases has not been studied. This investigation evaluates the in vivo regulation of sulfotransferases at protein and mRNA levels in the liver and intestine of Sprague-Dawley rats treated with BCA (0, 2, 10, and 50 mg/kg/day) for 7 days. Our experimental results demonstrate for the first time that chronic BCA treatment can significantly induce the expression of rat sulfotransferase 1A1 (rSULT1A1, AST-IV), sulfotransferase 2A1 (rSULT2A1, STa), and rat estrogen sulfotransferase (rSULT1E1, EST) in rat liver and intestine. Our Western blot results are in good agreement with real-time RT-PCR data, suggesting that BCA induction of sulfotransferases occurs at the transcriptional level. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:102,114, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20318 [source] Vesicle traffic through intercellular bridges in DU 145 human prostate cancer cellsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2004Cristina Vidulescu Abstract We detected cell-to-cell communication via intercellular bridges in DU 145 human prostate cancer cells by fluorescence microscopy. Since DU 145 cells have deficient gap junctions, intercellular bridges may have a prominent role in the transfer of chemical signals between these cells. In culture, DU 145 cells are contiguous over several cell diameters through filopodial extensions, and directly communicate with adjacent cells across intercellular bridges. These structures range from 100 nm to 5 ,m in diameter, and from a few microns to at least 50,100 ,m in length. Time-lapse imagery revealed that (1) filopodia rapidly move at a rate of microns per minute to contact neighboring cells and (2) intercellular bridges are conduits for transport of membrane vesicles (1,3 ,m in diameter) between adjacent cells. Immunofluorescence detected alpha-tubulin in intercellular bridges and filopodia, indicative of microtubule bundles, greater than a micron in diameter. The functional meaning, interrelationship of these membrane extensions are discussed, along with the significance of these findings for other culture systems such as stem cells. Potential applications of this work include the development of anticancer therapies that target intercellular communication and controlling formation of cancer spheroids for drug testing. [source] Microtubule-associated protein tau in human prostate cancer cells: Isoforms, phosphorylation, and interactions,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2009Skye Souter Abstract Tau is a microtubule-associated protein whose function has been investigated primarily in neurons. Recently, tau expression has been correlated with increased drug resistance in various cancers of non-neuronal tissues. In this report, we investigate the tau expressed in cancerous prostate lines ALVA-31, DU 145, and PC-3. Prostate cancer tau is heat-stable and highly phosphorylated, containing many of the modifications identified in Alzheimer's disease brain tau. RT-PCR and phosphatase treatment indicated that all six alternatively spliced adult brain tau isoforms are expressed in ALVA-31 cells, and isoforms containing exon 6 as well as high molecular weight tau isoforms containing either exon 4A or a larger splice variant of exon 4A are also present. Consistent with its hyperphosphorylated state, a large proportion of ALVA-31 tau does not bind to microtubules, as detected by confocal microscopy and biochemical tests. Finally, endogenous ALVA-31 tau can interact with the p85 subunit of phosphatidylinositol 3-kinase, as demonstrated by co-immunoprecipitations and in vitro protein-binding assays. Our results suggest that tau in prostate cancer cells does not resemble that from normal adult brain and support the hypothesis that tau is a multifunctional protein. J. Cell. Biochem. 