The effect of two nucleoside antitumor drugs on the proliferation and DNA methylation of human gastric cancer cells.

Fluorouracil (5-Fu) and 5-azacitidine (5-aza) are two types of nucleoside analog, which have been widely applied in the treatment of several types of cancer. However, the effect of these two types of drug on the proliferation and DNA methylation of cancer cells has not been compared in a single study. In the present study, in vitro cultured human gastric cancer cells (hGCCs) were treated with various concentrations of 5-Fu and 5-aza, and cell counting, MTT assay and methyl-sensitive amplified polymorphism were used to evaluate the resulting levels of proliferation and DNA methylation of hGCCs. The results revealed that the two drugs were able to inhibit the proliferation of hGCCs, but that the effect of 5-aza was weaker than that of 5-Fu. However, 5-aza decreased the level of DNA methylation in hGCCs, whereas 5-Fu did not alter DNA methylation. These results indicated that 5-Fu was able to more efficiently inhibit the proliferation of hGCCs than 5-aza, and that this difference may be due to differences in the anticancer mechanism of these two types of drug.