To explore the expression level of membrane-associated protein Numb in epithelial ovarian cancer(EOC) and its relationship with drug resistance P-glycoprotein(P-gp) and multidrug resistance-associated protein(MRP)-1.

A total of 136 patients who had ovarian tumors and 22 patients who had hysterectomy and bilateral salpingooophorectomy only for the lesion in uterus from January 2012 to June 2014 in department of Gynecology and Obstetrics, West China Second University Hospital, Sichuan University were chosen as study subjects.According to the histopathologic examination results of ovaries tissues, they were divided into EOC group(n=92), borderline ovarian tumor(BOT) group(n=23), ovarian benign tumor group(n=21) and normal ovary group(n=22). Expression levels of Numb protein, P-gp and MRP-1 in ovarian tissues were detected by immunohistochemical SP method, the positive expression rates differences of Numb protein among 4 groups and in patients of different clinical characteristics in EOC group were analyzed statistically. The positive expression rates differences of these 3 kinds of protein and their correlation in EOC group, and the relationship with chemotherapy sensitive and chemotherapy resistance were analyzed statistically.This study was approved by the ethic committee of West China Second University Hospital, Sichuan University, and consent forms were signed by all the patients.There were no significant differences among 4 groups in general clinical data, such as age, body height and body mass, etc.(P>0.05).

①The positive expression rate of Numb protein in EOC group was higher than that in benign tumor or normal ovary group, also Numb protein positive expression rate in BOT group was higher than that in normal ovary group, and the differences were statistically significant(P<0.05). However, there were no significant differences of Numb protein positive expression rates neither between EOC group and BOT group, nor between BOT group and ovarian benign tumor group, nor between ovarian benign tumor group and normal ovary group(P>0.05). ②Comparison of Numb protein positive expression rate in ovarian tissue in EOC group: the positive expression rate in FIGO stageⅠ-Ⅱ was lower than that in stage Ⅲ-Ⅳ, also the same in no lymph nodes metastasis compared with lymph nodes invasion, and the differences were statistically significant(P<0.05). While there were no significant differences among different age, clinical pathology types, pathological grades and residual tumor size(P>0.05). ③There was no significant difference between Numb protein and P-gp positive expression rate in EOC group(P>0.05), also there was no correlation between them(r=0.117, P=0.109). However, the positive expression rate of Numb protein was lower than that of MRP-1, and the difference was significant(P<0.05), also they were positively correlated(r=0.179, P=0.013). ④A total of 78 EOC patients were followed up successfully for chemoresistance, among them, 65 patients were chemotherapy sensitive and 13 patients were chemotherapy resistant.There were no significant differences between chemotherapy sensitive and resistant patients in positive expression rates of Numb protein, P-gp and MRP-1(P>0.05). Also, there was no significant difference of positive expression rate between any two of these 3 kinds of protein in chemotherapy sensitive or resistant patients(P>0.05).

Numb gene might be an oncogene in the development of ovarian neoplasms.Numb protein may be related with proliferation, invasion and metastasis of ovarian neoplasms tumor cell.The expression of Numb protein is correlated with the expression of MRP-1, but a further large sample research is needed to be done to certify whether Numb protein can act as a predictive parameter of chemotherapy sensation.