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 dimensional 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 excised 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.%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.
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