摘要目的 了解相同剂量不同剂量率X线照射对非小细胞肺癌(NSCLC)细胞迁移的影响,以期为临床制定放疗计划提供一定的实验依据.方法 将人NSCLC细胞株A549进行培养,采用直线加速器行X线单次照射,总剂量为6 Gy,剂量率分别为1、2、4、6 Gy/min,照射后立即将单层贴壁细胞划痕,分别于划痕后0、24 h在显微镜下进行拍照,测量痕道宽度.结果划痕后24 h,未照射对照组细胞的痕道宽度为(640.7±8.1)μm,不同剂量率X线照射后细胞的痕道宽度不同,以1 Gy/min和6 Gy/min剂量率X线照射细胞的痕道最宽[(691.4±7.6)μm和(691.8±12.1)μm],4 Gy/min照射细胞的痕道宽度次之[(666.2±1.3)μm],与未照射对照组比较差异均有统计学意义(均P<0.01),表明对A549细胞迁移运动能力的抑制作用明显;而2 Gy/min照射细胞的痕道宽度为(643.5±6.8)μm,与对照组比较差异无统计学意义(t=-0.336,P=0.742).结论X线照射对人NSCLC A549细胞迁移能力的影响与剂量率有关,相同剂量不同剂量率对细胞迁移的影响存在明显差异.选择适合的剂量率进行照射,可能有助于提高肿瘤的放疗效果.

abstractsObjective To explore the effect of dose rate of X-rays on migration of non-small cell lung cancer (NSCLC) cells and provide the experimental basis for developing radiotherapy scheme. Methods Human NSCLC cell line A549 was cultured and irradiated with X-rays at dose of 6 Gy from a linear accelerator. The dose rates of 1, 2, 4 and 6 Gy/min were selected. Monolayer adherent cells were scratched and photographed at 0 hour and 24 hours under a microscope to measure the scratch width. Results After 24 hours, the scratch width of nonirradiated control cells was (640.7±8.1)μm. The scratch widths of cells were different when cells were irradiated with X-rays of various dose rates. Scratch widths were the largest in cells irradiated at dose rates of 1 Gy/min [(691.4±7.6)μm] and 6 Gy/min [(691.8±12.1)μm]. The scratch width was (666.2±1.3) μm of X-rays at 4 Gy/min, and there were significant differences compared with nonirradiated group (all P< 0.01), which suggested that inhibitory effect of X-rays at dose rates on A549 cell migration was obvious. However, the scratch width of cells irradiated at 2 Gy/min [(643.5 ±6.8) μm] had no difference compared with the control cells (t=-0.336, P=0.742). Conclusions The effect of X-rays irradiation on cell migration of human NSCLC cell line A549 is related with irradiated dose rate. The effect of different dose rates on cell migration is significantly different. Selecting appropriate dose rates for irradiation may help to improve the efficacy of radiotherapy.