Abstract: Objective To investigate the relationship between the expression of human ubiquitin-conjugating enzyme E2C(UBE2C),non-metastatic cell gene 2(NME2) and the clinicopathological features of breast cancer and its prognostic value.Methods The expression of UBE2C and NME2 in 1085 cases of breast cancer tissues and 291 cases of normal tissues were analyzed by GEPIA online website.The Kaplan-Merier Plotter online website was used to analyze the expression of UBE2C and NME2 and the survival of 1070 patients with breast cancer.Furthermore,one hundred and twenty-seven breast cancer patients admitted to our hospital from January 2018 to December 2019 were selected as the study subjects,and 51 healthy women who underwent physical examination in our hospital during the same period were selected as the normal control group.The levels of UBE2C and NME2 were detected,and the relationship between the levels of UBE2C and NME2 in patients with breast cancer and clinicopathological characteristics was analyzed.Multivariate Cox regression model was used to analyze the prognostic risk factors of breast cancer.The receiver operating characteristic curve was used to evaluate the efficacy of the model in predicting the poor prognosis of breast cancer.Results  GEPIA online website data showed that the expression levels of UBE2C and NME2 protein in breast cancer tissues were higher than those in the normal group,with a statistically significant difference(P＜0.05).Survival curve analysis showed that with the increase of UBE2C and NME2 expression levels,the survival rate of patients decreased(P=0.029,0.013,respectively).The positive expression rates of UBE2C and NME2 in breast cancer tissues were significantly different among patients with lymph node metastasis,clinical stage and pathological grade(χ2=7.826,4.116,5.460,P=0.005，0.042，0.019;χ2=4.400,6.211,11.63;P=0.036，0.013，0.001).Cox regression analysis showed that lymph node metastasis,clinical stage Ⅲ~Ⅳ,pathological grade G3 and UBE2C positive expression,NME2 positive expression were the risk factors for poor prognosis of breast cancer patients(P=0.031,0.018,0.016,0.019,0.001).Area under curve was 0.835,and the sensitivity was 0.740 3,the specificity was 0.941 2.The AUC of the validation group is 0.826,the sensitivity was 0.8800,and the specificity was 0.840 0.Conclusion The levels of UBE2C and NME2 in breast cancer patients are increased,and their expression is related to lymph node metastasis,clinical stage,pathological grade and poor prognosis of breast cancer.The constructed prediction model of breast cancer has an important clinical value for predicting the poor prognosis of breast cancer patients.

Key words: breast cancer, ubiquitin conjugating enzyme E2C, non-metastatic cell gene 2, prognostic value, biomarkers