Effect of the DNMT3B expression on regulated by miR-143 the sensitivity of the hepatocellular carcinoma resistance to adriamycin

Objective: To establish hepatocellular carcinoma cell line SMMC-7721/ADM resistance to adriamycin,and explore the mechanism of microRNA(miR)-143 in regulating the cell line resistance to adriamycin.Methods: The cell line SMMC-7721/ADM resistance to adriamycin was constructed using the gradual increasing the concentration of adriamycin,and the IC₅₀ value of which was evaluated.The mRNA expression levels of miR-143, DNA methyltransferase 3B(DNMT3B) and multidrug resistance gene 1(MDR1),Bax and Bcl-2 genes were evaluated using real-time fluorescent quantitative PCR,and the protein level of DNMT3B was determined by Western blotting.After the miR-143 mimics upregulating the miR-143 expression in SMMC-7721/ADM cell line,the IC₅₀ value,invasion ability,cell apoptosis,and levels of DNMT3B,MDR1 were detected.The miR-143 mimics was transiently transfected into the drug resistance cell line using liposome-2000,and the indexes changes were observed.Results: The cell line SMMC-7721/ADM resistance to adriamycin was successfully established,the IC₅₀ value raised 78.97 times(P<0.01).The expression level of miR-143 decreased,and the expression levels of DNMT3B,MDR1,Bax and Bcl-2 increased,and the differences of which were statistically significant(P<0.05 to P<0.01).After the miR-143 mimics transfecting into the drug resistance cell line,the IC₅₀ value reduced 57%,the invasion ability declined,the cell apoptosis increased,the levels of DNMT3B and MDR1 mRNA decreased,and the differences of which were statistically significant(P<0.01).Conclusions: The increasing sensitivity of hepatocellular carcinoma to adriamycin may be caused by the miR-143 reducing DNMT3B expression.