PI3K/Akt/mTOR通路抑制剂提高宫颈癌对放疗敏感性的研究

Dual inhibition of the PI3K/Akt/mTOR pathway increases tumor radiosensitivity on cervical cancer

目的探讨胞内磷脂酰肌醇激酶(PI3K)/蛋白激酶B(Akt)/mTOR通路抑制剂BEZ235和常规放疗联合用于宫颈癌的抗肿瘤作用。方法 Hela细胞增殖抑制试验分成3个组别为BEZ235单独作用组(BEZ235_(增殖)组)、放射治疗单独作用组(R_(增殖)组)及BEZ235合并放射治疗组(R_(增殖)+BEZ235_(增殖)组)以测定半抑制浓度。迁移抑制试验(划痕试验)分成4组为溶剂对照组、R_(迁移)组(4 gy放射治疗)、BEZ235_(迁移)组(1μmol/L BEZ235)、R_(迁移)+BEZ235_(迁移)(4 gy放射治疗+1μmol/L BEZ235)加样并辐照以测定细胞迁移抑制率。蛋白质免疫印迹(WB)试验检测BEZ235合并放疗对Hela细胞的信号通路蛋白表达的影响。BEZ235合并放疗的体内抗肿瘤试验。通过这四项试验来评价单独使用BEZ235和联合放疗对人宫颈癌Hela的抑制作用。结果增殖抑制试验BEZ235作用72 h对Hela细胞抑制作用的半抑制浓度(IC_(50))为(0.49±0.30)μmol/L,联用4 gy的放疗后,对细胞抑制的IC_(50)为(0.074±0.03)μmol/L。划痕试验作用24 h,联合治疗R_(迁移)+BEZ235_(迁移)组抑制率为43.13%,划痕距离显著高于单独治疗组R_(迁移)以及BEZ235_(迁移)组。WB试验结果显示BEZ235_(WB)组能显著下调PI3K/Akt/mTOR通路主要蛋白的磷酸化活化形式,R_(WB)+BEZ235_(WB)组下调作用更明显。体内抗肿瘤试验结果显示,单独使用放疗或BEZ235都能降低移植瘤体积,合并治疗组的最终抑瘤率达到43.23%,且合并治疗组增加了肿瘤的凋亡,抑制了肿瘤的增殖。结论 BEZ235和放疗均具有抗人宫颈癌Hela的作用,放疗对宫颈癌的抗肿瘤作用能通过合并BEZ235而增强。

Objective To evaluate the in vitro effects of a PI3K/Akt/mTOR dual inhibitor BEZ235 and its combination with radiation therapy on cervical cancer.Methods The effects of BEZ235 alone and its combination with radiotherapy in Hela were evaluated by anti-proliferation assay,Western Blot assay,wound healing assay in vitro.The anti-tumor effect in vivo was also evaluated.Results BEZ253 reduced Hela cell proliferation after 72 hours(IC50 of 0.49 μmol/L).Its combination with radio therapy(4 gy) showed more tumor cells reduction(IC50 of 0.074 μmol/L).The WB showed that treated with either BEZ235 alone or with radiation therapy could down regulate the activity of PI3K/Akt/mTOR signal pathway.The combination use(radio therapy +BEZ235) could inhibit the proliferation of Hela cells,and up regulate cells apoptosis.Conclusions The PI3K/Akt/mTOR dual inhibitor BEZ235 can enhance the anti-tumor efficacy of radiation therapy.