Project description:uSTAT transcriptional program HPC7 cells were fixed with either 1% formaldehyde for 10 mins. Chromatin was isolated, sonicated for 7 mins (30 sec on, 30 sec off), and specific antibodies were used to pull down the transcription factors of insterest after a pre-clearing step. Chromatin was washed, de-crosslinked, amplified, size selected by gel purification and sequenced.
Project description:We aimed to investigate the transcriptional program associated with pimonidazole staining in prostate cancer. A pimonidazole gene signature was identified that showed positive correlation to Ki67 labeling index, indicating increased proliferation in pimonidazole positive tumors. A positive correlation to clinical tumor stage and presence of lymph node metastasis was also found, consistent with associations between pimonidazole staining and clinico-pathological parameters. Moreover, the gene signature was associated with high Gleason score in a validation cohort of 59 patients and showed prognostic impact independent of Gleason score and other clinical markers in a watchful waiting validation cohort of 281 patients. Our work reveals the molecular basis of an aggressive prostate cancer phenotype reflected by pimonidazole staining, and suggests that genes involved in proliferation, DNA repair and hypoxia response contribute to this phenotype. We combined pimonidazole immunohistochemistry data and expression profiles to identify transcriptional program activated in pimonidazole positive tumors. Whole-genome gene expression profiles were determined in tumor biopsies from an investigation cohort of 46 patients, where 39 patients had received pimonidazole prior to surgery. Gene ontology analysis of 1046 genes upregulated in pimonidazole positive tumors, as defined by a staining fraction above 10%, showed significant enrichment of the biologic processes cell cycle, translation and cellular response to stress. Gene set analysis based on this result identified gene expressions in proliferation, DNA repair and hypoxia response as major parts of the transcriptional program associated with pimonidazole staining. Gene expression data of four prostate cancer cell lines were used to generate hypoxia response gene sets for this analysis. A signature of the 32 most essential genes in the program was constructed and shown to be associated with prostate cancer aggressiveness in two independent validation cohorts.
Project description:We profiled Myc binding in a normal breast cell-line (MCF10A) under basal conditions after ectopic expression of Myc. We showed that ectopic Myc expression increases tumour formation in vivo and in vitro. We then profiled genome-wide Myc binding using Agilent promoter arrays in MCF10A cells expressing wild-type and ectopic Myc. We show that Myc binds to a greater number of spots in wild-type than in Myc cells, but that some targets are unique to each condition. This SuperSeries is composed of the following subset Series: GSE13749: Genome-wide characterization of the transcriptional program of Myc-dependent transformation, ChIP-chip GSE14263: Genome-wide characterization of the transcriptional program of Myc-dependent transformation, expression study Refer to individual Series
Project description:We aimed to investigate the transcriptional program associated with pimonidazole staining in prostate cancer. A pimonidazole gene signature was identified that showed positive correlation to Ki67 labeling index, indicating increased proliferation in pimonidazole positive tumors. A positive correlation to clinical tumor stage and presence of lymph node metastasis was also found, consistent with associations between pimonidazole staining and clinico-pathological parameters. Moreover, the gene signature was associated with high Gleason score in a validation cohort of 59 patients and showed prognostic impact independent of Gleason score and other clinical markers in a watchful waiting validation cohort of 281 patients. Our work reveals the molecular basis of an aggressive prostate cancer phenotype reflected by pimonidazole staining, and suggests that genes involved in proliferation, DNA repair and hypoxia response contribute to this phenotype.