Project description:Activation of Signal Transducer and Activator of Transcription 3 (STAT3) is common in prostate cancers. STAT3 may induce cell proliferation and resistance to apoptosis, as well as promote tumor angiogenesis, invasion, and migration by activating gene expression. Many STAT3-dependent transcriptional responses are mediated through protein-protein interactions that involve the amino-terminal domain (N-domain). In this study, we found that inhibition of the STAT3 N-domain using novel inhibitor ST3-Hel2A-2 induces apoptotic death in prostate cancer cells. The cell death was accomponied by robust activation of pro-apoptotic gene. Using chromatin immunoprecipitation and tiling human promoter arrays (ChIP-chip), we have defined genome-wide targets of STAT3 in DU145 prostate cancer cells. We found that upregulated pro-apoptotic genes were bound by STAT3 in prostate cancer cells, and that STAT3 binding was decreased following inhibition of the STAT3 N-domain. STAT3 siRNA knockdow confirmed specificity of STAT3 binding and changes in gene expression. DU145 cells were treated with STAT3 siRNA or scrambled siRNA for 48hr. Total RNA has been extracted and prepared for hybridization on Affymetrix HG-U133A 2.0 arrays.
Project description:Expression data from DU145 cells treated with ST3-Hel2A-2 STAT3 N-domain inhibitor coupled to analysis of genome-wide STAT3 binding sites
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.