一种肿瘤相关抗原在食管鳞状细胞癌中的鉴定与表达

Identification and Expression of A Tumor-associated Antigen in Esophageal Squamous Cell Carcinoma

目的寻找食管鳞状细胞癌的肿瘤相关抗原。方法采用二维凝胶电泳法分离食管鳞状细胞癌组织蛋白,转至PVDF膜上,与食管鳞状细胞癌患者和健康人血清分别杂交,进行Western blot分析,比较分析杂交后的差异蛋白,将差异蛋白经胰酶酶解后行质谱鉴定;采用免疫组织化学方法对鉴定的肿瘤相关抗原进行验证。结果食管鳞状细胞癌患者血清阳性杂交信号较多,其中相对分子质量为28 800的阳性率为60%(12/20),而对照血清阳性率为5%(1/20),两组相比差异有统计学意义(P<0.01)。经基质辅助激光解析/电离飞行时间质谱鉴定,该蛋白为磷酸甘油酸变位酶1(PGAM1)。免疫组织化学结果显示,PGAM1在食管鳞状细胞癌组织中的表达主要集中在细胞浆和细胞核,且明显高于癌旁正常组织。结论 PGAM1可能是食管鳞状细胞癌的肿瘤相关抗原。

Objective To search for novel tumor associated antigens （TAA） in esophageal squamous cell carcinoma （ESCC）. Methods The proteins extracted from tissues of ESCC were separated by two dimen- sional polyacrylamide gel electrophoresis and transferred to PVDF membrane. Sera from ESCC patients and healthy individuals were used for primary antibodies for Western blot analysis. The differential spots were ex- cised for trypsin hydrolysis and the tryptic peptides were analyzed by matrix-assisted laser disorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. The identified TAA of ESCC was validated by immunohis- tochemical staining （IHC）. Results Sera from ESCC patients yielded multiple positive spots, and one 28 800 Da protein that exhibited positive reactivity with 60% （12/20） sera of ESCC patients and only 5% （1/20） sera of healthy controls （P 〈 0. 01 ）. The 28 800 Da protein was identified as phosphoglycerate mutase 1 （ PGAM1 ） by MALDI-TOF-MS. Immunohistochemical analysis showed that PGAM1 was located in both cytoplasm and nucleus, and had a higher expression in cancer tissues. Conclusion PGAM1 maybe a candidate of ESCC.