ABSTRACT: SRC-1 (NCOA1) is a steroid receptor coactivator that has been associated with various aspects of the progression of breast cancer disease such as tamoxifen resistance, metastasis, cell proliferation and invasiveness. In a tamoxifen resistant breast cancer cell line (LY2), SRC-1 has been found to interact with the developmental transcription factor HoxC11. ChIP-sequencing of HoxC11 in LY2 cells shows where the transcription factor binds throughout the genome. LY2 cells were treated with either tamoxifen or vehicle and immunoprecipitated with anti-Hoxc11
Project description:We profile the binding of Steroid Receptor Co-activator (SRC1) in LY2 cells, a tamoxifen-resistant cell line, in the presence and absence of tamoxifen using ChIP-sequencing technology. The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid-independent tumour. The p160 steroid coactivataor protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors, drives this tumour adaptability. Here, using discovery studies, we identify ADAM22, a non-protease member of the ADAMs family, as a direct, ER-independent target of SRC-1. Molecular, cellular and in vivo studies confirmed SRC-1 as a regulator of ADAM22. At a functional level, a role for ADAM22 in cellular migration and differentiation was observed. In vivo data from a mouse xenograft model indicated that ADAM22 expression was higher in 4-OHT-treated endocrine-resistant tumours than in tumours derived from isogenic, sensitive cells. Furthermore, in breast cancer patients, ADAM22 expression is an independent predictor of poor disease free survival. SRC-1 can function as a molecular switch which converts a steroid-responsive tumour to a steroid-resistant tumour. The ER-independent SRC-1 target ADAM22 is a potential drug target and a companion predictive biomarker in the treatment of endocrine-resistant breast cancer. Examination of SRC-1 binding in LY2 cells in the presence or absence of tamoxifen treatment. 2 replicates each.
Project description:The steroid co-activator protein SRC-1 plays an important role in endocrine therapy resistant breast cancer. Its expression is associated with large high grade tumours, HER2 positivity, disease recurrence and resistance to endocrine therapy. While SRC-1 typically functions to activate gene expression, some evidence has pointed towards a potential role in repression. This study looks into the effects of a stable knockdown of SRC-1 in a tamoxifen resistant cell line, LY2, and the effects of this knock down on the methylation landscape. Overall design: We report the MeDIP-sequencing of tamoxifen treated LY2 breast cancer cells treated with non-targeting shRNA or SRC-1 (NCOA1) targeting shRNA and examine the methylation differences.
Project description:The steroid co-activator protein SRC-1 plays an important role in endocrine therapy resistant breast cancer. Its expression is associated with large high grade tumours, HER2 positivity, disease recurrence and resistance to endocrine therapy. SRC-1's role in affecting the transcriptome of the breast cancer endocrine resistant setting is uncovered through this RNA-seq analysis of LY2 cells grown with or without the presence of SRC-1 Overall design: We report the RNA-sequencing of tamoxifen treated LY2 breast cancer cells treated with non-targeting shRNA or SRC-1 (NCOA1) targeting shRNA and examine the gene expression differences.
Project description:ER-dependent gene expression was investigated in the LY2 endocrine resistant cell line by treatment with ICI 182780. Cells were steroid depleted for 3 days prior to treatment with ICI for 6 hours. Four biological replicates were processed and analysed.
Project description:The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid independent tumour. The p160 steroid coactivator protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors drives this tumour adaptability. Here, using discovery studies we identify ADAM22, a non-protease member of the ADAMs family, as a direct target of SRC-1, independent of estrogen receptor(ER). Molecular, cellular, in vivo and clinical studies confirmed SRC-1 as a regulator of ADAM22 and established a role for ADAM22 in endocrine resistant tumour progression. ADAM22 has the potential to act as a therapeutic drug target and a companion predictive biomarker in the treatment of endocrine resistant breast cancer. 14 samples representing 4 conditions were analysed. Samples were transfected with either a siRNA targetting SRC1 or a control scrambled siRNA. Samples were subject to tamoxifen treatment or untreated.
Project description:We futher characterized genome-wide chromatin accessibility of WT and SRC-2-/- mouse liver at CT10 through DNase-Seq. In addition,chromatin accessibility was significantly reduced in SRC-2-/- mouse liver compared to WT mice at CT10. DNase-Seq was carried out in WT and SRC-2-/- mice in liver at CT10 using two doses of DNaseI.
Project description:To assess the global effects of HOXC11 in endocrine resistant breast cancer cells we performed RNA-seq on LY2 cells which were transfected with either siRNA targeting HOXC11 (siHOXC11) or a scrambled negative control siRNA (scrHOXC11) in the presence of 4-OH-tamoxifen (10-8M). Knockdown was verified by Taq-man qRT-PCR prior to library preparation. RNA (10µg) was extracted using an Oligotex mRNA kit (Qiagen) as per manufacturer’s instructions (n=4). RNA was reverse transcribed followed by mRNA library preparation and sequencing based on a protocol outlined by Wilhelm et al., 2010. Sequencing was performed on an Illumina Genome Analyzer II (GAII) (54 million reads per sample on average). Overall design: Silencing of HOXC11 in tamoxifen resistant LY2 cells to identify putative HOXC11 target genes.
Project description:We generated genome-wide cistromes of BAF180 subunit of the SWI-SNF chromatin remodeling complex in mouse liver at CT10 and CT22. In addition, we performed ChIP-Seq analysis on REV-ERBα in WT and SRC-2-/- mouse liver at CT10. We found circadian oscilation of BAF180 chromatin recruitment in mouse liver with peak recruitment at CT22 and nadir at CT10. Further,REV-ERBα chromatin recruitment was significantly reduced in SRC-2-/- mouse liver compared to WT mice at CT10. ChIP-Seq for BAF180 was performed in WT mice liver at CT10 and CT22 using two different antibodies. ChIP-Seq for REV-ERBα was performed in WT and SRC-2-/- mice in liver at CT10 with biological replicates.
Project description:The androgen receptor (AR) is overexpressed and hyperactivated in human castration-resistant prostate cancer (CRPC). However, the determinants of AR overexpression in CRPC are poorly defined. Here we show that retinoic acid receptor–related orphan receptor γ (ROR-γ) is overexpressed and amplified in metastatic CRPC tumors, and that ROR-γ drives AR expression in the tumors. ROR-γ recruits nuclear receptor coactivator 1 and 3 (NCOA1 and NCOA3, also known as SRC-1 and SRC-3) to an AR–ROR response element (RORE) to stimulate AR gene transcription. ROR-γ antagonists suppress the expression of both AR and its variant AR-V7 in prostate cancer (PCa) cell lines and tumors. ROR-γ antagonists also markedly diminish genome-wide AR binding, H3K27ac abundance and expression of the AR target gene network. Finally, ROR-γ antagonists suppressed tumor growth in multiple AR-expressing, but not AR-negative, xenograft PCa models, and they effectively sensitized CRPC tumors to enzalutamide, without overt toxicity in mice. Taken together, these results establish ROR-γ as a key player in CRPC by acting upstream of AR and as a potential therapeutic target for advanced PCa. A total of 16 samples were analyzed in this study. The study included one cell line C4-2B. C4-2B cells were cultured in medium containing vehicle control or SR2211 (5 µM) for 24 hours, cells then were collected for ChIP seq assay