Cancer-associated alterations of blood group antigen expression in human colorectal polyps.
Cancer-associated alterations of blood group antigen expression in human colorectal polyps.
复制标题
人类结直肠息肉中与癌症相关的血型抗原表达的改变。
作者：
S. Itzkowitz;M. Yuan;L. Ferrell;A. Palekar;Y. Kim
人类结直肠癌组织可能表现出几种血型物质（BGS）表达改变的模式：在远端结肠重新出现A、B、H或lewis抗原；结肠近端BGS缺失伴或不伴前体物质积聚；BGS在结肠近端或远端表达不相容。本研究评估了具有不同恶性潜能的结直肠息肉的这些癌症相关改变。对于ABH抗原，被认为没有恶性潜能的增生性息肉（HPs）没有表现出不相容性，只有少数病例表现出BGS的再现或缺失。然而，腺瘤性息肉（APs）在27%的息肉中经常重新表达ABH抗原或表达不相容的BG-A或B；一个标本显示BG-B缺失。在hp中未发现前体表达，但在APs中经常观察到。远端息肉ABH的再次出现与发育不良程度的增加有显著相关性，但与息肉大小或组织学类型无显著相关性。在Lewis抗原表达方面，几乎所有远端息肉均出现Lewisb重现，且Lewisa-Lewisb共表达也很常见。Lea缺失经常被注意到，特别是在HP中，但这一发现的意义尚不清楚。本研究表明，在结直肠癌组织中发生的几种抗原改变也出现在癌前息肉中，并且经常出现在肿瘤过程的早期阶段。观察到pg - a或B的不相容表达仅发生在AP和癌组织（以及癌旁粘膜）中，而不发生在胎儿结肠粘膜、成人正常结肠粘膜或HP中，这表明这可能是癌症特异性现象。
Human colorectal carcinoma tissues may exhibit several patterns of altered blood group substance (BGS) expression: reappearance of A, B, H, or Lewisb antigens in distal colon; deletion of BGS in the proximal colon with or without precursor substance accumulation; and incompatible BGS expression in proximal or distal colon. The present study evaluated these cancer-associated alterations in colorectal polyps with different malignant potential. With respect to ABH antigens, hyperplastic polyps (HPs), considered to have no malignant potential, did not exhibit incompatibility and only a few cases demonstrated BGS reappearance or deletion. Adenomatous polyps (APs) however, frequently reexpressed ABH antigens or expressed incompatible BG-A or B in 27% of polyps; one specimen demonstrated BG-B deletion. Precursor expression was not found in HPs but was frequently observed in APs. Reappearance of ABH in distal polyps was significantly correlated with increasing grade of dysplasia, but was not significantly correlated with polyp size or histological type. With respect to Lewis antigen expression, Lewisb reappearance occurred in almost every distal polyp, and Lewisa-Lewisb coexpression was also quite common. Lea deletion was frequently noted, especially in HP, but the significance of this finding is unclear. This study indicates that several antigenic alterations that occur in colorectal cancer tissues also appear in premalignant polyps, and often in early stages of the neoplastic process. The observation that incompatible expression of BG-A or B occurs only in AP and cancer tissues (as well as mucosa adjacent to cancer) but not in fetal colonic mucosa, adult normal colonic mucosa, or HP, suggests that this may be a cancer-specific phenomenon.