High expression of ubiquitin-conjugating enzyme E2C (UBE2C) correlates with relapse in luminal A breast cancer

Abstract

Human ubiquitin-conjugating enzyme E2C (UBE2C) is a member of the E2 ubiquitin-conjugating enzyme family. UBE2C expression is elevated in various human cancers, which has been reported to promote cancer progression through destruction of mitotic cyclins. However, the molecular mechanism underlying the role of UBE2C in the relapse of breast cancer remains largely undefined. Recently, we identified UBE2C as novel prognostic factors through a clinical follow-up study in relapsed luminal A breast cancer patients. To further understand the molecular basis of UBE2C in tumor progression, the function and mechanism of UBE2C in luminal A breast cancers were investigaated in the present study. The results demonstrated that UBE2C promote the proliferation and migration of luminal A breast cancer cells. Furthermore, treatment of cells with UBE2C-specific small interfering RNA (siRNA) showed a synergistic effect with Tamoxifen on inhibiting cell growth. Moreover, UBE2C was induced by estradiol, and its level correlated with tumor cell growth. Collectively, this study shows that UBE2C is a transcription target of estrogen receptor (ER)-alpha and contributes to the abnormal tumor progression in ER positive breast cancers. Therefore, UBE2C may be a candidate marker for the diagnosis of luminal A breast cancer patients as well as a new therapeutic target in combination therapy with Tamoxifen.