Further circumstantial evidence for the involvement of aflatoxin in primary liver cancer?

Abstract

Fifty-eight percent of hepatocellular carcinomas (HCCs) from Qidong, China, contain an AGG to AGT mutation at codon 249 of the p53 tumour suppressor gene, a mutation that is rarely seen in HCCs from Western countries. The population of Qidong is exposed to high levels of aflatoxin B₁(AFB₁), a fungal toxin that has been shown to induce the same mutation in cultured human HCC cells. To investigate the role of AFB₁ and of these p53 mutations in hepatocarcinogenesis, normal liver samples from the United States, Thailand and Qidong (where AFB₁ exposures are negligible, low and high, respectively) were examined for p53 mutations. The frequency of the AGG to AGT mutation at codon 249 paralleled the level of AFB ₁ exposure, which supports the hypothesis that this toxin has a causative-and probably early-role in hepatocarcinogenesis.