Study of the deletion mutation of glutathione transferase M1 gene and its role in susceptibility to hepatocellular carcinoma

Objection: To investigate the glutathione S transferase Ml (GSTM1) gene inherent deletion and its relation to prevalence of hepatocellular carcinoma (HCC) in Guangxi, China. Methods: The GSTM1 gene polymorphism of 120 HCC patients and 100 healthy subjects both from the same high aflatoxin B₁ (AFB₁) contaminated area were detected using PCR technique with special primers. Another 40 patients from AFB₁ low risk area were also tested. Results: In HCC high risk area, it was found that the frequencies of GSTM1 null genotype in HCC patients and healthy subjects were 59% and 51% respectively, with no significant difference. However, the frequency of GSTMl-null genotype in control group from AFB₁ low risk area was lower than those from high risk area (P<0.01). Conclusion: Populations in this HCC endemic region show a higher rate of GSTMl-null genotype, which may be partially responsible for the susceptibility to AFB₁ induced HCC. But the detoxification effect of GSTM1 alone is not sufficient to resist the genetic toxicity of AFB₁, especially in those people who expose to excess AFB₁. The GSTM1 gene deletion would not be suitable as an independent predictor of susceptibility to HCC. Foundation item: This work was supported by the National Science Foundation of China (No. 39860032) and a grant from the Department of Education of Guangxi Province (98-2-8). Biography: MA Yun (1963-), professor of pathology, physician in charge, Guangxi Medical University, majors in cancer etiology and fungi pathology.