Project description:Liver receptor homologue 1 (LRH-1) is an orphan nuclear receptor which has been implicated in the growth and development of breast, pancreatic and colorectal cancers (CRC). In order to identify novel LRH-1-regulated genes in CRC cells, we performed gene expression profiling following siRNA-mediated LRH-1 silencing in the CRC cell line HT29.
2015-10-01 | GSE65814 | GEO
Project description:Identification of Liver Receptor Homologue-1 (LRH-1)-regulated genes in colorectal cancer cells
Project description:Liver receptor homologue 1 (LRH-1) is an orphan nuclear receptor which has been implicated in the growth and development of breast, pancreatic and colorectal cancers (CRC). In order to identify novel LRH-1-regulated genes in CRC cells, we performed gene expression profiling following siRNA-mediated LRH-1 silencing in the CRC cell line HCT116.
Project description:Estrogen receptor α (ERα) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, is ERα-regulated in breast cancer cells. Further, LRH-1 stimulates proliferation and promotes motility and invasion of breast cancer cells. To determine the mechanisms of LRH-1 action in breast cancer cells, we carried out gene expression microarray analysis following siRNA-mediated LRH-1 knockdown. Interestingly, gene ontology (GO) category enrichment analysis of the genes differentially regulated in the presence or absence of LRH-1 identified estrogen responsive genes as the most highly enriched GO categories. To further define LRH-1 target genes, we performed chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1. Remarkably, ChIP-seq showed LRH-1 binding at many ERα binding sites. Analysis of select binding sites confirmed regulation of ERα-regulated genes by LRH-1 through binding to estrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 over-expression stimulated ERα recruitment, whilst LRH-1 knockdown reduced ERα recruitment to ERα binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERα target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERα at estrogen response elements controls the expression of estrogen-responsive genes.
Project description:Estrogen receptor M-NM-1 (ERM-NM-1) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, is ERM-NM-1-regulated in breast cancer cells. Further, LRH-1 stimulates proliferation and promotes motility and invasion of breast cancer cells. To determine the mechanisms of LRH-1 action in breast cancer cells, we carried out gene expression microarray analysis following siRNA-mediated LRH-1 knockdown. Interestingly, gene ontology (GO) category enrichment analysis of the genes differentially regulated in the presence or absence of LRH-1 identified estrogen responsive genes as the most highly enriched GO categories. To further define LRH-1 target genes, we performed chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1. Remarkably, ChIP-seq showed LRH-1 binding at many ERM-NM-1 binding sites. Analysis of select binding sites confirmed regulation of ERM-NM-1-regulated genes by LRH-1 through binding to estrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 over-expression stimulated ERM-NM-1 recruitment, whilst LRH-1 knockdown reduced ERM-NM-1 recruitment to ERM-NM-1 binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERM-NM-1 target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERM-NM-1 at estrogen response elements controls the expression of estrogen-responsive genes. MCF-7 cells were transfected with LRH-1 siRNA #2, #3, or with a non-targeting siRNA (siControl) for 72 hours. Following assessment of RNA integrity, four biological replicates for each siRNA treatment were used for microarray analysis.
Project description:The ovarian reserve of follicles comprises all oocytes for lifetime fertility and is depleted by progressive activation. The orphan nuclear receptor liver receptor homolog 1 (LRH-1; Nr5a2) is essential for ovulation, but its role in the early stages of follicular development is not known. We therefore developed a model of conditional depletion of LRH-1 from early postnatal ovaries (postnatal day 4) and performed RNAsequencing to identify LRH-1 regulated genes during the earliest stages of follicular activation.
Project description:To find candidate circRNAs and to unravel their molecular functions during colorectal cancer progression and during LDM topotecan chemotherapy, we utilized a xenograft mouse model based on the HT29.hCG.Luc colorectal cancer cell line (referred to as HT29) implanted into SCID mice. HT29 cells were injected into the spleen and primary tumors developed. Three mice served as control group while two mice served as LDM topotecan treated group. After another 4-6 weeks, liver metastasis can be detected and resected for further investigation. For a global view on miRNA changes, we performed miRNA-Seq from HT29 cells, primary tumors and liver metastases from control mice (C-PT and C-LM) and liver metastases from treated mice (T-LM).
Project description:Tumor characteristics are decisive in the determination of treatment strategy for breast cancer patients. Patients with estrogen receptor a(ERa)-positive breast cancer can benefit from long-term hormonal treatment. Nonetheless, the majority of patients will develop resistance to these therapies. Here, we investigated the role of the nuclear receptor liver receptor homolog-1 (LRH-1, NR5A2) in anti-estrogen (AE) sensitive and resistant breast cancer cells. We identified genome-wide LRH-1 binding sites using ChIP-seq, uncovering preferential binding to regions distal to transcriptional start sites (TSS). We further characterized these LRH-1 binding sites by integrating overlapping layers of specific chromatin marks, revealing that many LRH-1 binding sites are active and could be involved in long-range enhancer-promoter looping. Combined with transcriptome analysis of LRH-1 depleted cells, these results show that LRH-1 regulates specific subsets of genes involved in cell proliferation in AE-sensitive and AE-resistant breast cancer cells. Furthermore, the LRH-1 transcriptional program is highly associated with a signature of poor outcome and high-grade breast cancer tumors in vivo. Herein we report the genome-wide location and molecular function of LRH-1 in breast cancer cells and reveal its therapeutic potential for the treatment of breast cancers, notably for tumors resistant to treatments currently used in therapies. ChIP-seq examination of LRH-1 binding sites with specific chromatin marks in MCF7 breast cancer cells.
Project description:To find candidate circRNAs and to unravel their molecular functions during colorectal cancer progression and during LDM topotecan chemotherapy, we utilized a xenograft mouse model based on the HT29.hCG.Luc colorectal cancer cell line (referred to as HT29) implanted into SCID mice. HT29 cells were injected into the spleen and primary tumors developed. Three mice served as control group while two mice served as LDM topotecan treated group. After another 4-6 weeks, liver metastasis can be detected and resected for further investigation. For a global view on gene expression changes, we performed rRNA-depletion RNA-Seq from HT29 cells, primary tumors and liver metastases.