108: 555,564, 2009. © 2009 Wiley-Liss, Inc. [source] Diffusion-weighted MRI for monitoring tumor response to photodynamic therapyJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2010Hesheng Wang MS Abstract Purpose: To examine diffusion-weighted MRI (DW-MRI) for assessing the early tumor response to photodynamic therapy (PDT). Materials and Methods: Subcutaneous tumor xenografts of human prostate cancer cells (CWR22) were initiated in athymic nude mice. A second-generation photosensitizer, Pc 4, was delivered to each animal by a tail vein injection 48 h before laser illumination. A dedicated high-field (9.4 Tesla) small animal MR scanner was used to acquire diffusion-weighted MR images pre-PDT and 24 h after the treatment. DW-MRI and apparent diffusion coefficients (ADC) were analyzed for 24 treated and 5 control mice with photosensitizer only or laser light only. Tumor size, prostate specific antigen (PSA) level, and tumor histology were obtained at different time points to examine the treatment effect. Results: Treated mice showed significant tumor size shrinkage and decrease of PSA level within 7 days after the treatment. The average ADC of the 24 treated tumors increased 24 h after PDT (P < 0.001) comparing with pre-PDT. The average ADC was 0.511 ± 0.119 × 10,3 mm2/s pre-PDT and 0.754 ± 0.181 × 10,3 mm2/s 24 h after the PDT. There is no significant difference in ADC values pre-PDT and 24 h after PDT in the control tumors (P = 0.20). Conclusion: The change of tumor ADC values measured by DW-MRI may provide a noninvasive imaging marker for monitoring tumor response to Pc 4-PDT as early as 24 h. J. Magn. Reson. Imaging 2010;32:409,417. © 2010 Wiley-Liss, Inc. [source] The effects of RANK blockade and osteoclast depletion in a model of pure osteoblastic prostate cancer metastasis in boneJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2005Peter G. Whang Abstract Adenocarcinoma of the prostate exhibits a clear propensity for bone and is associated with the formation of osteoblastic metastases. It has previously been suggested that osteoclast activity may be necessary for the development of these osteoblastic metastases based on data from lytic and mixed lytic-blastic tumors. Here we investigate the effects of complete in vivo osteoclast depletion via the blockade of receptor activator of NF:,B (RANK) on the establishment and progression of purely osteoblastic (LAPC-9 cells) bone lesions induced by human prostate cancer cells using a SCID mouse intratibial injection model. The subcutaneous administration of the RANK antagonist (15 mg/kg) RANK:Fc did not prevent the formation of purely osteoblastic lesions, indicating that osteoclasts may not be essential to the initial development of osteoblastic metastases. However, RANK:Fc protein appeared to inhibit the progression of established osteoblastic lesions, suggesting that osteoclasts may be involved in the subsequent growth of these tumors once they are already present. In contrast, RANK:Fc treatment effectively blocked the establishment and progression of purely osteolytic lesions formed by PC-3 cells, which served as a positive control. These results indicate that in vivo RANK blockade may not be effective for the prevention of osteoblastic metastasis but may potentially represent a novel therapy that limits the growth of established metastatic CaP lesions in bone. © 2005 Published by Elsevier Ltd. on behalf of Orthopaedic Research Society. [source] Signaling mechanisms of melatonin in antiproliferation of hormone-refractory 22Rv1 human prostate cancer cells: implications for prostate cancer chemopreventionJOURNAL OF PINEAL RESEARCH, Issue 2 2007Chun W. Tam Abstract:, There is an unmet clinical demand for safe and effective pharmaceuticals/nutraceuticals for prostate cancer prevention and hormone-refractory prostate cancer treatment. Previous laboratory and human studies of our laboratory demonstrated an association between the antiproliferative action of melatonin and melatonin MT1 receptor expression in prostate cancer. The aim of this study was to determine, using a pharmacological approach, the signaling mechanisms of melatonin in hormone-refractory 22Rv1 human prostate cancer cell antiproliferation. Both immunoreactive MT1 and MT2 subtypes of G protein-coupled melatonin receptor were expressed in 22Rv1 cells. Melatonin inhibited, concentration dependently, cell proliferation, upregulated p27Kip1 gene transcription and protein expression, and downregulated activated androgen signaling in 22Rv1 cells. While the effects of melatonin were mimicked by 2-iodomelatonin, a high-affinity nonselective MT1 and MT2 receptor agonist, melatonin effects were blocked by luzindole, a nonselective MT1 and MT2 receptor antagonist, but were unaffected by 4-phenyl-2-propionamidotetraline, a