p53突变蛋白在胃癌及癌旁组织中的表达

THE EXPRESSION OF MUTANT P53 GENE IN GASTRIC CARCINOMA

应用ＡＢＣ免疫组化方法及核仁形成区（ＮＯＲ）银染色，对３８例手术切除的胃癌及癌旁胃粘膜组织冰冻切片标本进行了ｐ５３突变蛋白表达的检测及ＡｇＮＯＲ颗粒计数。结果：３８例胃癌标本中２４例ｐ５３突变蛋白高表达，阳性率为６３．２％；３８例癌旁胃粘膜中１０例ｐ５３突变蛋白弱表达。伴有淋巴结转移的２３例胃癌标本，１８例（７８．３％）ｐ５３蛋白高表达。ｐ５３表达阳性的胃癌组织，每核ＡｇＮＯＲ颗粒平均数（９．９±２．１４）较 ｐ５３表达阴性者（７．２±１．６８）明显增多，差异有显著性（Ｐ＜０．０１）。本实验结果提示：抑癌基因ｐ５３的突变是肿瘤增生异常活跃的因素之一，在胃癌的发生中可能是一种比较常见的基因改变，并可能与胃癌的转移有关。

Loss or inactivation of p53 gene──a suppressor oncogene has been considered to be one of theimportant mechanisms in the development of human tumors. One of the evidences for mutation ofallelic gene of p53 is the identification of p53 protein concentrated in the nuclei ofrelated cells. By usingABC immunohistochemical method, we studied the expression of p53 in cryostatic sections of the tumortissue and adjacent mucosa resected from 38 patients with gastric cancer. p53 was fourid to be positivein the nuclei with intensive staining in 24 out of 38 cases with carcinoma (63.2%).p53 positive cells weredistributed diffusively in the cancer tissue.All the adjacent mucosa specimens except 10 were negativelystained with p53 monoclonal antibody.These 10 specimens including 3 with dysplasia and 4 withmetaplasia were only weakly stained.p53 was also found to be positive in 18 out of 23 cancer patientswith metastasis in perigastric lymph nodes (78.3%).We also studied in the same section the nucleolarorganizer region一associated proteins(AgNORs) with using silver staining technique to find if there isany relationship between p53 gene mutation and the activity of rRNA transcription of tumor cells. Thenumber of AgNORs dots per nucleus detected in gastric cancer sections with positive staining of p53(9.9+2. 14) was greater than those with p53 negative staining(7.2+l.68).There was a significant statisti-cal difference between the two groups (P<0.01).The results suggest that p53 mutation may be one ofthe genetic events in the development of gastric carcinoma and may play an important role in tumor in-vasion and metastasis. The results also show that p53 gene inactivation may be one of the factors of fa-voring proliferation of tumor cells.