Abstract: 【Abstract】Objective To investigate the expression of microRNA-545（miR-545）in cervical cancer tissues and cell lines as well as its effect on the biological behavior of cervical cancer Hela cells. Methods The real time quantitative PCR（qPCR）was used to detect the level of miR-545 in 52 cases of cervical cancer，30 cases of cervical intraepithelial neoplasia（CIN）and 25 cases of normal cervical tissues. The relationship between miR-545 expression and clinical pathological parameters of cervical cancer was analyzed. The expression of miR545 in cervical cancer cell lines（Siha，Hela，CaSki，C33a）and normal epithelial cells was also detected. The miR545 expression vector pcDNA6.2／GW／EmGFP-miR-545 was transfected into cervical cancer cells with the lowest level of miR-545(overexpression group). Meanwhile, the pcDNA6.2/GM/EmGFP-miR empty control group and black control group were set up. The proliferation level（methylthiazolyl tetrazolium），apoptosis（flow cytometry with Annexin V／PI double staining） and cell cycle（flow cytometry with PI staining）of Hela cells were analyzed.
Results The relative level of miR-545 was 0.245±0.051 in cervical cancer tissues，lower than 0.761±0.073 in CIN tissues and 1.027±0.024 in normal cervical tissue with statistical significance（P＜0.05）. The miR-545 level in cervical cancer tissues was associated with clinical stage，differentiation degree and lymph node metastasis（P＜0.05）. Compared with normal cervical cells，the miR-545 levels of cervical cancer cells were decreased，which were followed by CaSki，C33a，Siha and Hela cells. Compared with empty control group and blank control group，the cell proliferation inhibition rate，apoptosis rate and the percentage of G0／G1 phase cells were increased but the proportion of S and G2／M phase cells were decreased in over-expression group with statistical difference（P＜0.05）. Conclusion miR-545 is low expressed in cervical cancer tissues and cells，and up-regulation of miR-545 exhibited the effect of inhibiting proliferation,inducing apoptosis and arresting cell cycle，which has certain value in the prevention and treatment of cervical cancer.