胃癌及其癌前病变中ras, c-erbB-2, p53癌基因产物的表达

目的 探讨胃癌及其癌前病变中ras,c-erbB-2,p53癌基因蛋白产物的表达分布特点及其在胃癌发生发展中的作用。方法 应用免疫组化ABC方法，对58例胃癌、31例胃粘膜上皮异型增生和11例正常胃粘膜组织中，鼠抗人mAb ras基因p21蛋白、兔抗人c-erbB-2原癌基因产物多克隆抗体p185，鼠抗人mAb p53蛋白进行了检测。结果p21在正常胃粘膜和轻、中、重度异型增生和胃癌中的表达率分别为27．3％，30．0％，46．2％，75．0％和72．4％；其表达率在重度异型增生和胃癌中显著高于正常胃粘膜和轻、中度异型增生（P＜0．05）；p185在正常胃粘膜和轻、中度异型增生中无表达，在重度异型增生和癌中的阳性表达率分别为25．0％，18．9％，各组间无显著性差异（P＞0．05）；p53仅在癌中有表达，表达率29．3％，明显高于非癌组织（P＜0．05）。胃癌中两种以上癌基因蛋白同时表达率明显高于非癌组织（P＜0．05）。结论 ras基因可能作用于胃癌发生的早期阶段，c-erbB-2,p53基因可能作用于胃癌发生的较晚期。并认为胃癌发生需要多基因协同作用。

Expression of ras p21, p53 and p185 oncoproteins in cancer and precancerous lesions of stomach

AIM To investigate the expression and distribution features of p21, p53 and p185 oncoproteins in gastric cancer and its precancerous lesions. METHODS Immunohistochemical method was used to measure tissues of 58 gastric cancer and 31 gastric mucosa dysplasia. RESULTS Positive rate of p21 in mild, moderate, severe dysplasia and cancer of stomach was 3/10 (30.0%), 6/13 (46.2%), 6/8 (75 0%) and 42/58 (72.4%) respectively; the positive rate of p185 in severe dysplasia and cancer of stomach was 2/8 (25 0%) and 11/58 (18.9%) resprectively; p53 expression was only in cancer 17/58 (29.3%). The positive percentage of ras p21 in severe dysplasia was significantly higher than that of normal mucosa or mild dysplasia ( P <0.05), approaching the level in carcinoma ( P >0.05). The positive expression percentage of p53 in gastric carcinoma was significantly higher than that of non carcinomarous tissue ( P <0 05). There were more than two kinds of oncogenes overexpressed in gastric carcinoma ( P <0.05). CONCLUSION Over expression of p21, p185, p53 may play an important role in the onset and development of gastric carcinoma; the ras gene product may be correlated to the events happenning in the early period of gastric carcinogenesis, while p185 and p53 gene proteins may be related to the later period of gastric carcinogenesis. It is also suggested that severe dysplasia has already possessed some characteristics of carcinoma and the development of a gastric carcinoma needs the synergistic action of several oncogenes.