Effect Of The Demethylating Agent 5-Aza-2'-deoxycytidine On SW48 Human Colonic Carcinoma Cell Lines

[Objective]To investigate the effect of DNA methylation on tumor suppressor gene RASSF1A in SW48 human colonic carcinoma cell line by DNA methyltransferase inhibitor, 5-Aza-2,-deoxycytidine(5-Aza-cdR), and to detect the changes of cell cycle by using flow cytometry, the possibility of its application in clinical treatment.[Methods]SW48 colonic carcinoma cell lines were treated with 0.4μmol/L,1.6μmol/L, 6.4μmol/L, 25.8μmol/L, 102.4μmol/L 5-Aza-CdR. Activation in cell growth after being treated with different density of 5-Aza-cdR was observed by MTT. The cell cycle and apoptosis were analyzed by flow cytometry. The change in expression of the tumor suppressor gene RASSF1A mRNA was observed by using RT-PCR before and after 5-Aza-cdR treatment.[Results](1) By MTT, 5-Aza-2,-deoxycytidine at a concentration of 1.6μmol/L could apparently inhibit the proliferation of SW48 colonic carcinoma cell lines . The above effects of 5-Aza-2,-deoxycytidine were concentration and time dependent in a range.(2) The number of cells in the G0/G1 was increased ,5-Aza-2,-deoxycytidine blocks cell cycle at G1 phase and apoptotic rate was also increased .The above effects of 5-Aza-2,-deoxycytidine were concentration and time dependent in a range. (3) The gene was reactivated by 5-Aza-2,-deoxycytidine in SW48 cell line not expressing RASSF1A.[Conclusion]5-Aza-2,-deoxycytidine can inhibit the growth of SW48 , and increase the apoptosis by eliminating the promotor methylation state of some tumor inhibitory genes.