Chromatin targets of androgen receptor and PIAS1 in molecular apocrine breast cancer cells [ChIP-seq]. Homo sapiens

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. Overall design: All ChIP-seq samples were collected from cells treated with 10 nM R1881 (synthetic androgen methyltrienolone) for 2 h. In addition, AR ChIP-seq samples were collected from cells exposed to control siRNA (siNON, Dharmacon Non-targeting pool) or PIAS1 siRNA (siPIAS1, Dharmacon ON-TARGETplus SMARTpool for human PIAS1). IgG sample was collected from siNON and siPIAS1 cells and used as background control. Biological duplicate samples of the AR, PIAS1 and single IgG ChIP-seq samples were analyzed by using Solexa/Illumina 1.5.