PI3K/AKT/mTOR信号影响非小细胞肺癌大分割放疗敏感性的基础研究

Radiotherapy is a main treatment of lung cancer, especially in non-small cell lung cancer (NSCLC). Compared with conventional fractionated radiotherapy, hypofractionated radiotherapy has been proved to be a powerful method in NSCLC treatment because of its convenience and better clinical efficacy. Though hypofractionated radiotherapy has achieved greatly progress in NSCLC, there are still radiation resist in tumors with unknown mechanism. PI3K/AKT/mTOR signaling pathway plays an important role in conventional fractionated radiotherapy resist, whether it can induce radiation resist of hypofractionated radiotherapy is not clear. We have acquired 6 radiation resist cell lines after irradiation A549, H1299, and H460 cells for about 3 months. The preliminary results of mRNA micro-array screening showed a closely correlation between PI3K/AKT/mTOR signaling pathway and irradiation resist in these cells. Based on the results, we aim to identify the exactly role of PI3K/AKT/mTOR signaling pathway in the resistance of NSCLC hypofractionated radiotherapy, with the following methods, such as Q-PCR, Western Blot,immunofluorescence, flow cytometry, confocal microscopy and micro-PET. The different gene expression and protein phosphorylation of the PI3K/AKT/mTOR signal pathway will be compared in tumors cells，tumor-bearing animal models，and tissue culture from NSCLC patients before and after irradiation. We also try to analyze the underline molecular mechanisms of DNA repair, glucose metabolism, cell proliferation,cell death and hypoxic micro-environmental after hypofraction radiotherapy of the tumor cells. Then we will inhibit PI3K/AKT/mTOR signal pathway with RNAi, PTEN plasmid transfection and small-molecule inhibitors to verify the radiosensitivity role of PI3K/AKT/mTOR pathway in NSCLC with hypofractionated radiation. We might provide a new target in radiation sensitivity and a modification of radiation resist in NSCLC hypofractionated radiotherapy.

放疗是非小细胞肺癌（NSCLC）治疗的主要手段，与常规分割放疗相比，大分割放疗因其便捷性和更好的疗效正在临床普及。PI3K/AKT/mTOR信号通路在常规分割放疗抗拒中具有重要作用，但能否影响大分割放疗抗拒尚不明确。本课题组利用全基因组表达谱芯片比较了多株常规和大分割放疗抗拒细胞后发现，PI3K/AKT/mTOR信号通路的多个基因存在表达差异，拟进一步采用Q-PCR、免疫印迹、RNAi、小动物PET等技术，在培养肿瘤细胞和荷瘤动物模型中研究PI3K/AKT/mTOR信号通路调控大分割放疗后肿瘤细胞DNA修复、糖代谢、增殖、死亡、乏氧微环境及分子机制；研究干预该信号通路影响NSCLC大分割放疗敏感性的可能；为放疗增敏及逆转放疗抗拒提供新靶点。同时获取NSCLC患者肿瘤组织进行裸鼠体内培养，与患者同步行大分割放疗，表达谱芯片检测信号通路相关基因变化，初步筛选预测大分割放疗敏感性的分子标记。

放疗是非小细胞肺癌（NSCLC）治疗的主要手段，与常规分割放疗相比，大分割放疗因其便捷性和更好的疗效正在临床普及。PI3K/AKT/mTOR信号通路在常规分割放疗抗拒中具有重要作用，但能否影响大分割放疗抗拒尚不明确。本课题组利用全基因组表达谱芯片比较了多株常规和大分割放疗抗拒细胞后发现，PI3K/AKT/mTOR信号通路的多个基因存在表达差异，拟进一步采用Q-PCR、免疫印迹、RNAi、小动物PET等技术，在培养肿瘤细胞和荷瘤动物模型中研究PI3K/AKT/mTOR信号通路调控大分割放疗后肿瘤细胞DNA修复、糖代谢、增殖、死亡、乏氧微环境及分子机制；研究干预该信号通路影响NSCLC大分割放疗敏感性的可能；为放疗增敏及逆转放疗抗拒提供新靶点。同时获取NSCLC患者肿瘤组织进行裸鼠体内培养，与患者同步行大分割放疗，表达谱芯片检测信号通路相关基因变化，初步筛选预测大分割放疗敏感性的分子标记。