CCNB1 is a prognostic biomarker for ER+ breast cancer.

Identification of effective prognostic biomarkers and targets are of crucial importance to the management of breast cancer. CCNB1 (also known as CyclinB1) belongs to the highly conserved cyclin family and is significantly overexpressed in various cancer types. In this study, we demonstrated that CCNB1 had significant predictive power in distant metastasis free survival, disease free survival, recurrence free survival and overall survival of ER+ breast cancer patients. We also found that CCNB1 was closely associated with hormone therapy resistance. In addition, gene set enrichment analysis (GSEA) revealed that its expression was positively associated with genes overexpressed in endocrine therapy resistant samples. Finally, using CCNB1-Drug interaction network, we demonstrated the interactions between CCNB1 and several available cancer drugs. Overall, we suggest that CCNB1 is a biomarker for the prognosis of ER+ breast cancer and monitoring of hormone therapy efficacy. It is also a promising target for developing new strategies to prevent or even reverse hormone therapy resistance. Moreover, CCNB1 expression may help to monitor hormone therapy and to direct personalized therapies. Nevertheless, in vivo and in vitro experiments and multi-center randomized controlled clinical trials are still needed before its application in clinical settings.