Effects Of MicroRNA-375 On Biological Characteristics In Cervical Cancer Cell And Preliminary Study On Its Regulation On IGF-1R Expression

Objective:According to recent study, ectopic expression of micro RNA can lead to cervical cancer. Our previous studies showed that compared with normal cervical tissue, the level of mi R-375 expression is obviously less in cervical intraepithelial neoplasia(CIN) and cervical cancer. The present experiment aimed to detect the expression level of cervical caner cells and normal epithedlial cells. The result of the detection will validate the results of previous experimental. And the experiment will study the relationship between the expressions of mi R-375 and the cells proliferation, apoptosis and migration ability by interfering the expression of mi R-375 in cervical cancer cells. The experiment will further to determine the target genes of mi R-375, and clarify the role of mi R-375 in the possible molecular mechanisms under the cervical cancer.Methods:1) Real-time PCR technology was used to detect the expression level of mi R-375 in cervical cancer cell lines(Caski, C33A) and normal epithelial cell line(293T).(2) In cervical cancer cell lines(Caski), mi R-375 over expression and low expression were achieved by transfection with chemical synthetic mi R-375 mimic and mi R-375 inhibitor oligonucleotides with si RNA-Mate transfection reagents. Real-time PCR technology was used to detect the expression level of mi R-375.(3) The functional effect of mi R-375 on cell proliferation, migration and apoptosis was evaluated using Cell Counting Kit(CCK8),scratch wound test and apoptosis test,respectively.(4) Western blot technology was used to detect the expression level of IGF-1R protein.Results:(1) The relative expression of mi R-375 in 293 T, Caski and C33 A are 0.885±0.034,0.050±0.004, 0.080±0.003, respectively. Compared with normal epithelial cell, the expression of mi R-375 is significantly down-regulated in cervical cancer cell(P<0.05).(2) In transfection of mi R-375 mimic group, compared with negative control,the expression of mi R-375 showed about 7.76 fold up-regulation(P < 0.05), cell proliferation and migration were significant reduced(P < 0.05), cell apoptosis were significant promoted(P < 0.05), the expression of IGF-1R protein showed a 24.73%decrease(P < 0.05). In contrast, the transfection of mi R-375 inhibitor made the expression of mi R-375 showed a 14.39 % decrease(P < 0.05), cell proliferation and migration were significant promoted(P<0.05), cell apoptosis were significant reduced(P<0.05), the expression of IGF-1R protein showed a 2.29 fold up-regulation(P<0.05).While each of negative control showed no significant changes compaired with the blank control in each index(P>0.05).Conclusions:(1) mi R-375 is significant down-regulated in cervical cancer cell;(2) In Caski,the over expression of mi R-375 can inhibit cell proliferation and migration,increase apoptosis,and decreased the expression of IGF-1R protein;to reduce the expression of mi R-375 can promotes cell proliferation and migration, reduce apoptosis,and increas expression of IGF-1R protein. This suggests that mi R-375 plays an important role in the tumorigenesis and development of cervical cancer.IGF-1R might be a targeted gene of mi R-375 in cervical cancer. mi R-375 might regulate the biological behavior by targeting IGF-1R.