摘要目的 探讨甲胎蛋白(AFP)对耐药基因MDR1表达和肝癌细胞化疗敏感性的影响.方法 建立稳定表达AFP的肝癌细胞系SMMC-7721/AFP,分别通过Real-time PCR和蛋白印迹检测转染前后AFP和MDR1的表达.MTT法测定SMMC-7721/AFP和SMMC-7721/EGFP细胞对阿霉素的化疗敏感性.siRNA沉默SMMC-7721/AFP细胞中MDR1的表达,观察细胞对阿霉素化疗敏感性的变化.采用免疫组织化学染色法检测60例肝癌组织中MDR1编码蛋白PgP的表达,分析Pgp表达与血清AFP水平的相关性.结果 在SMMC-7721/AFP细胞能检测到AFP mRNA和蛋白表达,而对照细胞则未检测到AFP表达,表明AFP稳转细胞系构建成功.SMMC-7721/AFP细胞中MDRl mRNA和蛋白水平明显高于对照细胞,SMMC-7721/EGFP和SMMC-7721/AFP细胞MDRl mRNA水平为对照组的(52.7±1.5)倍(P＜0.05).SMMC-7721/AFP细胞对阿霉素的耐药性增加了(12.8±1.1)倍(P＜0.05).siRNA沉默SMMC-7721/AFP细胞中MDR1的表达后细胞对阿霉素的化疗敏感性明显增强.肝癌组织中Pgp的表达和血清AFP水平呈正相关.结论 AFP可通过上调MDR1的表达引起肝癌细胞对阿霉素耐药.

abstractsObjective To explore the influence of alpha-fetoprotein (AFP) on the expression of drug-resistance gene MDR1 and chemotherapeutic sensitivity in hepatocellular carcinoma (HCC) cells.Methods A HCC cell line SMMC-7721/AFP, which was stably transfected with AFP gene, was established.mRNA and protein expressions of AFP and MDR1 were detected by real-time PCR and Western Blot,respectively.The sensitivity of SMMC-7721/AFP and SMMC-7721/EGFP cells with or without MDR1 silencing by siRNA to doxorubicin was tested by MTT assay.Immunohistochemistry was used to detect the expression of MDR1 genes-coded protein Pgp in 60 cases of HCC tissues, and the relationship between Pgp expression and serum AFP levels was analyzed.Results AFP mRNA and protein could be detected in SMMC-7721/AFP cells, but not in control cells, indicating that the AFP stably transfected cell line was successfully established.MDR1 mRNA and protein levels were higher in SMMC-7721/AFP cells than those in SMMC-7721/EGFP cells.MDR1 mRNA level in SMMC-7721/AFP cells was (52.7 ± 1.5) times as high as that in SMMC-7721/EGFP cells (P ＜ 0.05).The resistance to doxorubicin was increased by (12.8 ± 1.1) times after AFP transfection (P ＜ 0.05).The chemosensitivity to doxorubicin was increased after the expression of MDR1 was knocked down by siRNA.The expression of Pgp in HCC tissues was positively correlated with the serum AFP levels.Conclusion AFP could induce drug-resistance to doxorubicin in HCC cells by increasing the expression of MDR1.