Experimental study of apoptosis in C6 rat glioma model induced by cryotherapy

OBJECTIVE:To explore the mechanism of killing tumor cells by observing the C6 rat glioma cell apoptosis after cryotherapy. METHODS: By establishing the C6 rat glioma models, after cryotherapy, TUNEL and Flow cytometry were employed to inspect the number of apoptotic cells and apoptotic rate respectively. RESULTS: Cryotherapy can induce cell apoptosis. Necrosis was shown in the central of tumor cells and apoptosis was observed in the peripheral zone. The number of apoptotic cells detected by TUNEL method at 24, 48 and 72 h after freezing, which compared with that in the control group, P value was 0.323, 0.001 67 and 0.037 respectively. The apoptotic index detected by Flow cytometry at 24, 48, 72 h ours after freezing, which compared with that in the control group, P value was 0.025 4, 0.006 4 and 0.031 respectively, All the difference were statistical significance, P0.05. This change was particularly evident at 48 h after freezing, P0.01, The apoptotic peak was occurred during 24-48 hours after cryotherapy. CONCLUSIONS: Inducing apoptosis was also one of the mechanisms of killing tumor cells treated by cryotherapy. But the molecular mechanism of Induced apoptosis must be further investigated.