α粒子体外照射致SAEC细胞恶性转化及肿瘤干细胞在转化细胞中的表达

Objective: Establish the malignant transformation model of SAEC cells induced by α particle and detect the expression of tumor stem cells in transformed cells. Methods: SAEC cells were exposed to different doses (0.2、0.4、0.8、1.0、2.0Gy) of α particles by single and multiple treatment. Survival fraction was detected using plating efficiency immediately after the irradiation. Cells were cultured in SAGM in 37℃, 5% CO2 incubator for a period to measure changes in cell transformation by detection of resistance to serum and PALA, cell proliferation, independent growth in soft agar and invasion ability. The transformed cells were inoculated subcutaneously into nude mice to observe the tumor growth in vivo. CD338 and CD133 were detected by flowcytometry and immunohistochemistry. Results: Survival fraction showed a dose-dependent manner of cytotoxicity of α particle on SAEC cells. Serum resistance and PALA resistance were observed in the process of transformation. Proliferation and saturation density increased significantly four month after the first irradiation, indicating an overcome of growth contact inhibition of the cells. All the cells in the irradiated groups could form colonies in soft agar, of which the highest rate and biggest size of colony in 0.8 Gy group, with an increased invasion ability in the transformed cells. The c-myc expression increased and p53 expression decreased significantly. Three out of the five nude mice in the 0.8 Gy multiple treatment group formed tumors 4 month after inoculation, which was identified as an epithelial origin. CD338 and CD133 were increased in transformed SAEC cells and in tumor of nude mice. Conclusions: Human SAEC cells could be malignantly transformed in vitro by α particle and could form tumor in vivo in nude mice. Tumor stem cells increased in transformed cells.