抑癌基因p16在胃癌及胃癌前病变组织中的表达

目的探讨p16基因表达与胃癌发生及胃癌生物学行为的关系。方法应用抗p16蛋白单克隆抗体,采用免疫组化ABE方法对10例正常胃粘膜、16例胃粘膜轻度异型增生、12例中度异型增生、14例重度异型增生、16例早期胃癌及52例进展期胃癌进行了标记分析。结果正常胃粘膜全部表达p16蛋白,随着胃粘膜病变的进展,p16蛋白的阳性率逐渐下降。轻、中、重度异型增生阳性率分别为87.5％、75％、50％,早期胃癌及进展期胃癌的阳性率分别为43.8％和38.5％。p16蛋白在轻度异型增生中的阳性率分别与重度异型增生、早期胃癌及进展期胃癌相比,差异均有显著性(P<0.05);中度异型增生的阳性率显著高于进展期胃癌(P<0.05);而淋巴结转移组的阳性率明显低于淋巴结未转移组(22.2％vs 51.2％,P<0.05)。结论胃粘膜的癌变过程与抑癌基因p16表达缺失密切相关,p16蛋白可作为判断胃癌生物学行为的一个有用指标。

Expressin of p16 protein in gastric carcinoma and precancerous lesion

Objective To study the role of p16 gene in gastric carcinogenesis and the relation between the gene expression and the behavior of gastric carcinoma . Method p!6 protein was detected with immunohistochemical ABC method in 10 normal gastric mu-cosas, 42 gastric mucosal dysplasias , 16 early and 52 advanced gastric carcinomas . Results All normal gastric mucosas were positive for p16 protein. The positive rates in dysplasias and gastric carcinomas decreased gradually with the progession of lesions . The positive rates were 87.5% , 75% and 50% in slight , moderate and severe dysplasias respectively, 43.8% positive rate was found in early gastric carcinomas and 38.5% positive rate in advanced cases.The rate in slight dysplasias was significantly higher than that in severe dysplasias , early and advanced gastric carcinomas, (P<0.05 respectively); and the rate of moderate dysplasias was signicantly higher than that of advanced gastric carcinomas (P<0.05). The rate of the group with lymph node metastasis was much lower than that without metastasis (22.2% vs 51.2%, P<0.05).Conclusion The loss of p16 expression is closely related to gastric mucosal carcinogenesis, and p16 protein may be an useful marker for the assessment of the biological behavior of gastric carcinoma.