Project description:To decipher the contribution of STAT3, IRF1 and PGAM5 to androgen-responsive gene expression, effect of siRNA-mediated silencing of STAT3, IRF1 and PGAM5 on expression of androgen-dependent genes was studied.
Project description:Galiellalactone (GL) is a fungal metabolite that presents antitumor and anti-inflammatory activities in vitro and in vivo. Previous studies have shown that GL targets NF-KB and STAT3 pathways and induces G2/M cell cycle arrest in androgen-insensitive prostate cancer cells. In this study, we show that GL-induced cell cycle arrest is independent of the NF-KB and STAT3 pathways in DU145 and PC-3 cells, and also that GL did not affect cell cycling in androgen-sensitive prostate cancer cell such as LNCaP and 22Rv1 cells. In addition, we showed confluence resistance to GL in DU145 cells. Using a SWATH proteomic approach we identified the down-regulation of Nucleolar and spindle associated protein 1 (NUSAP1) under DU145 confluence and in LNCaP cells. Also, the inhibition of NUSAP1 by siRNAs induced resistance to GL in DU145 cells, suggesting that NUSAP1 may be a target for GL and could be useful as biomarker for responsiveness of the antitumor activity of GL.
Project description:Prostate cancer is the second most occurring cancer in men worldwide, and with the advances made with screening for prostate-specific antigen, it has been prone to early diagnosis and over-treatment. To better understand the mechanisms of tumorigenesis and possible treatment responses, we developed a mathematical model of prostate cancer which considers the major signalling pathways known to be deregulated. The model includes pathways such as androgen receptor, MAPK, Wnt, NFkB, PI3K/AKT, MAPK, mTOR, SHH, the cell cycle, the epithelial-mesenchymal transition (EMT), apoptosis and DNA damage pathways. The final model accounts for 133 nodes and 449 edges. We applied a methodology to personalise this Boolean model to molecular data to reflect the heterogeneity and specific response to perturbations of cancer patients, using TCGA and GDSC datasets.
Project description:Following androgen ablation therapy (AAT), the vast majority of prostate cancer patients develop treatment resistance with a median time of 18-24 months to disease progression. To identify molecular targets that aid in prostate cancer cell survival and contribute to the androgen independent phenotype, we evaluated changes in LNCaP cell gene expression during 12 months of androgen deprivation. At time points reflecting critical growth and phenotypic changes, we performed Affymetrix expression array analysis to examine the effects of androgen deprivation during the acute response, during the period of apparent quiescence, and during the emergence of highly proliferative, androgen-independent prostate cancer cells (LNCaP-AI). We discovered alterations in gene expression for a host of molecules associated with promoting prostate cancer cell growth and survival, regulating cell cycle progression, apoptosis and adrenal androgen metabolism, in addition to AR co-regulators and markers of neuroendocrine disease. These findings illustrate the complexity and unpredictable nature of cancer cell biology and contribute greatly to our understanding of how prostate cancer cells likely survive AAT. The value of this longitudinal approach lies in the ability to examine gene expression changes throughout the cellular response to androgen deprivation; it provides a more dynamic illustration of those genes which contribute to disease progression in addition to specific genes which constitute a malignant androgen-independent phenotype. In conclusion, it is of great importance that we employ new approaches, such as the one proposed here, to continue exploring the cellular mechanisms of therapy resistance and identify promising targets to improve cancer therapeutics. Experiment Overall Design: To identify molecular targets that aid in prostate cancer cell survival and contribute to the androgen independent phenotype, we evaluated changes in LNCaP cell gene expression during 12 months of androgen deprivation. At time points reflecting critical growth and phenotypic changes, we performed Affymetrix expression array analysis to examine the effects of androgen deprivation during the acute response, during the period of apparent quiescence, and during the emergence of highly proliferative, androgen-independent prostate cancer cells (LNCaP-AI).
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:To decipher the contribution of WDR77 and p53 to androgen-responsive gene expression, effect of siRNA-mediated silencing of WDR77 and p53 on expression of androgen-dependent genes was studied. Human LNCaP prostate cancer cells were transfected with individual siRNA SmartPools targeting WDR77 or p53 or a non-targeting siRNA SmartPool. Forty-two hours after transfection, cells were treated with synthetic androgen R1881 (5nM) or vehicle. Three biological replicates were generated per treatment group. Forty-eight hours later, total RNA was isolated and processed for Illumina oligoarray analysis.
Project description:In castration-resistant prostate cancer (CRPC), clinical response to androgen receptor (AR) antagonists is limited mainly due to AR-variants expression and restored AR signaling. The metabolite spermine is most abundant in prostate and it decreases as prostate cancer progresses, but its functions remain poorly understood. Here, we show spermine inhibits full-length androgen receptor (AR-FL) and androgen receptor splice variant 7 (AR-V7) signaling and suppresses CRPC cell proliferation by directly binding and inhibiting protein arginine methyltransferase PRMT1. Spermine reduces H4R3me2a modification at the AR locus and suppresses AR binding as well as H3K27ac modification levels at AR target genes. Spermine supplementation restrains CRPC growth in vivo. PRMT1 inhibition also suppresses AR-FL and AR-V7 signaling and reduces CRPC growth. Collectively, we demonstrate spermine as an anticancer metabolite by inhibiting PRMT1 to transcriptionally inhibit AR-FL and AR-V7 signaling in CRPC, and we indicate spermine and PRMT1 inhibition as powerful strategies overcoming limitations of current AR-based therapies in CRPC.
Project description:Identification of the molecular changes that promote viability and metastatic behaviour of prostate cancer cells is critical for the development of improved therapeutic interventions for prostate cancer. Stat5a/b and Stat3 are both constitutively active in locally-confined and advanced prostate cancer, and both transcription factors have been reported to be critical for the viability and growth of prostate cancer cells. We used microarrays to compare gene expression profiles regulated by Stat5a/b vs. Stat3 in human prostate cancer cells. DU145 and CWR22Rv1 human prostate cancer cells were transfected with Stat3 siRNA, Stat5a/b siRNA or scramble siRNA as control. After 48 h, the cells were harvested and total RNA was prepared for Affymetrix microarrays.
Project description:Following androgen ablation treatment for advanced prostate cancer, almost all men relapse after a period of initial response to therapy, which eventually is life threatening. We have previously found that purine-rich element binding protein, PUR alpha, was significantly repressed in androgen-independent prostate cancer cell lines in comparison to an androgen-dependent line. Moreover, over-expressing PURa in androgen-independent prostate cancer cells attenuated their cell proliferation. The aim of the studies described here was to uncover some of the mechanisms by which over-expression of PURa attenuates cell proliferation. A set of common genes induced by over-expressing PURa both in PC3 and LNCaP cells was analyzed by DNA microarray. The results were then validated utilizing quantitative reverse transcription-PCR. Using a 5.3-kb region of the PSA promoter containing androgen response elements, the participation of PURa in androgen regulated gene expression was determined. Genes involved in stress response and cell differentiation were induced in cells over-expressing PURa. Some of the genes that are targets of androgen regulation are also induced. Most strikingly, ectopic expression of PURa induced transcriptional activity of the 5.3-kb PSA promoter containing androgen response elements, without androgen stimulation. Based upon the consideration that some of the genes involved in cell stress and differentiation are also regulated by androgens our data suggest that PURa shares some common pathway regulated by the androgen receptor. These findings suggest that regulation of PURa expression in prostate cancer cells may serve as a therapeutic target for hormone refractory prostate cancer.