Skip to main content
Figure 3 | BMC Cancer

Figure 3

From: Steroid receptor coactivator 1 deficiency increases MMTV-neu mediated tumor latency and differentiation specific gene expression, decreases metastasis, and inhibits response to PPAR ligands

Figure 3

Coactivator overexpression induces resistance to the anti-proliferative effects of PPAR and RXR ligands. (A, B) Expression of SRC-1 and CBP mRNAs in stable MCF7 and MDA-MB-468 clones is shown by quantitative RT-PCR. Coactivator expression is normalized to levels of β-actin mRNA. Error bars indicate SEM of 3 independent experiments. (C) Expression of SRC-1 and CBP proteins in human breast cancer clones. (D, E) MCF7 or MDA-MB-468 cells overexpressing SRC- 1 were treated with 100 nM AGN194204, 100 μM ciglitazone (cig) or clofibrate (clo), or vehicle for 16 hours followed by chromatin immunoprecipitation (ChIP) with antibodies to SRC1, CBP, or acetylated histone H3 (acH3). Nuclease digested DNA from treated cells was amplified to detect nucleosomal loading of the EGFR promoter. The proximal promoter region was amplified by quantitative PCR and amplification products normalized to input DNA. (F, G) MCF7 or MDA-MB-468 cells overexpressing CBP were treated with 100 nM AGN194204, 100 μM ciglitazone (cig) or clofibrate (clo), or vehicle for 16 hours followed by chromatin immunoprecipitation (ChIP) with antibodies to SRC1, CBP, or acetylated histone H3 (acH3). Nuclease digested DNA from treated cells was amplified to detect nucleosomal loading of the EGFR promoter. The promoter region was amplified by quantitative PCR. (H) MCF7 (left panel) and MDA-MB-468 (right panel) cells stably expressing SRC-1 or CBP were treated with 100 μM clofibrate (clo) or ciglitazone (cig), 100 nM AGN194204, or vehicle for 16 hours. Protein extracts from these treated cells were subjected to western blotting using cell cycle antibodies indicated at left. These experiments were performed 3 times with similar results. (I) SRC-1 and CBP overexpression inhibits casein protein levels in human breast cancer cells. Protein extracts from MCF7 and MDA-MB-468 clones expressing SRC-1 or CBP or control vector were subjected to western blotting using antibodies indicated at left.

Back to article page