Project description:Deregulation of cytokine- and growth factor signaling due to altered expression of endogenous regulators is well recognized in prostate and other cancers. Suppressor of cytokine signaling 2 (SOCS2) is a key regulator of growth hormone, IGF and prolactin signaling, that have been implicated in carcinogenesis. In this study we elucidate expression pattern and functional significance of SOCS2 in prostate cancer (PCa). Protein expression analysis employing tissue microarrays from two independent patient cohorts revealed significantly enhanced expression in tumor compared to benign tissue as well as association with Gleason score and disease progression. In vitro and in vivo assays uncovered the involvement of SOCS2 in the regulation of cell growth and apoptosis. Functionally, SOCS2 knockdown inhibited prostate cancer cell proliferation and xenograft growth in a CAM assay. Decreased cell growth after SOCS2 downregulation was associated with cell-cycle arrest and apoptosis. In addition, we prove for the first time that SOCS2 expression is significantly elevated upon androgenic stimulation in androgen receptor-positive cell lines, providing a possible mechanistic explanation for high SOCS2 levels in PCa tissue. Consequently, SOCS2 expression correlated with androgen receptor expression in malignant tissue of patients. Taken together, our study linked increased SOCS2 expression in PCa with a pro-proliferative role in vitro and in vivo. Prostate cancer cell lines LNCaP, DUCaP and VCaP cells were cultured in the absence or presence of R1881, an androgen in three independent experiments. Differential gene expression was determined by comparing R1881 treated samples with the corresponding controls (EtOH treated samples).
Project description:Deregulation of cytokine- and growth factor signaling due to altered expression of endogenous regulators is well recognized in prostate and other cancers. Suppressor of cytokine signaling 2 (SOCS2) is a key regulator of growth hormone, IGF and prolactin signaling, that have been implicated in carcinogenesis. In this study we elucidate expression pattern and functional significance of SOCS2 in prostate cancer (PCa). Protein expression analysis employing tissue microarrays from two independent patient cohorts revealed significantly enhanced expression in tumor compared to benign tissue as well as association with Gleason score and disease progression. In vitro and in vivo assays uncovered the involvement of SOCS2 in the regulation of cell growth and apoptosis. Functionally, SOCS2 knockdown inhibited prostate cancer cell proliferation and xenograft growth in a CAM assay. Decreased cell growth after SOCS2 downregulation was associated with cell-cycle arrest and apoptosis. In addition, we prove for the first time that SOCS2 expression is significantly elevated upon androgenic stimulation in androgen receptor-positive cell lines, providing a possible mechanistic explanation for high SOCS2 levels in PCa tissue. Consequently, SOCS2 expression correlated with androgen receptor expression in malignant tissue of patients. Taken together, our study linked increased SOCS2 expression in PCa with a pro-proliferative role in vitro and in vivo.
Project description:This is a mathematical describing the interaction between the prostate adenocarcinoma tumor environment, the prostate specific antigen (PSA) produced by hormone-dependent and hormone-independent tumor cells, respectively, and the level of androgens.
Project description:Prostate epithelial cells depend on androgens for survival and function. In early prostate cancer, besides survival, androgens also regulated tumor growth, which is exploited by androgen ablation/ blockade therapies in metastatic disease. The aim of the present study was to characterize the role of the androgen receptor pathway in prostate cancer progression and to identify potential disease markers. Microarray analysis was used to establish the androgen-regulated gene expression profile, upon stimulation with the synthetic androgen R1881 or the antiandrogen hydroxyflutamide, of the androgen-responsive PC346C cell line and its derivative castration-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A mutated AR)
Project description:Aberrant androgen receptor (AR)-mediated transcription is a critical driver in progression of human prostate cancer. It's known that different doses of androgens can elicit differential transcriptional and proliferative responses in prostate-tumor cells. Here, we set out to examine the androgenic regulation of glycoprotein expression in the membrane fraction of prostate-tumor cells that could serve as mediators or markers of androgen-induced proliferative responses observed in prostate-tumor cells. A bioanalytical workflow involving lectin-affinity chromatography and label-free quantitative mass spectrometry was used to identify androgen-sensitive glycomembrane protein expression associated with androgen-mediated proliferation. This study would facilitate the identification of surface membrane proteins involved in androgen-mediated proliferation and provide potential therapeutic targets in the detection treatment of proliferation prostate-tumors.
