P53 expression in human small-intestinal tumors.

Expression of the tumor supressor gene product p53 in thirteen human small intestinal tumors was examined employing an immunohistochemical technique. The level of p53 was analysed using the monoclonal antibody pAb240. Six out of thirteen tumors (46%) including one lymphoma, one angiosarcoma of the jejunum, one leiomyosarcoma, one adenocarcinoma of the small intestine and two metastatic adenocarcinomas of the colon were found to have p53 overexpression. This is the first demonstration of p53 expression in small intestinal tumors. These results indicate that the p53 gene may be involved in the pathogenesis of small intestinal tumors.