Effect Of 5-Aza-2'-deoxycytidine On Biological Behavior Of Gastrointestinal Stromal Tumors Cell Line GIST882

Objective: To investigate the effect of methylation inhibitor 5-Aza-2'-deoxycytidine(5-Aza-CdR) on biological behavior of gastrointestinal stromal tumor cell line GIST882 and thecombination effect with Imatinib(Glivec),explore the possibility of its application in clinicaltreatment.METHODS: Human gastrointestinal stromal tumors cell line GIST882 were treated with1ng/mL,10 ng/mL,100 ng/mL,1000 ng/mL 5-Aza-CdR and 0.1μM,1μM,10μM,100μMImatinib. (1)MTT,soft agar colony formation and plate colony forming assays were used todetect cell proliferation and growth. The combination effect of 5-Aza-CdR and Imatinib wasassessed by Weeb Coefficient method. (2)Migration and movement capacity using scratchhealing experiment, invasion using transwell assay. (3)Flow cytometer was used to observeapoptosis and cell cycle. (4)The expression of Caspase9 and Bcl-2 were detected byimmunocytochemistry.RESULTS: (1)5-Aza-CdR inhibited the growth of GIST882 cells in a concentration- and timedependentmanner (P<0.05), and weakened the ability of migration and invasion capacities. Theabove effects of combined treatment with 5-aza-CdR and imatinib was more significant than thatof 5-aza-CdR or imatinib alone(P<0.05). (2) The number of cells in the G0/G1 was increased,5-Aza-CdR blocks cell cycle at G1 phase and apoptotic rate was also increased. The differenceof apoptosis rate between combined treatment group and single drug treatment group wassignificant (P<0.05). Imatnib and combined group had no apparent effect on the cell cycle ofGIST882 cells(P>0.05). (3)Immunocytochemical analysis indicated that the expression ofcaspase9 protein was up-regulated after being exposed to 5-Aza-CdR while the expression ofBcl-2 protein was down-regulated(P<0.05).CONCLUSION: 5-Aza-CdR can inhibit proliferation of GIST882 cells and induce apoptosis,itsanti-tumor activity and the synergistic effect with imatinib may be applicable on the treatment ofGIST.