MUTATIONS AT CODON-249 OF P53 GENE IN HUMAN HEPATOCELLULAR CARCINOMASFROM TONGAN, CHINA

Codon 249 (exon 7) of the putative tumor suppressor gene p53 is a muta tional hot-spot for hepatocellular carcinoma (HCC) but not other tumor s. DNA samples from primary HCC patients from Tongan, an area of high HCC incidence in China (> 40 per 100 000 population), were analyzed fo r specific mutations in codon 249 of the p53 gene using polymerase cha in reaction (PCR)/restriction-digest methods and direct DNA sequencing . Seven of the 21 samples screened were found to have a point mutation at the third base position of codon 249 (AGG to AGT). The result is c onsistent with previous reports that the G --> T transversion is posit ively associated with the level of dietary aflatoxin B-1 (AFB(1)) cont amination, which has been implicated as one of the risk factors in Ton gan area. Of the 7 HCC patients that contained the codon 249 point mut ation, one was hepatitis B Virus (HBV)-negative. This is only the seco nd documentation of an HCC patient harboring the p53 codon 249 mutatio n, who was HBV-negative. (C) 1997 Elsevier Science B.V.