OBJECTIVETo investigate the impact of 5-aza-2'-deoxycytidine(5-aza-CdR) combined with imatinib on the proliferation, motility, invasion, and apoptosis of gastrointestinal stromal tumors(GIST) cells in vitro.

METHODSMTT assay was used to investigate the effect of the two agents on proliferation of GIST882. Plate colony forming assay was used to determine the number of colony-forming. Motility and invasion abilities were tested to evaluate the inhibitory effect of each agent. Flow cytometry was used to observe apoptosis and cell cycle.

RESULTS5-aza-CdR or imatinib effectively inhibited the growth of GIST882 cells in concentration- and time-dependent manner. The inhibitory rate of combined treatment using 5-aza-CdR and imatinib was significantly higher than that of 5-aza-CdR or imatinib alone(P<0.05). After treatment for 48 h, the apoptosis rates of 5-aza-CdR group (1000 μg/L) and imatinib group (100 μmol/L) were (11.7±1.2)% and (14.6±0.8)%, respectively. Compared with the control group (2.8±0.3)%, the difference was statistically significant(P=0.000). Furthermore, the difference in apoptosis rate was significant between combined treatment group (19.4±1.1)% and single drug treatment group(vs. 5-aza-CdR group, P=0.000, vs. imatinib group, P=0.013). 5-aza-CdR raised G0/G1 ratio and reduced S ratio of GIST882. Imatinib and combined group had no apparent influence on the cell cycle of GIST882 cells.

CONCLUSION5-aza-CdR may be a potential agent of GIST treatment in the near future.