selective MT2 receptor antagonist. Importantly, we discovered that the antiproliferative effect of melatonin exerted via MT1 receptor on p27Kip1 gene and protein upregulation is mediated by a novel signaling mechanism involving co-activation of protein kinase C (PKC) and PKA in parallel. Moreover, we also showed that a melatonin/MT1/PKC mechanism is involved in melatonin-induced downregulation of activated androgen signal transduction in 22Rv1 cells. Taken together with the known molecular mechanisms of prostate cancer progression and transition to androgen independence, our data provide strong support for melatonin to be a promising small-molecule useful for prostate cancer primary prevention and secondary prevention of the development and progression of hormone refractoriness. [source] Regulation of signaling pathways involved in lupeol induced inhibition of proliferation and induction of apoptosis in human prostate cancer cellsMOLECULAR CARCINOGENESIS, Issue 12 2008Sahdeo Prasad Abstract Prostate cancer (PCa) is the most frequently diagnosed noncutaneous cancer and the leading cause of cancer related deaths in men in the United States and many other Asian countries. Dietary factors are considered as a strategic agent to control the risk of PCa. Lupeol, a triterpene, present in fruits and medicinal plants, has been shown to possess many pharmacological properties including anticancer effects. Here, effect of lupeol on cell proliferation and cell death was evaluated using human PCa cells, PC-3. In MTT assay, lupeol inhibited the cell proliferation (12,71%) in dose (50,800 µM) and time dependent manner. Flow-cytometric analysis of cell-cycle revealed that an antiproliferative effect of lupeol (400,600 µM) is associated with an increase in G2/M-phase arrest (34,58%). RT-PCR analysis showed that lupeol-induced G2/M-phase arrest was mediated through the inhibition of cyclin regulated signaling pathway. Lupeol inhibited the expression of cyclin B, cdc25C, and plk1 but induced the expression of 14-3-3, genes. However no changes were observed in the expression of gadd45, p21waf1/cip1 and cdc2 genes. Results of western blot showed that lupeol regulates the phosphorylation of cdc2 (Tyr15) and cdc25C (Ser198). Further, on increase of lupeol exposure to PC-3 cells an induction of apoptosis was recorded, which was associated with upregulation of bax, caspase-3, -9, and apaf1 genes and down regulation of antiapoptotic bcl-2 gene. The role of caspase-induced apoptosis was confirmed by increase in reactive oxygen species, loss of mitochondrial membrane potential followed by DNA fragmentation. Thus, our study suggests that lupeol possess novel antiproliferative and apoptotic potential against PCa. © 2008 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] Prostate-specific antitumor activity by probasin promoter-directed p202 expression,MOLECULAR CARCINOGENESIS, Issue 3 2003Yong Wen Abstract p202, an interferon (IFN) inducible protein, arrests cell cycle at G1 phase leading to cell growth retardation. We previously showed that ectopic expression of p202 in human prostate cancer cells renders growth inhibition and suppression of transformation phenotype in vitro. In this report, we showed that prostate cancer cells with stable expression of p202 were less tumorigenic than the parental cells. The antitumor activity of p202 was further demonstrated by an ex vivo treatment of prostate cancer cells with p202 expression vector that showed significant tumor suppression in mouse xenograft model. Importantly, to achieve a prostate-specific antitumor effect by p202, we employed a prostate-specific probasin (ARR2PB) gene promoter to direct p202 expression (ARR2PB-p202) in an androgen receptor (AR),positive manner. The ARR2PB-p202/liposome complex was systemically administered into mice bearing orthotopic AR-positive prostate tumors. We showed that parenteral administration of an ARR2PB-p202/liposome preparation led to prostate-specific p202 expression and tumor suppression in orthotopic prostate cancer xenograft model. Furthermore, with DNA array technique, we showed that the expression of p202 was accompanied by downregulation of G2/M phase cell-cycle regulators, cyclin B, and p55cdc. Together, our results suggest that p202 suppresses