Estrogen receptor β2 (ERβ2)-mediated upregulation of hsa_circ_0000732 promotes tumor progression via sponging microRNA-1184 in triple-negative breast cancer (TNBC)

The role of estrogen receptor β (ERβ) in the pathogenesis and development of breast cancer (BC) is controversial, and it is currently considered to play contradictory roles in different phenotypes. ERβ2 is thought to promote the BC process, but its role in triple-negative breast cancer (TNBC) has not been reported.In this study, we collected tumor tissues from 15 patients with TNBC and obtained a variety of TNBC cell lines as research objects. The plasmid vectors and RNA interference techniques were used to change the level of target genes in cells, quantitative PCR and Western Blots were used to detect gene expression levels, CCK-8 and EdU assay were used to detect cell growth, and Transwell was used to detect cell migration and invasion. Dual-luciferase gene reports and RNA immunoprecipitation (RIP) were used to verify gene targeting relationships.ERβ2 was up-regulated in TNBC tissues and promoted the growth, migration, and invasion of TNBC cells. ERβ2 regulated hsa_circ_0000732 expression by binding to SCARF1 promoter. Knockdown of hsa_circ_0000732 inhibited TNBC cell proliferation, migration, and invasion by upregulating miR-1184.Our present study found that ERβ2 is upregulated in some TNBC cells and promotes TNBC cell growth, migration and invasion by regulating hsa_circ_0000732 targeting miR-1184. The special role of ERβ2 in TNBC may be the breakthrough of a targeted treatment strategy for TNBC.