调控自噬影响非小胞肺癌大分割放疗敏感性的机制研究

Hypofractionated radiotherapy plays an important role in patients with non small cell lung cancer (NSCLC). It is associated with excellent survival and local control rates, but some patients had local recurrence after hypofractionated radiotherapy. There is little knowledge with molecular mechanisms of hypofractionated radiation oncology in NSCLC. It is very important that we find some mechanisms overwhelming radiation resistance and improving the efficacy of hypofractionated radiotherapy. The molecular mechanisms of the PI3K / AKT / mTOR pathway affect radiosensitivity of NSCLC was already previous clarified. Preliminary experiments found that autophagy induced A549 and H1299 cell death by radiotherapy.We established the tumor cells models and nude mice xenograft models, and intend to discover the exact role of signaling pathway regulating autophagy (the Ras-Raf-MEK1/2-Erk1/2 and P53 signaling pathways)in NSCLC after hypofractionated radiotherapy, using the following methods, Q-PCR, Western blotting,immunofluorescence and RNA interference in our study. It is designed to show molecular mechanisms of DNA repair, cell proliferation and autophagy after hypofractionated radiotherapy. We regulate Ras-Raf-MEK1/2-Erk1/2 and P53 signaling pathways in order to provide a new target to improve the hypofractionated radiosensitivity and reverse resistance to hypofractionated radiotherapy.

大分割放疗是非小细胞肺癌（NSCLC）放疗手段之一，部分病人放疗后仍有复发。研究大分割放疗抗拒机制对NSCLC具有重要意义。自噬在NSCLC大分割放疗抗拒中作用尚未明确。我们前期研究了PI3K/AKT/mTOR通路影响NSCLC大分割放疗敏感性分子机制,同时发现自噬是大分割放疗诱导 A549与H1299 细胞死亡的主要方式。自噬可能是部分NSCLC大分割放疗抗拒的关键机制。本课题主要研究大分割放疗诱导不同类型细胞株NSCLC自噬变化，与自噬相关的信号通路（Ras-Raf-MEK1/2-Erk1/2通路和P53通路）关系。从细胞与整体水平采用Q-PCR、Western blotting与RNAi等，研究调控自噬相关通路大分割放疗后NSCLC细胞周期、自噬、细胞增殖mRNA与蛋白表达变化，探讨调控自噬通路提高NSCLC大分割放疗敏感的可行性，为NSCLC大分割放疗增敏与逆转放疗抗拒提供新思路。

大分割放疗是非小细胞肺癌（NSCLC）放疗手段之一，部分病人放疗后仍有复发。研究大分割放疗抗拒机制对NSCLC放疗具有重要意义。自噬在NSCLC大分割放疗抗拒中作用尚未明确。本研究探索了TIGAR基因在肺癌细胞中差异表达后对其放疗敏感性的影响及机制，并探讨了其临床意义。此部分实验探索是项目的基础，为进一步拓展及转化提供依据。研究首次发现下调TIGAR的表达，能够提高肺癌细胞放射治疗的敏感性，从而为改善临床肺癌患者放射治疗抵抗开辟方向。依据相关文献报道，TIGAR通过调控自噬影响细胞生存状态。实验进一步构建监控自噬流的EGFP-RFP-LC3质粒，构建稳定表达细胞系，进行深入的机制探索。探讨调控通路提高NSCLC大分割放疗敏感性可行性，为NSCLC大分割放疗增敏与逆转放疗抗拒提供新思路。