Abstract: Objective To investigate the targeting relationship between miR-99a and ribonucleotide reductase subunit M2 (RRM2)and to analyze their effects on proliferation, invasion and migration of cervical cancer (CC)-oringinated HeLa cell line. Methods HeLa cells were divided into control group, negative control group (inhibitor-NC), inhibition of miR-99a expression group (miR-99a-inhibitor) and co-transfection group (RRM2-siRNA+miR-99a-inhibitor). MTT assay and plate colony experiment were used to detect the proliferation ability of HeLa cells. Scratch test and Transwell test were used to detect cell migration and invasion ability respectively. Western blot was used to detect protein expression of RRM2, proliferating cell nuclear antigen (PCNA), E-cadherin, N-cadherin and vimentin.Immunofluorescence method was used to detect the localization and expression of E-cadherin, N-cadherin and vimentin. Bioinformatics and dual-luciferase reporter gene experiments verified the targeting relationship between miR-99a and RRM2. RT-qPCR were used to detect the expression levels of miR-99a and RRM2 mRNA in HeLa cells in each group. Results Down-regulating the expression of miR-99a increased proliferation of HeLa cells (100.00 vs. 128.86±4.25, P＜0.05). Up-regulated colony formation improved scratch healing rate, and increased the number of invasive cells and the expression of RRM2, PCNA, N-cadherin and vimentin protein, decreased E-cadherin protein expression (P＜0.05). Inhibition of RRM2 expression reversed the effect of down-regulation of miR-99a on the biological behavior of HeLa cells(P＜0.05). Dual-luciferase reporter gene experiment and RT-qPCR confirmed that miR-99a had a targeting relationship with RRM2 (P＜0.05). Conclusions Inhibition of miR-99a may target at up-regulating the expression of RRM2 to promote the development of HeLa cells, which is expected to become a new potential therapeutic target for CC.

Key words: miR-99a, ribonucleotide reductase subunit M2, cervical cancer cell, proliferation, migration