Expression of miR-496 in ovarian serous carcinoma and its targeting correlation with SIX1

Abstract:

Objective：To detect the expression of microRNA-496（miR-496） in ovarian serous carcinoma，so as to observe its expres－sion significance，and to analyze its correlation with homologous heteroprotein sine oculis homeobox homolog 1（SIX1）. Methods：A total of 75 patients with ovarian serous carcinoma were selected as the observation group，and another 75 patients with ovarian serous cystic adenoma were selected as the control group. Expression of miR-496 in two groups was detected by real-time fluorescence quantitative PCR. Expression of proliferating cell nuclear antigen（PCNA） and Bcl-2 associated X protein（BAX） in the observation group was detected by immunohistochemical method. Expression of SIX1 in the observation group was detected by Western blot. Ovarian serous cystic adenoma cell lines were selected；blank control group，micR-496 transfection group，and miR-496 and SIX1 co-transfection group were set up. Relationship between miR-496 and target gene SIX1 was verified by applying double luciferase gene experiment. Results：Expression of miR-496 in the observation group was significantly lower than that in the control group（1.52±0.36 vs. 2.03±0.25，t=7.56，P=0.001）. The expression of miR-496 was statistically significant in different groups of tumor maximum diameter（1.65±0.36 vs. 1.42±0.33，t=5.32，P=0.012），histological grade（1.64±0.35 vs. 1.43±0.40，t=5.11，P=0.010），vascular in－volvement（1.60±0.44 vs. 1.35±0.43，t=5.11，P=0.011），bilat－eral occurrence（1.61±0.36 vs. 1.40±0.32，t=5.11，P=0.010），lymph node metastasis（1.62±0.42 vs. 1.35±0.41，t=5.66，P=0.008） and different TNM stages（1.70±0.37 vs. 1.42±0.39，t=5.65，P=0.009）. Expression of miR-496 was related with survival time（ χ2=4.13，P=0.010）；it had negative correlation with PCNA（r=-0.54，P=0.019） and SIX1（r=-0.58，P=0.013）；it had positive correlation with BAX（r=0.52，P=0.011）. Double luciferase gene experiment results showed that miR-496 was able to significantly reduce the luciferase activity in pGL3-SIX1-WT transfected cell lines. Conclusion：Expression of miR-496 in ovarian serous carcinoma is decreased，which is the molecular factor for accelerating tumors’ formation and development. Detection of miR-496 has a certain significance for judging the prognosis. MiR-496 may regu－late cell proliferation and apoptosis by negatively regulating the expression of SIX1.