肿瘤坏死因子alpha上调人结肠癌细胞株突变型p53蛋白的表达

Effect of tumor necrosis factor alpha on mutant p53 protein expression in colorectal cancer cell lines

目的:研究TNF-alpha对人结肠癌细胞株HT-29及HCT116 p53表达的影响。方法:给予人结肠癌细胞株HT-29(表达突变型p53蛋白)及HCT116(表达野生型p53蛋白)不同浓度的TNF-alpha刺激后,应用细胞免疫荧光及实时荧光定量PCR检测突变型p53蛋白表达及p53 mRNA水平的改变。结果:免疫荧光显示TNF-alpha刺激后能显著提高HT-29细胞核突变型p53蛋白的表达(P<0.05),而对表达野生型p53的HCT116的p53水平无明显改变。实时荧光定量PCR结果表明TNF-alpha刺激对HT-29及HCT-116的p53 mRNA水平无明显改变。结论:TNF-alpha能显著上调HT-29突变型p53蛋白的表达,但是该上调作用并不是发生于转录水平。TNF-alpha刺激对表达野生型p53的HCT116细胞株p53水平无明显改变。

Objectives： To evaluate the effect of TNF-alpha on mutant p53 expression in colorectal cancer cell lines.Methods： The cell lines HT-29（which expresses mutant p53） and HCT116（which expresses wild-type p53） were stimulated with TNF-alpha at different concentrations.Immunofluorescence and real-time quantitative RT-PCR were performed to detect the alterations of p53 protein and transcripts.Results： Immunofluorescence indicated that TNF-alpha can markedly induce nuclear p53 protein expression in HT-29 cells;in contrast,the effect of TNF-alpha on p53 expression in HCT116 cells was minimal.Real-time quantitative RT-PCR showed no substantial change of p53 mRNA in HT-29 or HCT116 cells after stimulation with TNF-alpha.Conclusions： TNF-alpha can dramatically induce nuclear mutant p53 protein expression in HT-29 cell line which expresses mutant p53,and this induction wasn＇t ascribed to the transcription upregulation.But this p53-induction effect of TNF-alpha was minimal in HCT116 cell line which expresses wild-type p53.Our findings suggest that TNF-alpha may be a risk factor in the carcinogenesis of IBD patients carrying a p53 mutation.