Ho J J, Bi N, Yan P S, Yuan M, Norton K A, Kim Y S
Gastrointestinal Research Laboratory, Veterans Administration Medical Center, San Francisco, California 94121.
Cancer Res. 1991 Jan 1;51(1):372-80.
Although mucins have been found to be useful in the diagnosis of pancreatic cancer, the carbohydrate and peptide structures of pancreatic mucins are still not well characterized. Monoclonal antibodies were produced using mucins purified from xenografts of a human pancreatic cancer cell line as the immunogen. One of these, Ia3, reacted with almost all pancreatic, gastric, and colorectal carcinomas examined by immunoperoxidase staining, but with few normal tissues. Ia3 antigen was elevated in sera of 50.4% of individuals with gastrointestinal tumors, but its levels did not correlate with those of CA15-3, CA19-9, or DU-PAN-2. Serum Ia3 antigens migrated more slowly in sodium dodecyl sulfate-polyacrylamide gel electrophoresis than the polymorphic epithelial mucins recognized by DF3 or 115D8. Ia3 reacted only with native, and not with partially deglycosylated, pancreatic cancer xenograft mucins. Periodate or neuraminidase treatment destroyed this reactivity, but protease had little effect. The antigen recognized by another antibody, Nd2, was not detected in normal pancreatic, colonic, or gastric tissues but was present in approximately 60% of the pancreatic and gastric carcinomas examined. Nd2 reactivity with native and partially deglycosylated mucin was lost after pretreatment with protease and beta-mercaptoethanol. We conclude that, while Ia3 reacts with carbohydrates, Nd2 reactivity appears to be dependent on the integrity of the mucin protein core. The antigenic determinants of Ia3 and Nd2 are different from those of B72.3, CA19-9, DU-PAN-2, SPan-1, and several breast cancer mucin-directed antibodies. These results suggest that the malignancy-associated structures identified by Ia3 and Nd2 may provide new information on the carbohydrate and peptide structure of pancreatic cancer mucins.
尽管已发现粘蛋白在胰腺癌诊断中有用，但胰腺粘蛋白的碳水化合物和肽结构仍未得到很好的表征。使用从人胰腺癌细胞系异种移植瘤中纯化的粘蛋白作为免疫原制备单克隆抗体。其中一种抗体Ia3，通过免疫过氧化物酶染色与几乎所有检测的胰腺癌、胃癌和结直肠癌发生反应，但与很少的正常组织发生反应。在50.4%的胃肠道肿瘤患者血清中Ia3抗原升高，但其水平与CA15-3、CA19-9或DU-PAN-2的水平无关。在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中，血清Ia3抗原的迁移速度比DF3或115D8识别的多形性上皮粘蛋白慢。Ia3仅与天然胰腺癌异种移植瘤粘蛋白发生反应，而不与部分去糖基化的粘蛋白发生反应。高碘酸盐或神经氨酸酶处理会破坏这种反应性，但蛋白酶影响很小。另一种抗体Nd2识别的抗原在正常胰腺、结肠或胃组织中未检测到，但在所检测的约60%的胰腺癌和胃癌中存在。用蛋白酶和β-巯基乙醇预处理后，Nd2与天然和部分去糖基化粘蛋白的反应性丧失。我们得出结论，虽然Ia3与碳水化合物发生反应，但Nd2的反应性似乎取决于粘蛋白蛋白核心的完整性。Ia3和Nd2的抗原决定簇与B72.3、CA19-9、DU-PAN-2、SPan-1以及几种乳腺癌粘蛋白导向抗体的抗原决定簇不同。这些结果表明，由Ia3和Nd2鉴定出的与恶性肿瘤相关的结构可能为胰腺癌粘蛋白的碳水化合物和肽结构提供新信息。