Project description:Prostate epithelial cells depend on androgens for survival and function. In early prostate cancer, besides survival, androgens also regulated tumor growth, which is exploited by androgen ablation/ blockade therapies in metastatic disease. The aim of the present study was to characterize the role of the androgen receptor pathway in prostate cancer progression and to identify potential disease markers. Microarray analysis was used to establish the androgen-regulated gene expression profile, upon stimulation with the synthetic androgen R1881 or the antiandrogen hydroxyflutamide, of the androgen-responsive PC346C cell line and its derivative castration-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A mutated AR) PC346C, PC346DCC, PC346Flu1 and PC346Flu2 were stimulated with 1 nM R1881, 1uM hydroxyflutamide or vehicle control, following a 4, 8 and 16h time-course. Each condition was performed in dye-swap, using biological duplicates. PC346DCC was only stimulated with R1881, not hydroxyflutamide.
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis. FOXA1 ChIP-exo
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified a novel androgen-regulated long non-coding (lnc) RNA, SOCS2-AS1. In order to investigate the SOCS2-AS1 function in prostate cancer cells, we performed gene expression in AR-positive prostate cancer cell lines (LNCaP and LTAD) after siSOCS2-AS1 or siSOCS2 treatment. We also treated cells with vehicle or androgen to analyzed the effects of siSOCS2-AS1 on AR function. Observation of androgen dependent gene expression changes after treatmet with siSOCS2-AS1 with microarray.
Project description:The androgen receptor (AR) enacts metabolic effects of the anabolic steroid testosterone, but how AR-directed metabolic changes affect prostate cancer progression is not well understood. Here, we show that the AR increases de novo polyamine synthesis by direct transcriptional regulation of ornithine decarboxylase (ODC) expression across cell types, including prostate cancer cells. Likewise, androgen treatment of prostate cancer models increased intracellular and secreted polyamines, a process that was critical for tumor development as both genetic and pharmacologic inhibition of AR-induced polyamine synthesis enhanced growth inhibition of prostate cancer by supraphysiological androgens. This polyamine reduction lessened negative feedback regulation of S-adenosylmethionine synthase 1 (AMD1), enhancing its utilization of S-adenosylmethionine (SAM), which reduced global protein methylation patterns and expression of the protooncogene MYC. The ODC inhibitor difluoromethylornithine (DFMO) was effective in reduction of polyamines in patients with metastatic CRPC even despite treatment with bipolar androgen therapy, supporting further study of this therapy combination. Thus, the AR is a critical regulator of polyamine synthesis, which may constitute a vulnerability in prostate cancer treated with bipolar androgen therapy.
Project description:Protein 4.1B is a 4.1/ezrin/radixin/moesin (FERM) domain-containing protein whose expression is frequently lost in a variety of human tumors, including meningiomas, non-small-cell lung cancers and breast carcinomas. However, its potential tumor suppressive function under in vivo conditions remains to be validated. In a screen for genes involved with prostate cancer metastasis, we found that 4.1B expression is reduced in highly metastatic tumors. Downregulation of 4.1B increased the metastatic propensity of poorly metastatic cells in an orthotopic model of prostate cancer. Furthermore, 4.1B-deficient mice displayed increased susceptibility for developing aggressive, spontaneous prostate carcinomas. In both cases, enhanced tumor malignancy was associated with reduced apoptosis. As expression of Protein 4.1B is frequently downregulated in human clinical prostate cancer, as well as in a spectrum of other tumor types, these results suggest a more general role for Protein 4.1B as a negative regulator of cancer progression to metastatic disease. Experiment Overall Design: primary cell line vs metastasis cell line