应用蛋白质组学方法初步筛选与鼻咽癌放射敏感相关的蛋白

目的:通过筛选放射敏感性不同的鼻咽癌细胞中差异表达蛋白,以发现与鼻咽癌放射敏感相关的蛋白。方法:放射处理并结合流式细胞术检测及比较5-8F和6-10B细胞的放射敏感性。提取细胞总蛋白,进行双向凝胶电泳、MALDI-TOF肽质指纹图分析、质谱数据的蛋白质库搜寻鉴定。应用Western Blot检测细胞中蛋白质表达。应用免疫组织化学方法检测鼻咽癌组织中相关蛋白的表达。结果:双向凝胶电泳后对胶上的部分分辨较好的差异蛋白质点进行肽质谱指纹图分析和鉴定,在两种细胞中差异表达最为显著的蛋白质有9个。Western Blot证实CK19和P73在5-8F和6-10B表达与蛋白质组结果一致。P73在鼻咽癌放射敏感组和不敏感组中的表达阳性率分别为90%、57.5%,存在显著性差异。结论:放射敏感性不同的鼻咽癌细胞中存在一些差异表达蛋白,这些蛋白可能与鼻咽癌放射敏感性有关,其中P73可能成为放射敏感性预测的侯选标志物。

Screening of Radiosensitivity Associated Proteins in Nasopharyngeal Carcinoma by Proteomic Technique

Objective:To discover the proteins related to nasopharyngeal carcinoma radiosensitivity by screening differentially expressed proteins in nasopharyngeal carcinoma cell lines with different radiosensitivities.Methods:Radiosensitivity of 5-8F and 6-10B was assayed and compared by flow cytometry after irradiation.The total proteins from 5-8F and 6-10B were separated by immobilized pH gradient(IPG)IEF-SDS two-dimensional gel electrophoresis technology.Some differentially expressed proteins were cut from the gel and digested into several peptides,thereby preparing samples for MALDI-TOF MS and the Q-TOF mass spectrometric analysis.Then identification of these proteins could be made through searching in protein sequence database.The protein expressions were assayed by Western Blot and immunohistochemistry method.Results:Part of protein spots was analyzed by MS and bioinformatics and 9 cells were found with the most differentially expressed proteins in 5-8F and 6-10B cells.Western blot confirmed that the P73 and CK19 expressions were identical with the results from proteomic method.The positive rate of P73 in radiosensitivity group and non-radiosensitivity group was 90% and 57.5%respectively,with significant difference.Conclusion:Differentially expressed proteins ,which may be associated to radiosensitivity,exist in nasopharyngeal carcinoma cell lines with different radiosensitivities,and P73 may be the candidate biomarker.