p53 inactivating mutations in Chinese nasopharyngeal carcinomas

Previously a low frequency of p53 mutations was detected in nasopharyngeal carcinoma (NPC) using molecular techniques to screen for mutations, yet imm unohistochemical staining revealed a high frequency of p53 aberrant protein s. These findings might be attributed to the occurrence of p53 mutations ou tside the common hot spots and/or the inactivation of the protein through i nteractions with cellular or viral proteins. Using a previously established simple and sensitive p53 yeast functional assay, we blindly screened 25 na sopharyngeal biopsies for p53 mutations from exons 4 to 11, p53 was mutated in 27.3% of NPC specimens and in 0% of the nasopharyngeal biopsies from pa tients with non-malignant diseases. Two p53 mutations were detected in exon 7 and two were detected in exon 8. Interestingly, the exon 8 mutations obs erved in NPC lie in codons which appear to be hot spots for mutations in ot her head and neck cancers. (C) 1998 Elsevier Science Ireland Ltd. All right s reserved.