非小细胞肺癌血清标志物PACAP的蛋白质组学筛选和鉴定

Proteomics-based Identification of Proapoptotic Caspase Adapter Protein as A Novel Serum Marker of Non-small Cell Lung Cancer

背景与目的早诊断早治疗可以提高肺癌的长期生存率,血清标志物可能有助于肺癌的早期诊断。本研究在组织培养的基础上,应用蛋白质组学方法筛选潜在的肺癌血清标志物。方法采用差异蛋白质组学技术对肺腺癌和肺组织培养液中的差异蛋白质进行初步鉴定。选取其中的半胱天冬酶凋亡前衔接蛋白(proapoptotic caspaseadapter protein,PACAP)做更进一步的研究,用Western blot验证PACAP在培养液上清中的表达情况并检测它在不同类型血清中的表达情况,用ELISA检测不同类型血清标本中PACAP的表达情况。结果共得到差异蛋白点19个,鉴定出14个。PACAP在双向电泳中表达差异较大,Western blot显示PACAP在肺癌组织培养液及肺癌患者血清中的表达均明显增高。ELISA显示PACAP在肺腺癌和肺鳞癌患者血清中的表达水平高于在小细胞肺癌、肺良性肿瘤和健康人血清中的水平(P<0.05)。结论 PACAP是潜在的非小细胞肺癌血清标志物。

Background and objective Early diagnosis and treatment of lung cancer contribute to a patient＇s prolonged survival.Proteomics and tissue culture were used to screen potential serum markers of lung cancer.Methods The differential proteomic technique and matrix-assisted laser desorption/ionization-time of flight mass spectrometry were used to identify overexpressed proteins from cultured tumor tissues in a conditioned medium.Paired lung tissues in a conditioned medium were used as the control group.Overexpressed proapoptotic caspase adaptor protein（PACAP） was identified using Western blot and enzyme-linked immunosorbent assay（ELISA）.Results The expression of nineteen protein spots exhibited a twofold increase compared with that in the control group.Fourteen of which were identified,including the distinctly overexpressed PACAP.Western blot analysis revealed a high level of PACAP in the lung adenocarcinoma in both tissue culture media and patients＇ serum.Overexpressed PACAP was also detected in the serum of non-small cell lung cancer patients via ELISA compared with that in the serum of small cell lung cancer patients,benign lung tumor patients,and healthy individuals（P0.05）.Conclusion PACAP is a potential serum marker of non-small cell lung cancer.