prostate tumor growth, and that a prostate-specific antitumor effect can be achieved by systemic administration of liposome-mediated delivery of ARR2PB-p202. © 2003 Wiley-Liss, Inc. [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] Signal transduction responses to lysophosphatidic acid and sphingosine 1-phosphate in human prostate cancer cellsTHE PROSTATE, Issue 14 2009Terra C. Gibbs Abstract BACKGROUND Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are lipid mediators that bind to G-protein-coupled receptors. In this study, signaling responses to 18:1 LPA and S1P were examined in parallel in three human prostate cancer cell lines: PC-3, Du145, and LNCaP. METHODS Receptor expression was assessed by RT-PCR, Northern blotting, and immunoblotting. Cellular responses to mediators were studied by proliferation assays, phosphoprotein immunoblotting, and phospholipid metabolism assays. RESULTS All cell lines express mRNA for both LPA and S1P receptors. PC-3 and Du145, but not LNCaP, proliferate in response to LPA and S1P. Epidermal growth factor (EGF), phorbol 12-myristate 13-acetate (PMA), LPA, and S1P induce activation of Erks in PC-3 and Du145; only EGF and PMA activate Erks in LNCaP. In Du145 and PC-3, Akt is activated by EGF, LPA, and S1P. Akt is constitutively active in LNCaP; EGF but not LPA or S1P stimulates further phosphorylation. FAK is phosphorylated in response to both LPA and S1P in PC-3 and Du145, but not in LNCaP. LPA and S1P stimulate phospholipase D (PLD) activity to varying extents in the different cell lines. Notably, both lipid mediators activate PLD in LNCaP. In Du145, LPA, but not S1P, activates PLD and enhances cellular production of LPA. CONCLUSIONS Although both LPA and S1P induce signal transduction in all prostate cancer cell lines studied, a proliferation response is observed only when the Erk, Akt, and FAK pathways are activated. Other responses to the lipid mediators, such as PLD activation, likely contribute to other cellular outcomes. Prostate 69: 1493,1506, 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] Bcl-2 mediated modulation of vascularization in prostate cancer xenografts,THE PROSTATE, Issue 5 2009Yoshihisa Sakai Abstract PURPOSE We previously demonstrated that Bcl-2 overexpression enhances the radiation resistance of PC-3 human prostate cancer cells and xenografts by inhibiting apoptosis, increasing proliferation, and promoting angiogenesis. To further elucidate the relationship between Bcl-2 expression and the angiogenic potential of PC-3-Bcl-2 cells, tumorigenicity, angiogenesis, and lymphangiogenesis were evaluated and compared in a Bcl-2 overexpressing clone in vitro and in vivo. EXPERIMENTAL DESIGN Human prostate cancer cells over expressing Bcl-2 were studied in vitro and in vivo to determine the angiogenic and lymphangiogenic properties of these cells. RESULTS Increased Bcl-2 expression enhanced the tumorigenicity of prostate cancer xenografts. It also enhanced the expression and secretion of key angiogenic and lymphangiogenic factors that stimulated the synthesis of CD31-positive blood vessels and LYVE-1 positive lymphatics. Specifically, the increased angiogenic and lymphangiogenic potential correlated with increased serum levels of basic fibroblast growth factor (bFGF), interleukin 8 (CXCL8), and matrix metalloproteinase (MMP 9). In vitro analysis demonstrated that Bcl-2 expressing tumor cells secreted bFGF and vascular endothelial growth factor (VEGF) into culture supernatants. Microarray analysis of Bcl-2 expressing PC-3 cells demonstrated increased transcription of genes involved in metabolism, such as interleukins, growth factors, tumor necrosis factors (TNF) family members, and peptidases. CONCLUSIONS Together, these results demonstrate that Bcl-2 can regulate tumoral angiogenesis and lymphangiogenesis and suggest that therapy targeted at Bcl-2 expression, angiogenesis, and lymphangiogenesis may synergistically modulate tumor growth and confirm that Bcl-2 is a pivotal target for cancer therapy. Prostate 69:459,470, 2009. © 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] Antisense MDM2 enhances the response of androgen insensitive human prostate cancer cells to androgen deprivation in vitro and in vivoTHE PROSTATE, Issue 6 2008Zhaomei Mu Abstract Background