BAP31 promotes breast cancer progression by interaction with SERCA2

Abstract

Abstract Background B-Cell receptor-associated protein 31 (BAP31) is a resident chaperone protein in the endoplasmic reticulum. It was observed herein that a higher expression of BAP31 mRNA was associated with a worse prognosis in breast cancer patients. Methods Breast cancer cells and normal breast tissue cells were used to confirm how BAP31 influences the progress of breast cancer both in vivo and vitro. Western blots and qRT-PCR assays supported the changes. Results Depletion of BAP31 in breast cancer cells increased apoptosis and decreased the capacities of proliferation, colony formation and invasion. BAP31 was observed to be associated with SERCA2, a sarco/endoplasmic reticulum Ca2+-ATPase. Depletion of BAP31 decreased endoplasmic reticulum Ca2+ storage with resultant ER stress and breast cancer cell death; which required BAP31 association with SERCA2 . Conclusion Hence, these findings have demonstrated that BAP31 enhanced the viability, oncogenicity and motility of breast cancer cells by modulation of endoplasmic reticulum Ca2+ homeostasis. Thus, BAP31 promotes progression of breast cancer.