[The expression of mutant p53 gene in gastric carcinoma]

Loss or inactivation of p53 gene--a suppressor oncogene has been considered to be one of the important mechanisms in the development of human tumors. One of the evidences for mutation of allelic gene of p53 is the identification of p53 protein concentrated in the nuclei of related cells. By using ABC immunohistochemical method, we studied the expression of p53 in cryostatic sections of the tumor tissue and adjacent mucosa resected from 38 patients with gastric cancer. p53 was found to be positive in the nuclei with intensive staining in 24 out of 38 cases with carcinoma (63.2%). p53 positive cells were distributed diffusively in the cancer tissue. All the adjacent mucosa specimens except 10 were negatively stained with p53 monoclonal antibody. These 10 specimens including 3 with dysplasia and 4 with metaplasia were only weakly stained. p53 was also found to be positive in 18 out of 23 cancer patients with metastasis in perigastric lymph nodes (78.3%). We also studied in the same section the nucleolar organizer region-associated proteins (AgNORs) with using silver staining technique to find if there is any relationship between p53 gene mutation and the activity of rRNA transcription of tumor cells. The number 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 + 1.68). There was a significant statistical difference between the two groups (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)