Profiling of histone modifications in GATA3 ZnFn2 mutant cells with progesterone treatment
Ontology highlight
ABSTRACT: R330fs GATA3 mutant disrupts the progesterone network in T47D cells. We mapped active histone marks (H3K4me1 and H3K27ac) and repressive histone mark (H3K27me3) in the T47D GATA3 mutant cells after progesterone treatment. Control (vehicle) data has been posted under the accession number GSE130703.
Project description:A pioneer transcription factor, GATA3, is one of the most frequently mutated genes in breast cancer, yet the impact of these mutations is largely unknown. We generated a GATA3 mutant cell line (T47D wt/R330fs) by CRISPR. Mutation of one allele of GATA3 led to loss of binding and decreased expression at a subset of genes, including Progesterone Receptor. At other loci, associated with epithelial to mesenchymal transition, gain of binding at a novel sequence motif correlated with increased gene expression. Our results illuminate tumor-promoting functions of specific GATA3 mutations in breast cancer.
Project description:The transcription factor GATA3 is a favorable prognostic indicator in estrogen receptor-M-NM-1 (ERM-NM-1)-positive breast tumors in which it participates with ERa and FOXA1 in a complex transcriptional regulatory program driving tumor growth. Paradoxically, GATA3 mutations are frequent in breast cancer and have been classified as drivers. To elucidate the contribution(s) of GATA3 alterations to oncogenesis, we studied two breast cancer cell lines, MCF7, which carries a heterozygous frameshift mutation in the second zinc finger of GATA3, and T47D, wild-type at this locus. Heterozygosity for the truncating mutation conferred protection from regulated turnover of GATA3, ERa and FOXA1 following estrogen stimulation. Thus, mutant GATA3 uncouples protein-level regulation of master regulatory transcription factors from hormone action. Consistent with increased protein stability, ChIP-seq profiling identified stronger accumulation of GATA3 in cells bearing the mutation, albeit with a similar distribution across the genome. We propose that this specific, cancer-derived mutation in GATA3 deregulates physiologic protein turnover, stabilizes GATA3 binding across the genome and modulates the response of mammary epithelial cells to hormone signaling, thus conferring a selective growth advantage. Genome-wide mapping of GATA3 in two cell lines. There were two biological replicates and unchipped (input) DNA was used as reference.
Project description:The transcription factor GATA3 is a favorable prognostic indicator in estrogen receptor-α (ERα)-positive breast tumors in which it participates with ERa and FOXA1 in a complex transcriptional regulatory program driving tumor growth. Paradoxically, GATA3 mutations are frequent in breast cancer and have been classified as drivers. To elucidate the contribution(s) of GATA3 alterations to oncogenesis, we studied two breast cancer cell lines, MCF7, which carries a heterozygous frameshift mutation in the second zinc finger of GATA3, and T47D, wild-type at this locus. Heterozygosity for the truncating mutation conferred protection from regulated turnover of GATA3, ERa and FOXA1 following estrogen stimulation. Thus, mutant GATA3 uncouples protein-level regulation of master regulatory transcription factors from hormone action. Consistent with increased protein stability, ChIP-seq profiling identified stronger accumulation of GATA3 in cells bearing the mutation, albeit with a similar distribution across the genome. We propose that this specific, cancer-derived mutation in GATA3 deregulates physiologic protein turnover, stabilizes GATA3 binding across the genome and modulates the response of mammary epithelial cells to hormone signaling, thus conferring a selective growth advantage.
Project description:Anlaysis of the differential gene expression between T47D cells expressing wild type (WT) progesterone receptor isoform B (PR) or SUMOylation-deficient PR molecules. Total RNA obtained from T47D breast cancer cells that express either WT PR-B or mutant PR-B (K388R, SUMO-deficient), treated with or without synthetic PR ligand R5020 for 6 h.
Project description:T47D cells were starved 0% FCS for 24 hours. Following starvation PARG was inhibited via the use of Tannic Acid (TA) and the gene expression in response to progesterone studied. Cells were stimiulated with R5020 for 1 or 6 hours. NUDIX5 was reduced in T47D cells 48 hours prior to hormone induction via the use of NUDIX5 specific siRNA. Progesterone response and gene expression changes were analyzed as described above following 6 hours of R5020.
Project description:Anlaysis of the differential gene expression between T47D cells expressing wild type (WT) progesterone receptor isoform B (PR) or SUMOylation-deficient PR molecules. Total RNA obtained from T47D breast cancer cells induced (with AP21967) to express either iWT PR-B or mutant PR-B (iK388R, SUMO-deficient), treated with or without synthetic PR ligand R5020 for 6 h. Each sample had 1 replicate.
Project description:Estrogen Receptor (ER) is a steroid hormone receptor that regulates epithelial genes in breast cancer. ER forms a regulatory network with the other transcription factors, FOXA1 and GATA3. GATA3 is known to be capable of specifying chromatin localization of FOXA1 and ER. GATA3 has been identified as one of the most frequently mutated genes in breast cancer. However, how GATA3 mutations impact this transcriptional network is unknown. Here we investigate the function of one of the recurrent patient-derived GATA3 mutations (R330fs) for this regulatory network. Genomic analysis indicates that the R330fs mutant can disrupt the cooperative action of ER, FOXA1, and GATA3, and induce chromatin relocalization of these factors. Relocalizations of ER and FOXA1 are associated with altered chromatin architectures leading to differential gene expression in the GATA3 mutant cells. These results suggest the active role of GATA3 mutants in ER positive breast tumors.
Project description:T47D cells were starved 0% FCS for 24 hours. Following starvation PARP1 was inhibited via the use of 3AB and the gene expression in response to progesterone studied. Cells were stimiulated with R5020 for 1 or 6 hours.