IFITM3过表达降低黑色素瘤细胞的放射敏感性

Overexpression of IFITM3 decreases radiosensitivity of melanoma cells

目的:探讨干扰素诱导的跨膜蛋白3(IFITM3)过表达对黑色素瘤细胞放射敏感性的影响及可能的机制。方法:建立稳定过表达IFITM3的黑色素瘤细胞株及对照组并验证,通过Western Blot检测其IFITM3的表达量以及照射后细胞LC3的表达量,通过克隆形成实验检测照射后的细胞存活能力,细胞增殖实验评价细胞增殖能力,免疫荧光实验评价照射后的细胞DNA损伤;建立黑色素瘤小鼠移植瘤模型,绘制照射后的肿瘤生长曲线以评价IFITM3的体内放射抵抗效应。结果:稳定过表达IFITM3的黑色素瘤细胞株B16F1-IFITM3建立成功,照射后黑色素瘤细胞中的IFITM3表达量显著增高(P<0.05),细胞受照射后的克隆能力和增殖能力显著增强(P<0.05),DNA损伤及自噬水平显著下降(P<0.05),过表达组小鼠移植瘤受射线照射后生长速度无明显减低(P>0.05)。结论:IFITM3过表达能够降低黑色素瘤细胞的放射敏感性,其机制与减少放射治疗中的DNA损伤以及降低细胞自噬水平有关。

Objective:To explore the effect and the possible mechanism of interferon-induced transmem-brane proteins 3(IFITM3)overexpression on radiosensitivity of melanoma cells.Methods:The melanoma cell lines and the control group with stable overexpression of IFITM3 were established and verified.The endogenous expression of IFITM3 and the expression of LC3 in the cells after radiotherapy were detected by Western Blot.The cell survival ability after radiotherapy was detected by cell clone formation experiment,and the cell proliferation ability was evaluated by cell proliferation experiment.Immunofluorescence was used to evaluate the DNA damage of cells after irradiation.In order to evaluate the radiation resistance effect of IFITM3 in vivo,we established the xenograft model of melanoma mice and plotted the tumor growth curve after radiotherapy.Results:The melanoma cell lines with stable overexpression of IFITM3 were established successfully.The expression of IFITM3 in B16F1 cells and B16F1-IFITM3 cells was significantly increased after irradiation(P<0.05),and the cloning ability and proliferation ability of B16F1-IFITM3 cells were significantly enhanced after radiotherapy(P<0.05).The levels of DNA damage and autophagy decreased significantly(P<0.05).After irradiation,the tumor growth of transplanted mice in experimental group was not significant compared with control group(P>0.05).Conclusion:Overexpression of IFITM3 can reduce the radiosensitivity of melanoma cells.The presumption is that the DNA damage is decreased in radiotherapy and the autophagy level is also decreased by overexpression of IFITM3.