干扰素对肝癌细胞胸苷磷酸化酶表达和凋亡的双重影响

Effects of interferon-alpha on thymidine phosphorylase expression and apoptosis in human hepatocellular carcinoma SMMC-7721 cells

目的:进一步研究干扰素-α(IFN-α)对人肝癌细胞胸苷磷酸化酶(TP)表达及凋亡的双重影响.方法:体外分别用0、10、100、1000、5000、10000kU/LIFN-α处理人肝癌细胞SMMC-7721,RT-PCR检测细胞TPmRNA表达水平,免疫细胞化学方法检测细胞TP蛋白表达变化,流式细胞仪检测凋亡细胞百分比.结果:IFN-α上调SMMC-7721细胞TPmRNA表达水平,呈现剂量依赖性.与未处理组相比,浓度为5000、10000kU/L的IFN-α处理的细胞TPmRNA表达水平显著升高(P<0.05),而且细胞质内TP蛋白染色强度及阳性染色细胞数均较未处理组的细胞差别明显,但不同浓度的IFN-α对凋亡细胞百分比的影响不明显,对照组和浓度10000kU/LIFN-α组的凋亡细胞百分比分别为7.19%±2.76%和6.42%±3.66%,差别无统计学意义.结论:一定剂量的IFN-α既能上调肝癌细胞TP表达水平,又能抵消TP表达上调后抑制细胞凋亡的作用.

AIM： To investigate the effects of interferonalpha （IFN-α） on thymidine phosphorylase （TP） expression and apoptosis in human hepatocellular carcinoma SMMC-7721 cells. METHODS： The expression of TP mRNA was detected by reverse transcription-polymerase chain reaction （RT-PCR）. The expression of TP protein was evaluated by immunocytochemistry. The percentage of apoptotic cells was mea- sured by flow cytometry. RESULTS： IFN-α upregulated the expression of TP mRNA in a dose-dependent manner in SMMC-7721 cells. IFN-α at a dose of 5000 or 10 000 kU/L induced a 3-fold upregulation of TP mRNA compared to non-treated cells （P 〈 0.05）. Compared with non-treated cells, the intensity of TP staining and the number of TP-positive cells significantly increased in IFN-α treated cells （5000 or 10000 kU/L）. However, no significant difference was found in the percentage of apoptotic cells between IFN-α （10000 kU/L）- treated cells and non-treated cells （6.42% ± 3.66% vs 7.19% ± 2.76%, P 〉 0.05）. CONCLUSION： IFN-α at appropriate doses may upregulate the expression of TP mRNA and protein and antagonize TP-induced inhibition of apoptosis in human hepatocellular carcinoma cells.