p53突变蛋白在胃癌组织中的表达及免疫电镜观察

作者应用抗ｐ５３单克隆抗体Ｐａｂ１８０１（Ａｂ２美国癌基因公司产品）对３８例手术切除的胃癌组织及癌旁胃粘膜的冰冻切片标本进行ｐ５３突变蛋白表达的检测，并进一步用胶体全免疫电镜技术对ｐ５３突变蛋白的分布特征进行观察。结果：３８例胃癌组织中，２４例有ｐ５３突变蛋白高表达，阳性率６３．２％。在对应的癌旁胃粘膜中１０例为ｐ５３的弱表达，正常组织无表达。伴有淋巴结转移的２３例胃癌标本中，１８例ｐ５３高表达（７８．３％）。免疫电镜结果表现，ｐ５３蛋白主要分布于核内染色质中，胞浆中有散在的阳性区，但以核膜周边为主，紧靠核膜。本研究结果提承胃癌的发生及其肿瘤的生物学行为与抑癌基因ｐ５３的突变密切相关，ｐ５３突变蛋白可能是通过对ＤＮＡ复制的影响而参与肿瘤的形成。

EXPRESSION OF p53 MUTANT PROTEIN AND OBSERVETION OF IMMUNOELECTRONIC MICROSCOPY IN GASTRIC CARCINOMA

By using an anti-p53 monoclonal antibody Pah1801 (Ab2, ONCOGENE SCIENCE), we have studied the expression of p53 protein in cryostatic section of tumor tissues and adjacent mucosa resected from 38 gastric carcinomas. Furthermore, the distribution of p53 was also detected with the colloid-gold immunoelectronic microscopy. The result is showed that there was high expression of p53 mutant protein in 24 out of 38 cases with carcinoma and positive rate was 63. 3% normal tissues and all the adjacent mucosa except 10 showed negative staining with p53 monoclonal antibody. These 10 adjacent mucosa were only weakly stained. The shigh expression of p53 also found in 18 out of 23 cancer patient with metastasis in perigastric lymph nodes (78. 3% ). It is found by immunoelcctronic microscopy that the p53 colloidgold granules were distributed in a great number in nuclear chromatin and a few in cytoplasm near the nuclear membrance of the cells. These findings suggest that the mutation of p53gene is closely related to the development of gastric cancer and tumor metastasis. The p53mutant protein may play an important role in tumorgenesis by affecting DNA replication.