ESR1 and breast cancer: Furthermore, in MDA-MB-468, triple negative basal type breast cancer cell line mutant TP53 was shown to stabilize the DNMT1-MeCP2-HDAC1 complex leading to suppression of ESR1, survivin and cdc25c gene expression via hypermethylation (Estève et al. 2005; Arabsolghar et al. 2013).