MiR-143 Reduced DNMT3B Expression Increase The Susceptibility Of Adriamycin To Hepatocellular Carcinoma

Objective: Liver cancer is one of the most common malignant tumor in the world, has become a global health problem. Chemotherapy is a major treatment, however chemotherapy drug resistance to hepatocellular carcinoma(HCC) led to the failure of chemotherapy, but the resistance mechanisms of tumors is unkonwn. Gene regulation research mediated by micro RNAs has made great progress in recent years, but also micro RNAs is related to the resistance mechanisms of tumors. We constructed the hepatocellular carcinoma SMMC-7721 cell line model resisted to adriamycin(doxorubicin), and analysized the expression of mi R-143, DNMT3 B and MDR1 between liver cancer cell adriamycin resistant cell lines and their parent cell lines, further explored the role of mi R-143 in the resistance mechanisms of hepatocellular carcinoma to adriamycin, we hope that our findings will help to increase the survival rates of clinical adriamycin-resistant patients.Methods: The drug-resistant cell line SMMC-7721/ADM was constructed by added adriamycin with low dose and continuous dose increase step by step. IC50 value of parent cells and SMMC-7721/ADM and resistance index(RI) were determined by MTT method. Cell growth curve and cell number of parent cells and SMMC-7721/ADM were detected by cell counting method. Cell morphological differences between parent cells and SMMC-7721/ADM were investigated in microscopy. The expression of DNMT3 B, MDR1, Bcl-2, Bax m RNA and expression of mi R-143 were detected through fluorescence quantitative PCR between parent cells and SMMC-7721/ADM. DNMT3 B protein expression were determined by Western Blot between parent cells and SMMC-7721/ADM. In addition, SMMC-7721/ADM were transfected with mi R-143 mimics with transiently transfection experiments. IC50 value and resistance index(RI) of SMMC-7721/ADM before and after transfected were determined by MTT method; Cell migration changes of SMMC-7721/ADM were detected with transwell method; cell apoptosis changes were determined through Flow cytometry; DNMT3 B and MDR1 m RNA expression quantity changes were detected by Fluorescence quantitative PCR technique; DNMT3 B protein expression changes were determined through Western blot method.Result: We successfully constructed hepatocellular carcinoma resistant cell line SMMC-7721 with 3.0 μg/m L adriamycin(SMMC-7721/ADM). IC50 value of SMMC-7721/ADM was increased(p<0.05); the growth proliferation and mi R-143 expression in resistant cells was decreased(p<0.05); the m RNA expression of DNMT3 B, MDR1, Bax, Bcl-2 was increased(p<0.05); the expression of DNMT3 B protein of SMMC-7721/ADM was increased. In SMMC-7721/ADM transfected with mi R-143 mimics, the IC50 value was decreased(p<0.05); the invasive ability reduced(p<0.05); the apoptosis increased(p<0.05); DMT3 B and MDR1 m RNA expression decreased(p<0.05); DNMT3 B protein expression also decreased(p<0.05); respectively.Conclusion: We successfully constructed hepatocellular carcinoma resistant cell line SMMC-7721 with low dose and continuous dose increase step by step. DNMT3 B protein expression was decreased in SMMC-7721/ADM transfected with mi R-143 mimics. mi R-143 reduced DNMT3 B expression increase the susceptibility of adriamycin to hepatocellular carcinoma.