Genome-wide analysis of the effect of PIAS1 knockdown by siRNA on the androgen regulated gene programs
Ontology highlight
ABSTRACT: Analysis of PIAS1 co-regulation in the androgen signaling pathways in prostate cancer cell line. VCaP cells were exposed to control (siSCR) or PIAS1 (siPIAS1) targeted siRNA for 96h. After 16h of 100 nM testosterone (or without) treatment the total RNA was isolated, each treatment included three replicates.
Project description:The majority of breast cancer subtypes express androgen receptor (AR) in addition to estrogen receptor α (ERα). Depending on the breast cancer subtype androgen signaling has either stimulatory or inhibitory roles in breast cancer cell growth. We have mapped AR cistrome in ERα negative human molecular apocrine breast cancer MDA-MB453 cells and analyzed it in relation to the androgen-regulated transcriptome in the same cells. We have also examined the effect of silencing of the coregulator SUMO ligase PIAS1 on the androgen-regulated transcriptome and AR cistrome in MDA-MB453 cells. Our results show that the MDA-MB453 cells share with VCaP prostate cancer cells a core AR cistrome and target gene signature linked to cancer cell growth and that PIAS1 acts as an AR target gene-selective coregulator in MDA-MB453 cells. MDA-MB453 cells were transfected with control siRNA (siNON) or PIAS1 siRNA (siPIAS1) for 72 h and treated 16 h with 10 nM R1881 or vehicle (ethanol). Total RNA was isolated and biological triplicate samples were analyzed by microarray.
Project description:To study the importance of PIAS1 (protein inhibitor of activated STAT1) for the androgen-regulated transcriptome of VCaP prostate cancer cells, we silenced its expression by RNAi. Transcriptome analyses revealed that a subset of the androgen-regulated genes is significantly influenced, either activated or repressed, by PIAS1 depletion. The depletion also exposed a completely new set of genes to androgen regulation, suggesting that PIAS1 can mask genes from androgen receptor (AR). Pathway analyses of gene expression data suggest involvement of PIAS1 in VCaP cell proliferation. According to genome-wide ChIP-seq analyses, PIAS1 interacts with the AR on chromatin harboring also SUMO2/3, as androgen exposure multiplied the occupancy of PIAS1 in the chromatin, and resulted in nearly complete overlap with AR chromatin binding events. PIAS1 interacted also with pioneer factor FOXA1 in the chromatin. Our results strongly suggest that PIAS1 is a genuine chromatin-bound coregulator of AR which functions in a target gene selective fashion in prostate cancer cells.
Project description:Heat shock induces rapid modification of proteins with SUMO2/3. This study concentrated in charaterizing how these changes are reflected on SUMOylation of chromatin bound proteins, trancsription, and chromatin binding of SUMO ligase PIAS1. Comparison of chromatin SUMO2/3 modification pattern in non-stressed and heat shocked K562 and VCaP cells. All samples were done as biological replicates. In K562 cells, SUMO2/3 ChIP-seq was done in non-stressed (37C) and heat shocked (30min at 43C) cells. The effect of heat shock factor 1 (HSF1) to chromatin SUMOylation in HS was studied in HSF1 silenced (shHSF1) K562 cells (non-stressed vs. heat shocked) using scramble shRNA transfected cells as control (shSCR). SUMO2/3, SUMO ligase PIAS1,and RNA polymerase II binding in HS (30 min at 43C) and recovery from HS (1h at 37C after HS) was studied using ChIP-seq. Effect of PIAS1 for chromatin SUMOylation was studied in PIAS1 silenced (siRNA for PIAS1, siPIAS1) cells (non-stressed or heat shocked) using non-targeting siRNA transfected cells as a control (siNON). Effect of SUMOylation to chromatin binding of RNA polymerase II was studied in UBE2I silenced (siRNA for UBE2I) and control (non-targeting siRNA transfected, siNON) VCaP cells (non-stressed or heat shocked). Effect of transtription inhibition for chromatin SUMOylation was studied in TRP (triptolide; 1 micromolar, 3h) and DRB (5,6-Dichlorobenzimidazole 1-beta-D-ribofuranosidase; 100 micromolar, 3h) treated VCaP cells. GRO-seq was used to determine HS-induced changes in nascent transcription in K562 cells.
Project description:The majority of breast cancer subtypes express androgen receptor (AR) in addition to estrogen receptor α (ERα). Depending on the breast cancer subtype androgen signaling has either stimulatory or inhibitory roles in breast cancer cell growth. We have mapped AR cistrome in ERα negative human molecular apocrine breast cancer MDA-MB453 cells and analyzed it in relation to the androgen-regulated transcriptome in the same cells. We have also examined the effect of silencing of the coregulator SUMO ligase PIAS1 on the androgen-regulated transcriptome and AR cistrome in MDA-MB453 cells. Our results show that the MDA-MB453 cells share with VCaP prostate cancer cells a core AR cistrome and target gene signature linked to cancer cell growth and that PIAS1 acts as an AR target gene-selective coregulator in MDA-MB453 cells.
