Abstract
Ring finger protein 6 (RNF6), a member of E3 ubiquitin ligases, plays a potential role as a tumour promoter in numerous carcinomas. However, the role and expression of RNF6 in breast cancer (BC) remains to be elucidated. The present study showed that RNF6 upregulation was detected in BC tissues and was associated with short survival in patients with BC. Multivariate analysis also revealed that RNF6 overexpression is an independent predictor for poor outcome of patients with BC. Furthermore, migration and metastasis assay indicated that RNF6 silencing significantly inhibited the invasion and migration of BC cells in vivo and in vitro, and RNF6 suppression decreased YES-associated protein (YAP) expression. RNF6 promoted the metastatic ability of BC cells via YAP. Mechanistically, RNF6 interacts with mammalian STE20-like protein kinase 1 (MST1), a key factor that regulates YAP, and promoted its ubiquitination and degradation. Additionally, RNF6 regulated YAP signalling by promoting ubiquitination and degradation of MST1 in BC. Taken together, these data may highlight a role of RNF6 in BC, which could serve as a valuable prognostic indicator and potential therapeutic target for patients with BC.