Effect of miR-33a-3p on Chemoresistance of Colorectal Cancer by Regulating EphA2 / 华中科技大学学报(医学版)

ABSTRACT

@#Objective Toinvestigatetheregulatoryeffect of microRNA-33a-3p(miR-33a-3p)on chemoresistances of colorectal cancer(CRC). Methods Theexpression of miR-33a-3pin CRC parentalcells(HCT8)and drug-resistantcelllines(HCT8/5-Fu and HCT8/DDP) was detected by quantitative real-time PCR. The miR-33a-3p mimics and negative control mimics were constructed andtransfectedinto CRCdrug-resistantcells. Cell proliferation,apoptosis,cellcycledistributionandchemosensitivity weretested. Thetarget genes of miR-33a-3p were predicted via bioinformatics methods,andtheeffect of overexpressed miR- 33a-3p onthe downstreamtarget gene EphA2 was detected by quantitative real-time PCR and Western blot. Results The expression of miR-33a-3pin HCT8/5-Fu and HCT8/DDP cells was significantlylowerthanthat ofthe parentalcells(P <0.01) .Compared with the negative control group,overexpression of miR-33a-3p could suppress HCT8/5-Fu and HCT8/DDP cells proliferation and promotecell apoptosis,and block cells cyclein G2/M phase as well as enhancecell chemosensitivity(P <0.05) .Bioinformatics predictionresults showedthat EphA2 might bea downstreamtarget gene of miR-33a-3p,andits expression was significantlyreducedin HCT8/5-Fu and HCT8/DDP cells transfected with miR-33a-3p mimics. Conclusion The miR-33a-3p mayreversethechemoresistance of CRC byregulatingthe expressionlevel of downstreamtarget gene EphA2.