Antisense MDM2 oligonucleotide (AS-MDM2) sensitizes androgen sensitive LNCaP cells to androgen deprivation (AD) in vitro and in vivo. In this study, we investigated the effects of AS-MDM2 combined with AD on androgen resistant LNCaP (LNCaP-Res) and moderately androgen resistant bcl-2 overexpressing LNCaP (LNCaP-BST) cells. Methods The LNCaP-Res cell line was generated by culturing LNCaP cells in medium containing charcoal-stripped serum for more than 1 year. Apoptosis was quantified in vitro by Annexin V staining and caspase 3,+,7 activity. For the in vivo studies, orthotopic tumor growth was monitored by magnetic resonance imaging (MRI). AS-MDM2 and the mismatch control were given by i.p. injection at doses of 25 mg/kg per day, 5 days/week for 15 days. Results LNCaP-Res cells expressed high levels of androgen receptor (AR) and bcl-2, and displayed no growth inhibition to AD. AS-MDM2 caused significant reductions in MDM2 and AR expression, and increases in p53 and p21 expression in both cell lines. AS-MDM2,+,AD resulted in the highest levels of apoptosis in vitro and tumor growth inhibition in vivo in both cell lines; although, these effects were less pronounced in LNCaP-BST cells. Conclusions AS-MDM2,+,AD enhanced apoptotic cell death in vitro and tumor growth inhibition in vivo in androgen resistant cell lines. The action of AS-MDM2,+,AD was influenced somewhat by bcl-2 expression as an isolated change (LNCaP-BST cells), but not when accompanied by other molecular changes associated with androgen insensitivity (LNCaP-Res cells). MDM2 knockdown has promise for the treatment of men with early hormone refractory disease. Prostate 68: 599,609, 2008. © 2008 Wiley-Liss, Inc. [source] Prostate-Specific genes and their regulation by dihydrotestosteroneTHE PROSTATE, Issue 3 2008Ma Ci Abstract BACKGROUND Prostate is a well-known androgen-dependent tissue. METHODS By sequencing 4,294,186 serial analysis of gene expression (SAGE) tags, we have investigated the transcriptomes of normal mouse prostate, liver, testis, lung, brain, femur, skin, adipose tissue, skeletal muscle, vagina, ovary, mammary gland, and uterus in order to identify the most abundant and tissue-specific transcripts in the prostate, as well as to target the androgen responsive transcripts specifically regulated in the prostate. Small interference RNA (siRNA) in LNCaP cells was applied to validate the roles of prostate-specific/enriched ARGs in the growth of human prostate cancer cells. RESULTS The most abundant transcripts were involved in prostatic secretion, energy metabolism and immunity. Previously well-known prostate-specific transcripts, including many transcripts involved in prostatic secretion, polyamine biosynthesis and transport, and immunity were specific/enriched in the prostate. Only 22 transcripts among 114 androgen-regulated genes (ARGs) in the mouse prostate were modulated by dihydrotestosterone (DHT) in two or more tissues. The siRNA results showed that inhibition of HSPA5 and MAT2A gene expression repressed growth of human cancer LNCaP cells. Conclusions The current study globally assessed the transcriptome of the prostate and revealed the most abundant and tissue-specific transcripts which are responsible for the unique functions of this organ. These prostate-specific ARGs might be used as targets to develop safe and effective gene-based therapy for the prevention and treatment of prostate cancer. Prostate 68: 241,254, 2008. © 2007 Wiley-Liss, Inc. [source] The polycomb group protein EZH2 regulates actin polymerization in human prostate cancer cellsTHE PROSTATE, Issue 3 2008R.J. Bryant Abstract BACKGROUND The Polycomb Group protein EZH2 is implicated in prostate cancer progression. EZH2 promotes prostate cancer cell proliferation and invasiveness. We describe a link between EZH2 function and actin polymerization in prostate cancer cells. METHODS Nuclear and cytoplasmic EZH2 expression in benign and malignant prostate tissue samples was assessed. An association between EZH2 function and actin polymerization in prostate cancer cells was investigated using siRNA-mediated knock-down of EZH2. Effects of EZH2 knock-down on actin polymerization dynamics were analyzed biochemically using immunoblot analysis of cell lysate fractions, and morphologically using