INCREASED EXPRESSION OF p62~(pan-myc) IN GASTRIC PYLORI MUCOSA BIOPSIES FROM SUBJECTS EXPOSED TO N-NITROSAMIDES

Abstract

To elucidate the possible role of myc oncogene in human gastric carcinogenesis byN-nitrosamides Methods: Expression of pan-myc in gastric biopsies of pylori and concentration of totalN-nitrosamides in fasting gastric juice samples were studied simultaneously with immunochemohistological method and liquid mobile-photohydrolysis-pyrolysis energy analyzer. Results: Ofgastric juice samples, 57. 1 % were N-nitrosamide-detectable. Evaluation of p62pan-myc in mucosal epithelial cells Was found in 6 gastric biopsies. All the 6 p62pan-myc-positive biopsies were from patients whosegastric juices were N-nitrosamide-detectable, whereas no p62 pan-myc-positive biopsy was found inthose from 15 cases whose gastric juices were N-nitrosamide-undetectab1e (P= 0. 0239). Such relationwas not observed for p21pan-ras, p185c-erbB-2, and p53mutant p53. Conclusion: These results indicate firstlythat expression of myc oncogene correlated with the exposure to N-nitrosamides in human stomach positively and myc oncogene may play a role in the early stage of human gastric carcinogenesis by N-nitrosamides.