Toll样受体4对肿瘤细胞放射敏感性的影响  

TLR4 enhances the radiation sensitivity of tumor ceils

作　　者：卢良杰[1] 董娟聪[2] 张聪[2] 金顺子[2] 单玉兴[1] 

机构地区：[1]吉林大学第一医院骨科,长春130031 [2]吉林大学公共卫生学院卫生部放射生物学重点实验室

出　　处：《中华放射医学与防护杂志》2012年第6期583-587,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金（30870584）

摘　　要：目的观察Toll样受体4（TLR4）对肿瘤细胞放射敏感性的影响。方法将体外培养的RAW264．7、Lewis、MFC、Hepa1-6、B16和NIH3T3细胞各分为假照组和5Gy照射组，采用流式细胞术检测照射24h后TLR4表达变化，从中筛选出照射后高表达和低表达TLR4的细胞，将其各自分为TAK242阻滞组、LPS刺激组和空白对照组，采用CCK-8试剂盒检测其增殖活性，用克隆形成实验计算其细胞存活分数，用AnnexinV凋亡试剂盒检测其凋亡率，用流式细胞术观察细胞周期进程的变化。结果5Gy照射24h后Lewis细胞TLR4表达水平明显高于照射前（t=-8．68，P〈0．01），MFC细胞则相反，照射后TLR4表达水平明显低于照射前（t=25．80，P〈0．01），而RAW264．7、Hepa1-6、B16细胞的TLR4表达水平比照射前有升高趋势，但无明显差异。5Gy照射后Lewis和MFC细胞的增殖活性均明显降低（t=57．62、-6．23，P〈0．01），而用TAK242阻滞TLR4后Leiws细胞增殖活性更加降低（t=5．96，P〈0．01），但MFC细胞增殖活性反而明显升高（t=4．16，P〈0．01）。5Gy照射后Lewis和MFC细胞的存活分数均明显降低（t=13．37、19．24，P〈0．01），用TAK242阻滞TLR4后Leiws和MFC细胞存活分数更加降低（t=4．90、4．42，P〈0．05）。5Gy照射后Lewis细胞的凋亡率明显高于假照组（t=-167．85，P〈0．01），阻断TLR4后明显高于单纯照射组（t=-4．73。P〈0．01）。照射后MFC细胞的凋亡率升高（t=-26．45，P〈0．01），阻断和激动TLR4其凋亡率均显著低于单纯照射组（t=8．87、-3．05，P〈0．05）。Lewis和MFC细胞受照后G0／G。期、S期细胞明显降低（t=8．68、14．80、20．31、4．48，P〈0．01），G2／M期细胞上升（t=-37．48、-13．06，P〈0．01）。两种细胞的TAK242阻断组和LPS刺激组各周期进程均无明显变化。结论Lewis细胞的TLR4高表达与其受照后的增殖活性和凋亡率变化有关，而与其周期进Objective To investigate the effects of TLR4 on the radiosensitivity of tumor cells. Methods The cell lines of RAW264.7, Lewis, MFC, Hepal-6, B16, and NIH3T3 were irradiated with 5 Gy X-rays or sham-irradiated. 24 h after irradiation, the expression of TLR4 was detected by flow cytometry. According to the TKR4 level, cells were divided into three groups： without treatment, LPS stimulation and TAK242 block. CCK-8 kit and Annexin-V Apoptosis Kit were used to detect cell proliferation, apoptosis and cell cycle distribution of each group. Results After 24 h of 5 Gy ionizing radiation, TLR4 was significantly increased in Lewis cells （ t = - 8.68, P 〈 0. 01 ） but decreased in MFC cells （t = 25.8, P 〈 0. 01 ） and had no significant changes in I-lepal-6, B16 and RAW264. 7 cells. In addition, the proliferation vitality （ t = 57.62, - 6. 23, P 〈 0.01 ） and survival fraction （ t = 13.37,19. 24, P 〈 0. 01 ） of the Lewis and MFC cells were reduced especially for the TLR4-blocked cells, and the apoptosis rates of both Lewis （ t = - 167.85, P 〈 0.01 ） and MFC cells （ t = - 26.45, P 〈 0. O1 ） were elevated. The percentages of G0/G1 phase and S phase Lewis cells were significant increased （t = 8.68, 14. 89, P 〈 0. 01 ） but its G2/M phase were reduced （ t = - 37.48, P 〈 0. 01 ）. However, the percentages of G0/Glphase and S phase MFC cells were obviously reduced （t = 20. 31, 4.48, P 〈 0.01 ） and G2/M phase increased （t = - 13.06, P 〈 0. 01 ）. For both cell lines of Lewis and MFC, the cycle distribution of TAK242 and LPS groups didn＇t change significantly. Conclusions High expression TLR4 in the Lewis cells is related to cell proliferation and apoptosis but not cell cycle distribution, and hence TLR4 could influence the radiosensitivity of tumor cells.

关 键 词：电离辐射 TOLL样受体4 肿瘤细胞 放射敏感性 

分 类 号：R730.2[医药卫生—肿瘤]