IMMUNOHISTOCHEMICAL DETECTION OF P53 IN NONMALIGNANT AND MALIGNANT ORAL LESIONS ASSOCIATED WITH SNUFF DIPPING IN THE SUDAN AND SWEDEN

Immunohistochemistry was used to examine the expression of p53 in pre- malignant oral lesions and oral squamous-cell carcinomas (SCCs) from S wedish and Sudanese snuff-dippers, as well as in pre-malignant oral le sions and oral SCCs from non-snuff-dippers from the Sudan, Sweden and Norway. Of the 14 SCCs from Sudanese snuff-dippers, 21% (3/14) express ed p53. Of the 14, 60 and 41 SCCs from non-snuff-dippers from the Suda n, Sweden and Norway, 64% (9/14), 65% (39/60) and 68% (28/41) expresse d p53, respectively. A statistically significant difference in express ion of p53 was found in SCCs from Sudanese snuff-dippers compared to t hose from non-snuff-dippers from all/or any of the 3 countries. None o f the suspected pre-malignant oral lesions from Sudanese snuff dippers or non-snuff-dippers expressed p53. Only 2 out of the 15 oral fibro-e pithelial hyperplastic lesions from Swedish snuff-dippers expressed p5 3. Some of the oral epithelial dysplastic lesions, as well as the carc inoma in situ lesions from Norwegian non-snuff-dippers, expressed p53, while the oral fibro-epithelial hyperplastic lesions did not. The low relative frequency of p53 expression found in oral SCCs from snuff-di ppers compared to those from non-snuff-dippers might suggest differenc es in mechanisms of oncogenic action induced by snuff. Alternatively, the pathogenesis of malignant oral lesions from snuff-dippers may foll ow a p53-independent pathway. In view of the unusually high levers of the tobacco-specific nitrosamines (TSNA) found in the type of snuff us ed in the Sudan, investigations of p53 mutations or oncogenes are need ed. (C) 1996 Wiley-Liss, Inc.