Lin28与肝癌细胞紫杉醇耐药关系的研究

摘要

Objective Lin28 is a reprogramming factor and conserved RNA-binding protein. Lin28 has two homologs, Lin28A and Lin28B. Lin28B is the only homolog of Lin28A in humans, sharing structure and certain function. In this study, we examined the expression of Lin28 in three hepatocellular carcinoma celllines to investigate and evaluate the relationship between Lin28 and the paclitaxel-resistant of hepatocellular carcinoma cells. [Methods] cellviability assay of Hep3B, HepG2 and SMMC-7721 cells was measured using the MTT viability test, and calculated the half maximal inhibitory concentration (IC50) of taxol. The expression of Lin28A and Lin28B in Hep3B, HepG2 and SMMC-7721 cells at RNA and protein levels were analyzed by RT-PCR and Western Blot.[Results] The IC50 values of three celllines to paclitaxel treatment were 0.194μM for Hep3B cells, 19.54μM for HepG2 cells and 0.444μM for SMMC-7721 cells. The mRNA expression levels of Lin28A in HepG2, SMMC-7721 cells were 5.06 times, 3.10 times higher than in Hep3B cells; The Lin28B mRNA expression levels in HepG2, SMMC-7721 cells were 7.16 times, 3.16 times higher than in Hep3B cells. And similar results were obtained when Lin28A and Lin28B protein levels in Hep3B, HepG2 and SMMC-7721 cells were analyzed by Western Blot. [Con-clusions] Our study showed that Lin28 expression was closely associated with the paclitaxel-resistant of hepatocellular carcinoma cells, indicating that Lin28 expression might be one underlying mechanism of paclitaxel resistance in hepatocellular carcinoma cells, and Lin28 could be a potential target for over-coming paclitaxel resistance in liver cancers.%[目的]Lin28是一种重编程因子和保守的RNA结合蛋白，存在Lin28A和Lin28B两种同源基因，两者结构和功能类似。本研究旨在探讨Lin28与肝癌细胞对紫杉醇耐药的关系。[方法]MTT法检测紫杉醇对HepG2、Hep3B、SMMC-7721肝癌细胞的IC50；用荧光定量PCR法（简称RT-PCR）在RNA水平检测Lin28A和Lin28B在Hep3B、HepG2、SMMC-7721中的表达，蛋白质印迹法分析Lin28A和Lin28B蛋白在Hep3B、HepG2、SMMC-7721细胞中的表达情况。[结果]Hep3B、HepG2、SMMC-7721细胞株对紫杉醇的IC50分别为：Hep3B为0.194μM、HepG2为19.54μM、SMMC-7721为0.444μM。HepG2、SMMC-7721细胞株中的Lin28A基因表达量分别是Hep3B的5.06、3.10倍；HepG2、SMMC-7721细胞株中的Lin28B基因表达量分别是Hep3B的7.16、3.16倍。Hep3B、HepG2、SMMC-7721细胞株中Lin28A和Lin28B蛋白的表达量与从荧光定量数据显示的趋势一致。[结论]Lin28与肝癌细胞对紫杉醇耐药密切相关，肝癌细胞中Lin28表达与肝癌细胞对紫杉醇的耐药性成正比，暗示Lin28表达可能是肝癌细胞紫杉醇耐药的潜在机制并有望成为逆转肝癌紫杉醇耐药的靶点。