应用表面增强激光解析电离飞行时间质谱技术筛选乳腺癌相关蛋白标志物

Application of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry in screening breast cancer markers

目的 应用表面增强激光解析电离飞行时间质谱 （SELDI-TOF-MS）技术筛选乳腺癌的特异性蛋白标志物。方法 用SELDI-TOF-MS仪及CM10蛋白芯片检测110例乳腺癌患者治疗前及100名健康对照的血清蛋白指纹图谱，应用软件自动采集数据、筛选差异表达蛋白，对表达有差异蛋白的诊断效率进行统计分析，采用多变量的Logistic回归模型校正混杂因素。结果 乳腺癌组与健康对照组相比，共有49个蛋白峰的强度差异有统计学意义（P＜0.05）。结合以前的文献，筛选出6个蛋白标志物，质荷比（M／Z）分别为3264、3968、4376、8124、8924和9180，组建成乳腺癌诊断模型，其中表达下调的蛋白M／Z有4376、8126和8924，表达上调的有3264、3968和9180。M／Z为3264、3968、4376、8126、8924的蛋白诊断乳腺癌的ROC曲线下面积分别为0.936、0.933、0.727、0.976和0.751，可作为诊断乳腺癌的标志物。M／Z为9180的蛋白与乳腺癌的TNM分期和Her-2的表达相关（P＜0.05），M／Z为8926的蛋白峰与乳腺癌淋巴结转移有一定的关系（P＜0.05）。结论 SELDI蛋白质谱技术可能有效地区分乳腺癌患者和健康人，筛选出的蛋白对乳腺癌诊断的灵敏度和特异度较高。SELDI在乳腺癌的诊断及乳腺癌特异性分子生物标志物的筛选方面具有一定的应用价值。

Objective To explore the application of serum SELDI proteomic patterns to screen breast cancer biomarkers. Methods Serum protein profiles of 110 breast cancer patients and 100 healthy controls were analyzed with surface-enhanced laser desorption/ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. The spectra were generated on weak cation exchange （WCX2） chips and protein peaks clustering and classification analyses were made using Biomaker Wizard software. Differences in protein intensity between breast cancer cases and controls were measured with the Mann-Whitney U test and adjusted for confounding in a multivariate logistic regression model. Results Forty-nine of these proteins were found to have statistically differential expression levels between breast cancer and normal control sera （P 〈 0.05）. Based on literatures reported, six protein biomarkers, with mass-to-charge ratio （M/Z） （4376, 8126, 8924, 3264, 3968, and 9180） were selected. Proteins with M/Z 4376, 4126, and 8924 were statistically significantly decreased in breast cancer cases compared to those in healthy controls （P 〈 0.05）. Proteins with M/Z 3264, 3968, and 9180 were significantly increased in breast cancer cases compared to those in healthy controls,Protein with M/Z 9180 was associated with TNM stage and Her-2 expression in breast cancer （P 〈 0.05）. Protein with M/Z 8926 was related with lymph node metastasis （P 〈0.05）. Conclusion These results suggest that serum SELDI protein profiling can distinguish breast cancer patients from normal subjects with relatively high sensitivity and specificity. SELDI-TOF-MS plays a valuable role in the diagnosis of breast cancer and the discovery of new tumor-specific protein biomarkers.