COMPARATIVE STUDY OF ~(12)C~(6+) AND X-RAY ON CELL CYCLE PROGRESSION IN THE HUMAN TONGUE SQUAMOUS CELL CARCINOMA

[Objective] To compare the cell cycle alterations in the human tongue squamous cell carcinoma Tb in vitro after X ray and carbon ion irradiation. [Methods] Tb cells were irradiated with 12C6+ at dose 0, 0.5, 1, 2.0, 4.0Gy or with X-ray at dose 0, 2, 4, 6, 8Gy. Propidium iodide (PI) staining and flow cytometer (FCM) were used for cell cycle measure-ment. [Results] After X-ray irradiation, the Tb cell cycle was arrested in G1 stage for 2 Gy group while 4, 6 and 8 Gy groups were arrested in G2 stage. After 12C6+ irradiation, the Tb cells were inhibited significantly in G2 / M, the stagnation in-creased gradually in a dosage and time dependent manner (P﹤0. 01). The stagnation relieved at 24h for 0.5 Gy, while this phenomenon was not occurred for 2 and 4Gy groups. The rate of stagnation in 2Gy group was 70% , which was equal to 6Gy group by X-ray irradiation. [Conclusion] In comparison with X-ray group, the arrested effects of Tb cells in 12C6+ irradiate group are obvious.