57kD肺癌抗原的分离纯化、免疫抗体的制备与各型肺癌免疫组织化学分析

目的制备肺癌抗原和抗体。方法用胰蛋白酶酶解肺癌细胞膜取得多肽混合物，经琼脂糖凝胶和纤维素层析柱分离、纯化，获取肺癌表面抗原，再用电泳、Ｗｅｓｔｅｒｎ印迹法确定其性质。用此抗原免疫动物制备相应抗体，并用免疫组织化学方法对８５例肺癌、１０例正常肺和１８例非癌性肺病进行测定。结果此抗原为等电点５．６、分子量为５７０００（５７ｋＤ）的膜蛋白。正常肺和非癌性组织中此抗原表达很低，呈阴性表达；肺癌阳性表达率为８０％，其中鳞癌、腺癌、小细胞肺癌的阳性表达率分别为９４．８０％、７８．２６％和２８．５７％，高分化型鳞癌和腺癌阳性表达率在９０％以上。结论此抗原为不带糖或含糖量很低的多肽，是肺鳞癌和腺癌的共同抗原。

PURIFICATION OF 57 kD LUNG CANCER SURFACE ANTIGEN AND ITS IMMUNOHISTOCHEMICAL ASSAY

PURPOSE To prepare lung cancer surface antigen and antibody.METHODS Membranes of lung cancer cells were prepared and treated with trypsin. The mixture of polypeptides obtained passed an OM-Sepharose 4B column, a Sephadex G100 fine column, and a DEAE-cellulose 52 column in succession. A peptide product was obtained,its isoelectric point was 5. 6. By using Western blotting technique,it was found that the peptide was from a 57 kD membrane protein. 85 cases of lung cancer, 10 cases of normal lung and 18 cases of non-malignant lung disease samples were tested by the immunohistochemical method.RESULTS The gene expressions of non-malignant lung disease and normal lung tissue were all negative; the positive expression rate of lung cancer was 80%; among them, the positive expression rates of squamous lung cancer,adenocarcinoma and small cell lung cancer were 94. 80%, 78. 26 % and 28. 57 % respectively. The highly differentiated squamous lung cancer and adenocarcinoma had positive expression rates of more than 90%.CONCLUSIONS The lung cancer antigen can be directly purified from cell membranes by the above method and it may be the common antigen of both squamous carcinoma and adenocarcinoma lung cancer.