MicroRNA Regulates Estrogen Receptor Alpha in Breast Cancer Metastasis

Breast cancer (BCa) is a common endocrine disorder among postmenopausal women and estradiol (E2) known causative agent for metastasis. During previous decade, tiny microRNAs (miRNAs) become a potential mediator of tumor suppressor or tumorigenic factor. Numerous miRNA regulates nuclear receptor ERα under the influence of estradiol (E2) such as miR101, miR-21 whereas miR145, miR-29a, miR-206, let-7 potentiates ERα proliferating activity. MiR-221/222 have established in hormone refractory condition after long exposure of Selective Estrogen Receptor Modulators (SERMs) or Selective Estrogen Receptor Down Regulator (SERDs). The target genes and the role of miRNAs in ERα mediated tumor progression is a challenging area of research that will open new clinical values as novel biomarkers in diagnosis and therapy.