HIGH PREVALENCE OF P53 GENE ALTERATIONS AND PROTEIN OVEREXPRESSION INHUMAN ESOPHAGEAL CANCER - CORRELATION WITH DIETARY RISK-FACTORS IN INDIA

Epidemiological studies have demonstrated an association between human esophageal cancer and dietary/nutritional risk factors in developing countries. We examined the expression of p53 protein in 51 cases of es ophageal squamous cell carcinomas (ESCCs) and paired normal esophageal tissues by immunohistochemistry, Alterations in the tumor suppressor gene p53 (exons 5-8) were analyzed in 51 cases of ESCC and paired norm al tissues by PCR and single-strand conformation polymorphism, p53 pro tein expression was correlated with major dietary risk factors and com mon carcinogens identified in India, Immunohistochemical analysis of f rozen esophageal tissue sections using anti-p53 monoclonal antibody (D 0-1) showed overexpression of the protein in the nuclei of epithelial cells in 39 of 51 (76%) cases, The histopathologically proven normal e sophageal tissue sections taken from a distant site from esophageal ca ncer patients did not show any detectable level of p53 immunoreactivit y. The PCR-single-strand conformation polymorphism analysis showed a m obility shift in 37 of 51 (72%) ESCCs, Intake of chilies was positivel y associated with p53 protein expression (P < 0.01) in the esophageal cancerous lesions, Our results suggest that p53 alterations are freque nt events in esophageal oncogenesis in the Indian population, which ha s dietary habits that are considerably different from those of the Wes tern population.