Study on the relationship between DNA methylation and pathological changes in hepatocellular carcinoma and gastric cancer

The degree of total genomic DNA methylation by incubating DNA with ³ H-S-adenosylmethionine(³H-SAM)in the presence of methylase, and the pathological changes were studied in 21 cases of advanced gastric cancer and 33 hepatocellular carcinoma.The results show that the degree of total genomic DNA methylation in cancerous tissue was significantly lower than that in normal(gastric or hepatic)and paracancerous tissues(P<0.05).It is suggested that the alteration of total genomic DNA methylation in cancer cells of both gastric and hepatocellular cancer is related with the pathology of these cancers.