蛋白质组学检测结直肠腺瘤及早期恶变患者血清的差异蛋白质变化及意义

目的： 通过比较分析结直肠腺瘤及早期恶变患者血清蛋白质的表达差异，寻找结直肠癌早期诊断的血清标记物。方法：建立结直肠腺瘤及腺瘤早期恶变患者血清蛋白双向电泳图谱，比较分析差异蛋白质斑点，切取酶解行MALDI-TOF／TOF质谱分析鉴定。结果：成功建立结直肠腺瘤及早期恶变患者血清蛋白双向电泳图谱，其平均蛋白质点分别为1672±73和1732±46，早期恶变组表达差异大于1.5倍的蛋白质斑点有28个，其中15个下调，13个上升；质谱分析鉴定出23个蛋白质，鉴定率达82.14%；合并重复鉴定的蛋白质，共获得的差异蛋白13种，其中8种为上调蛋白，5种为下调蛋白，分为6类，包括蛋白酶抑制剂、补体系统、免疫球蛋白、角质素、信号转导蛋白及未知蛋白。结论：蛋白质组学技术能灵敏分析结直肠腺瘤及早期恶变患者血清蛋白质的异常改变，本研究鉴定的蛋白质可能成为结直肠癌早期诊断的血清肿瘤标记物。

Identification of serum differential proteins in colorectal adenoma and early malignantly transformed adenoma by proteomics

AIM: To investigate the associated proteins and sensitive biomarkers for early diagnosis of colorectal adenocarcinoma by comparing the results of differential proteomic analysis between colorectal adenoma and early malignantly transformed adenoma. METHODS: Two-dimensional gel electrophoresis was used to define patterns of protein expressions of colorectal adenoma and early malignantly transformed adenoma. Proteins expressed differentially among groups were detected, cut out and analyzed by MALDI-TOF/TOF mass spectrometry. RESULTS: Two-dimensional protein maps of colorectal adenoma and early malignantly transformed adenoma were analyzed with gel-analysis software, an average of 1 672 spots in adenoma, 1 732 in early malignantly transformed adenoma were observed. 28 spots of a 1.5-fold change were found, including 15 proteins down-regulated and 13 up-regulated in early malignantly transformed adenoma, in which 23 proteins were identified by mass spectrometry, the rate of identification was 82.14%. 13 differential proteins were attained, 8 were up-regulated and 5 were down-regulated, which was classified to 6 categories, including protease inhibitor, complement, immunoglobulin, keratoproteins, signal transduction protein and function-unknown proteins. CONCLUSION: The changes of serum proteins in early malignantly transformed adenoma from adenoma can be identified by proteomic technology. Proteins detected in the study may provide new biomarkers correlated with biological behavior of colorectal adenocarcinoma.