The Expression Of Hsa-mir-181a-5p In The Ovarian Cancer Tissues And Cells And Its Biological Functional Investigation

Chapter Ⅰ. Study of the expression of hsa-miR-181a-5p in the ovarian cancer tissues and its cor relationships with clinical staging and pathologic gradingObjective:To investigate the expression of hsa-miR-181a-5p in the ovarian cancer tissues and its clinical significance.Methods:RT-qPCR was utilized to measure the expression level of hsa-miR-181a-5p in the epithelial malignant tumor, benign tumor and normal epithelial tissues of ovary. The relationship between the expression level of hsa-miR-181a-5p and the clinical stage and histological grade of epithelial ovarian cancer was analysed.Resluts:The expression level of hsa-miR-181a-5p in the EOC group was significantly lower than that in the normal control group and benign tumor group (9.67±4.78vs18.76±5.29, P<0.01;9.67±4.78vs15.45±4.46, P<0.05), and the difference between the latter two groups was not significant(P>0.05). Among the16EOC tissue samples, the expression level of hsa-miR-181a-5p in the serous cystadenocarcinoma group and mucinous cystadenocarcinoma group and endometrioid carcinoma group were8.21±3.56,9.78±4.85and9.88±1.24respectively, and the differences among the three groups were not significant(P>0.05); the expression level of hsa-miR-181a-5p in the Ⅲ-Ⅳ stage group was lower than that in the Ⅰ-Ⅱ stage group, but the difference was not significant (8.77±4.56vs10.89±3.16, P>0.05); the expression level of hsa-miR-181a-5p in the G3(lower differentiation) group was significantly lower than that in the G1(higher differentiation) group (5.54±2.35vs12.78±2.15, P<0.05), and the differences between G3and G2(middle differentiation) group and between G2and G1group were not significant(P>0.05).Conclusions:1.Hsa-miR-181a-5p was down-regulated in the epithelial ovarian cancer tissues, which indicated that hsa-miR-181a-5p may play a role as tumor suppressor.2.The expression level of hsa-miR-181a-5p in the epithelial ovarian cancer cellss was not associated with the pathological pattern and clinical staging, but likely to be associated with histological grading. Chapter Ⅱ. Study of the effect of hsa-miR-181a-5p on the biological functions of ovarian cancer OVCAR3cell lineObjective:To investigate the effect of hsa-miR-181a-5p on the biological functions of ovarian cancer OVCAR3cell line.Methods:The ovarian cancer OVCAR3cells were categorized into3groups, namely experimental group, negative control group and blank control group. Each group had3parallel samples. Hsa-miR-181a-5p agomir and scramble RNA were respectively transfected into the experimental group and negative control group. RT-qPCR, MTT, single PI staining, AnnexinV/PI double staining, Transwell methods and Western blotting were respectively utilized to measure the expression level of hsa-miR-181a-5p, proliferation, cell cycle, apoptosis, invasion conditions and the expression of Bcl-2protein in each group.Resluts:When the OVCAR3cell line had been transfected by hsa-miR-181a-5p agomir for24,72,120hours, the hsa-miR-181a-5p expression level in the experiment group was25.56±3.48,21.23±2.53,17.46±2.49respectively, and they were all significantly higher than that in the negative control group(14.27±3.11,14.56±2.89,13.82±2.53respectively) and blank control group(13.25±2.78,12.31±2.35,11.62±2.68respectively), P<0.05or0.01. When transfected after48and72hours, the OD value of cell proliferation in the experiment group were both significantly lower than that in the negative control group(0.410±0.031vs0.600±0.015, P<0.05;0.439±0.031vs0.724±0.024, P<0.01). When transfected after72hours, the cell percent of G0/G1in the experiment group was58.1±2.46%, and significantly higher than37.0±1.60%in the negative control group and36.2±1.75%in blank control group, P<0.01; the mean apoptosis rate in the experiment group was23.33±2.08%, and significantly higher than11.00±2.64%in the negative control group and8.33±2.51%in blank control group, P<0.05; the mean invasion cell number in the experiment group was21.33±3.05, and significantly lower than38.33±2.08in the negative control group and41.0±2.64in the blank control group, P<0.01; the mean expression level of Bcl-2protein in the experiment group was0.282±0.031and significantly lower than0.642±0.106in the negative control group and0.635±0.078in the blank control group, P<0.01.Conclusions:1.Hsa-miR-181a-5p expression level was significantly higher in the experimental group than that in the negative control and normal control groups, which indicated that the transfection of hsa-miR-181a-5p agomir was successful and valid.2.Hsa-miR-181a-5p can suppress cell proliferation by impeding cell cycle progression at G0/G1check point, at the same time, it can facilitate apoptosis and reduce the capacity of invasion and metastasis.3.Hsa-miR-181a-5p agomir had the potential to serve as a kind of genic medicine of EOC in the future.