The Research Of5-lfuorouracil Resistance Mechanisms In Human Hepatoma Cell Lines SMMC-7721

Objective:Primary liver cancer is one of the common malignant tumors in digestivesystem, seriously threat to the health of people. Because of difficulties in earlydiagnosis, liver cancer mostly was progressed when diagnosed, and patients aftersurgery also relapsed easily.Therefore, systemic chemotherapy become the maintreatment for advanced liver cancer.5-Fluorouracil (5-FU) is the main chemotherapydrug of liver cancer in the world. However, the clinical efficacy is still not optimistic.The main reason of the failure of treatment is the acquired resistance.Therefore,it iswell worth studying the resistance mechanisms of5-FU in human hepatoma cell lineSMMC-7721.In this study,we developed5-FU resistant strains SMMC-7721/5-FUcell line. Detected differently expressed proteins between the parental sell lineSMMC-7721and drug resistant cell line SMMC-7721/5-FU by Proteomics,findingsome differentially expressed proteins.Selected some of the proteins which mayberelated to the resistance of5-FU in SMMC-7721.And further investigated themechanisms of interest proteins in the5-FU acquired resistance.Methods: We used2-DE and MALDI-TOF-MS to analysis the protein expressionprofile of SMMC-7721and SMMC-7721/5-FU,detected the differently expressedproteins(Completed in Nanjing Medical University Laboratory). The results werevalidated by Semi-RT-PCR and Western blot in gene and protein expressionlevels.Besides, to study the influence of5-FU gene biological activity,we used smallinterfering RNA to knocked out interesting genes of SMMC-7721/5-FU.Results: We have successfully identified a group of proteins,which differentlyexpressed between the SMMC-7721and SMMC-7721/5-FU,including79up-regulated proteins (Such as HSP27, PRDX6, PHB, PSMB7, MYL6, HNRNPL),23down-regulated proteins (Such as Maspin, HN1, p16, MTAP).The results werevalidated by Semi-RT-PCR and Western blot.Further more, we found thatdown-regulation of PRDX6and PSMB7enhanced SMMC-7721/5-FU cells to5-FU sensitivity.Conclusion: A group of abnormal expressed genes maybe related to the resistancemechanisms of5-FU in human hepatoma cell line SMMC-7721.Down-regulationPRDX6, PSMB7expression can partially overcome5-FU resistance in liver cancer.