下咽癌相关血浆肿瘤标志物的蛋白质组学筛选

Screening of plasma tumor biomarkers for hypopharyngeal carcinoma by proteomics method

目的分析下咽癌患者与健康人血浆中差异表达的蛋白质组,筛选潜在的与下咽癌诊断密切相关的血浆肿瘤标志物。方法取下咽癌患者与健康人空腹血浆标本各6例分别等量混合成2组样本,去除血浆高丰度蛋白后,利用双向电泳(2-DE)进行分离,经软件分析后找出表达量变化2倍以上的差异蛋白点,接着利用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF/TOF)进行差异蛋白质鉴定,然后利用Western blotting对α2-HS-糖蛋白的表达量进行验证。结果下咽癌患者与健康人血浆相比较,筛选出表达量差异2倍以上的差异蛋白点共11个,其中表达上调的有5个,表达下调的有6个,进行质谱分析后,表达上调的蛋白有α2-HS-糖蛋白、结合珠蛋白;表达下调的蛋白有免疫球蛋白κ链C结构域、载脂蛋白A1。Western blotting结果表明,α-2-HS-糖蛋白的表达上调,与双向电泳结果一致。结论下咽癌患者与健康人血浆的蛋白质表达谱表现出一定差异,这些差异蛋白有可能成为下咽癌患者早期诊断的特异性血浆肿瘤标志物。

Objective To screen tumor biomarkers in the plasma close related with hypopharyngeal carcinoma.Methods Pooled plasm from 6 patients with hypopharyngeal carcinoma and 6 healthy individuals were collected.After removal of highabundance plasm proteins,two-dimensional gel electrophoresis(2-DE) was performed to isolate the total proteins,and the protein spots with more than 2-fold differential expressions were detected by 2D analysis software followed by identification by MALDI-TOF/TOF mass spectrometer.Western blotting was performed to validate the expression level of α2-HSglycoprotein.Results A total of 11 differentially expressed protein spots were selected,including 5 upregulated proteins and 6 downregulated proteins.MALDI-TOF/TOF identified the upregulated proteins in hypopharyngeal carcinoma patients as alpha-2-HS-glycoprotein and haptoglobin and downregulated ones as Ig kappa chain C region and apolipoprotein A-I.Western blotting demonstrated that α-2-HS-glycoprotein expression level was consistent with that detected by 2-DE.Conclusion Patients with hypopharyngeal carcinoma show different plasma protein profiles from healthy individuals.These differentially expressed proteins may serve as potential specific tumor biomarkers for hypopharyngeal carcinoma.