Project description:The majority of breast cancer subtypes express androgen receptor (AR) in addition to estrogen receptor a (ERa). Depending on the breast cancer subtype androgen signaling has either stimulatory or inhibitory roles in breast cancer cell growth. We have mapped AR cistrome in ERa negative human molecular apocrine breast cancer MDA-MB453 cells and analyzed it in relation to the androgen-regulated transcriptome in the same cells. We have also examined the effect of silencing of the coregulator SUMO ligase PIAS1 on the androgen-regulated transcriptome and AR cistrome in MDA-MB453 cells. Our results show that the MDA-MB453 cells share with VCaP prostate cancer cells a core AR cistrome and target gene signature linked to cancer cell growth and that PIAS1 acts as an AR target gene-selective coregulator in MDA-MB453 cells.
Project description:Androgen receptor (AR) is typically overexpressed in castration-resistant prostate cancer (CRPC). CRPC-derived VCaP cells display an excessive number of chromatin AR-binding sites (ARBs). This study analyzed direct transcription programs of the AR, the prevalence of AR enhancers and the transcriptional regulators involved in the regulation of at the enhancer regions. The analysis utilized global nuclear run-on sequencing (GRO-seq). The GRO-seq data were integrated with the ARB and VCaP cell-specific transcription factor-binding data. Androgen in 30 min activated and repressed transcription of a large number of genes including novel AR targets IGF-1 receptor and EGF receptor. GRO-seq analysis also revealed that only a fraction of the ARBs resides at functional enhancers. Activation of AR bound enhancers was most potent at the sites that also bound PIAS1, ERG and HDAC3. Our genome-wide data provide new insights how AR can directly control growth-signaling pathways in CPRC cells.
Project description:To study the effect of PIAS1 on transcriptional regulation, we establishedstable PIAS1 shRNA knockdown cells in breast cancer cell line MDA-MB231. By comparing the expression profiles of control vs PIAS1 knockdown cells, we can identify potential PIAS1 target genes involved in breast tumorigenesis.
Project description:To study the effect of PIAS1 on transcriptional regulation, we establishedstable PIAS1 shRNA knockdown cells in breast cancer cell line MDA-MB231. By comparing the expression profiles of control vs PIAS1 knockdown cells, we can identify potential PIAS1 target genes involved in breast tumorigenesis. MDA-MB231 Control shRNA and PIAS1 shRNA2 cells were cultured in DMEM plus 10% FBS (DMEM) or SCM for 30 h, and total RNA was used for microarray.
Project description:The Protein Inhibitor of Activated STAT 1 (PIAS1) is an E3 SUMO ligase that plays important roles in various cellular pathways, including STAT signaling, p53 pathway, and the steroid hormone signaling pathway. PIAS1 can SUMOylate PML (at Lys-65 and Lys-160) and PML-RARα promoting their ubiquitin-mediated degradation. Increasing evidence shows that PIAS1 is overexpressed in various human malignancies, such as prostate and lung cancers. To understand the mechanism of action of PIAS1, we developed a quantitative SUMO proteomic approach to identify potential substrates of PIAS1 in a system-wide manner. Our analyses enabled the profiling of 983 SUMO sites on 544 proteins, of which 204 SUMO sites on 123 proteins were identified as putative PIAS1 substrates. These substrates were found to be involved in different cellular processes, including transcriptional regulation, DNA binding and cytoskeleton dynamics. Further functional studies on Vimentin (VIM), a type III intermediate filament protein involved in cytoskeleton organization and cell motility, revealed that PIAS1 exerts its effects on cell migration and cell invasion through the SUMOylation of VIM at Lys-439 and Lys-445 residues. VIM SUMOylation was necessary for its dynamic disassembly, and cells expressing a non-SUMOylatable VIM mutant showed reduced levels of proliferation and migration. Our approach not only provides a novel strategy for the identification of E3 SUMO ligase substrates, but also yields valuable biological insights into the unsuspected role of PIAS1 and VIM SUMOylation on cell motility.
Project description:Heart diseases are as most leading causes of morbidity and mortality in the world. One of the promising approaches to cure these diseases is cell therapy using endogenous cardiac precursor cells resident in heart tissues. These cells are isolated from heart biopsies, cultured and passaged to reach to the desirable cell count necessary for transplantation. The process of cell propagation and subsequent passages may cause gene expression alteration unsuitable and dangerous for cell therapy; so in our study, we analyzed whole genome expression using microarray technology to compare expressed transcripts in 4 passages 6, 9, 12 and 15. There were 4 different passage samples (6, 9, 12, and 15) each stage with three replicates. Replicates for passage 6 were determied as control group and the data was analyzed compaired to this passage.