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Cancer is a serious disease threat to human life, which is one of the main treatment for radiation therapy. Conventional radiation therapy uses X, γ, electronics and other rays of the radiation dose increases with depth decays exponentially killing effect on normal tissues, resulting in severe radiation complications and sequelae. Heavy ion beams with Bragg peak, enabling high-dose region focused on the tumor site, thus effectively protecting the surrounding healthy tissue, and has a high relative biological effectiveness, efficiency and low repair, become the world's most advanced, most scientific and The most effective means of radiotherapy, is recognized as the 21st century with the best radiation rays. Since 1995, China became the United States, Germany, Japan, after the fourth to carry heavy ion cancer treatment study countries, Lanzhou Institute of Modern Physics, so the state research projects as a starting point for molecular biology, cell biology and animal testing and other large research, but few studies of oral cancer. This thesis is to explore heavy ion beam Tb of human tongue squamous cell biological effects of radiation, is designed to carry out the clinical treatment of the accumulation of experimental evidence. In this study, the use of carbon ion beam irradiation in human tongue carcinoma Tb cells at doses of 0.5,1,2,4 Gy. Cell viability by MTT assay and plotted survival curve; complex staining using Hoechst 33258/PI observed under a fluorescence microscope Tb apoptotic morphology; Western-blot assay Tb cells Bax/Bcl-2 protein expression: Use FACSCalibur flow cell analyzer Tb cell cycle, and with the X-ray irradiation for comparison, calculate the relative biological effect (RBE). Experimental results show that, Tb cells were treated with carbon ion beam irradiation, the survival rate was significantly decreased in a dose-dependent growth inhibition; Tb cells showed blue fluorescence concentrated Integrated Mission apoptotic morphology, and the percentage of apoptosis increased with radiation dose ; Western-blot showed that Bax protein levels increased gradually with the irradiation dose increased, but no longer in 4Gy group increased its expression, Bcl-2 protein is decreased with dose; Tb cells showed G 2 < / sub> / M was significantly block, block level in a dose-and time-dependent. When the radiation dose is 0.5Gy, 1Gy time, Tb peak cell block after 12h, 24h down. Tb cells in the X-ray irradiation, 2.0Gy group activates G 1 of test points, and 4,6,8 Gy group activation G 2 of test points, the irradiation dose of 6Gy, the cells G 2 arrest rate of 70%, equivalent to 2Gy heavy ion irradiation, ie relative biological effectiveness (RBE) is 3. Through this study, the following conclusions can be obtained: Heavy ion beam irradiation on human tongue squamous cell carcinoma Tb cells was inhibited in a dose-dependent manner; Tb percentage of apoptotic cells increased with the dose increased, Bax/Bcl-2 gene expression is the main mechanism. Heavy ion and X-ray radiation on cell cycle Tb different effects compared with X-rays, heavy ion beams with high biological effects.
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