immunocytochemistry. RESULTS Cytoplasmic EZH2 is expressed at low levels in benign prostate epithelial cells and over-expressed in prostate cancer cells. Cytoplasmic EZH2 expression levels correlate with nuclear EZH2 expression in prostate cancer samples. Knock-down of EZH2 in PC3 prostate cancer cells increases the amount of F-actin polymerization, cell size, and formation of actin-rich filaments. CONCLUSIONS Cytoplasmic EZH2 is over-expressed in prostate cancer cells. EZH2 function promotes a reduction in the pool of insoluble F-actin in invasive prostate cancer cells. EZH2 may regulate actin polymerization dynamics and thereby promote prostate cancer cell motility and invasiveness. Prostate 68: 255,263, 2008. © 2007 Wiley-Liss, Inc. [source] S179D prolactin sensitizes human prostate cancer cells such that physiological concentrations of 1, 25 dihydroxy vitamin D3 result in growth inhibition and cell deathTHE PROSTATE, Issue 14 2007Wei Wu Abstract BACKGROUND S179D Prolactin (PRL) is a molecular mimic of naturally phosphorylated human PRL which has been shown to inhibit the growth of human prostate cancer cells both in vitro and when grown as tumors in nude mice. METHODS In the current study, we have investigated the potential interplay between S179D PRL and 1,25 dihydroxy vitamin D3 (1,25D) in the inhibition of prostate cancer cell growth by incubating cells under circumstances where each hormone alone has no effect. RESULTS Incubation of DU145 or PC3 cells in 100 pM 1,25D or 10 nM S179D PRL for 3 days showed no effect of each alone on expression of the vitamin D receptor (VDR), or the cell cycle regulatory protein p21, or on cell number. Incubation in both together increased expression of the VDR and p21 two to threefold. This co-operative effect was reproduced when activation of the p21 promoter was analyzed using a p21-luciferase (p21-luc) construct. Elimination of the VDR response element from p21-luc eliminated response to the hormone combination, showing that the effect on p21 was through the VDR. Most importantly, S179D PRL sensitized the cells to 1,25D such that there was a concentration-related reduction in cell number versus controls between 40 and 160 pM. At least part of this effect was via the induction of cell death. CONCLUSIONS These results suggest that combined anti-tumor therapy may be very efficacious and that the dose of 1,25D required may be below the range that results in hypercalcemia. Prostate 67: 1498,1506, 2007. © 2007 Wiley-Liss, Inc. [source] Androgen receptor or estrogen receptor-, blockade alters DHEA-, DHT-, and E2 -induced proliferation and PSA production in human prostate cancer cellsTHE PROSTATE, Issue 11 2007Julia T. Arnold Abstract BACKGROUND Dehydroepiandrosterone (DHEA) is an endogenous steroid that is metabolized to androgens and/or estrogens in the human prostate. DHEA levels decline with age, and use of DHEA supplements to retard the aging process is of unproved effectiveness and safety. LNCaP and LAPC-4 prostate cancer cells were used to determine whether DHEA-modulated proliferation and prostate specific antigen (PSA) production were mediated via the androgen receptor (AR) and/or ER,. METHODS Cells were treated with DHEA, DHT, or E2 and antagonists to AR (Casodex®-bicalutamide) or ER (ICI 182,780) or siRNA to the respective receptors. Proliferation was assessed by MTT assay and PSA mRNA and protein secretion were measured by quantitative real-time PCR and ELISA. Associations of AR and ER, were analyzed by co-immunoprecipitation studies and fluorescent confocal microscopy. RESULTS DHEA-, T-, and E2 -induced proliferation of LNCaP cells was blunted by Casodex but not by ICI treatment. In LNCaP cells, Casodex and ICI suppressed hormone-induced PSA production. In LAPC-4 cells, DHT-stimulated PSA mRNA was inhibited by Casodex and ICI, and the minimal stimulation by DHEA was inhibited by ICI. Use of siRNAs confirmed involvement of AR and ER, in hormone-induced PSA production while AR-ER, co-association was suggested by immunoprecipitation and nuclear co-localization. CONCLUSIONS These findings support involvement of both AR and ER, in mediating DHEA-, DHT-, and E2 -induced PSA expression in prostate cancer cells. Prostate 67: 1152,1162, 2007. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||