Although NCOA1 is known to promote breast cancer metastasis through working with multiple transcription factors to upregulate the expression of Twist1, ITGA5, CSF-1, SDF1 and CXCR4, the role of NCOA1 in breast tumor angiogenesis has not been investigated.
In agreement with this phenotype, SRC-1 expression positively correlated with integrin α(5) (ITGA5) expression in estrogen receptor-negative breast tumors whereas SRC-1 deficiency decreased ITGA5 expression.
Differential recruitment of coregulator proteins steroid receptor coactivator-1 and silencing mediator for retinoid and thyroid receptors to the estrogen receptor-estrogen response element by beta-estradiol and 4-hydroxytamoxifen in human breast cancer.
Using quantitative RT-PCR, we, therefore, measured the levels of transcripts encoding these coregulators, as well as the corepressor SMRT, and the coactivator SRC-1, in a small cohort of tamoxifen-resistant and sensitive breast tumors.