Abstract: Objective To investigate the relationship between mitochondrial calcium uniporter regulator 1（MCUR1） and the prognosis of ovarian cancer patients，and the effect of MCUR1 on the proliferation and apoptosis of ovarian cancer cells as well as its possible mechanism. Methods The data of 372 ovarian cancer patients were downloaded from the Cancer Genome Atlas （TCGA） database. The Kaplan-Meier method was used to analyze the relationship between MCUR1 and the prognosis of ovarian cancer patients. Immunohistochemistry was used to detect the expression of MCUR1 in ovarian cancer tissues. Ovarian cancer A2780 cells were transfected with MCUR1 interference fragments and overexpression plasmids（siMCUR1 group and MCUR1 group），and corresponding negative controls（siCtrl and EV group） were set respectively. qRT-PCR and Western blot assay were used to detect the effect of MCUR1 intervention. MTS method and clone formation experiment were used to detect cell proliferation. Immunohistochemical and TUNEL staining methods were used to detect proliferation and apoptosis after tumor-bearing subcutaneously in nude mice. The Western blot was used to detect proliferation and apoptosis-related molecules. Results The median overall survival of the MCUR1 high expression group was higher than that of the low expression group（53.7 months vs 41.3 months，P=0.003）. Compared with the siCtrl group，the cell proliferation ability of  the  si MCUR1 group increased（P<0.01），the growth of subcutaneous tumors in nude mice accelerated（P<0.01），Ki67 expression increased（P<0.01），and the apoptotic capacity decreased（P<0.05）； the expressions of p53，Caspase-3，and Bax protein decreased，whereas the expressions of Bcl2，Cyclin D1，and Cyclin E protein increased. Compared with the EV group，the cell proliferation ability of the MCUR1 group decreased（P<0.01），the growth of subcutaneous tumor-bearing tumors in nude mice slowed down（P<0.01），Ki67 expression decreased （P<0.01），and apoptotic capacity increased （P<0.05）； the expressions of p53，Caspase-3，and Bax proteins increased，whereas the expressions of Bcl2，Cyclin D1，and Cyclin E proteins increased. Conclusions MCUR1 regulates the proliferation and apoptosis of ovarian cancer cells by regulating the p53 pathway. MCUR1 may play a role as a tumor suppressor in ovarian cancer and become a target for diagnosis and treatment of ovarian cancer.

Key words: Ovarian cancer, MCUR1, Proliferation, Apoptosis, Prognosis