PUMA调控自噬的分子机制及其在结直肠癌中的功能研究

PUMA是一个关键的促凋亡因子和肿瘤抑制因子，但其与自噬的关系尚未被研究。我们前期的研究表明PUMA通过促进细胞凋亡介导了结直肠癌的治疗，并在此过程中率先发现PUMA具有抑制自噬的新功能，但分子机制尚不清楚。以结直肠癌细胞为模型，利用蛋白质谱结合免疫共沉淀技术，我们初步证明PUMA与ULK1存在潜在的相互作用，并可能以此影响ULK1对Beclin1的磷酸化激活，最终抑制自噬的发生。在此基础上，本项目将：（1）进一步确认PUMA对自噬的调控关系；（2）深入研究PUMA与自噬调控因子ULK1及Beclin1的相互作用和时空转位，以揭示PUMA调控自噬的分子机制；（3）探索自噬的发生对PUMA及凋亡的反馈调控，以阐明自噬与凋亡的关系；（4）在体内验证本项目获得的科学发现，并以自噬为靶点筛选出更有效的多种药物联合治疗的方式，为结直肠癌的临床治疗提供理论依据。

PUMA is a critical pro-apoptotic factor and tumor suppressor, however, the relation between PUMA and autophagy has not been studied. Our previous study found that PUMA mediates the therapy of colorectal cancer through promoting cell apoptosis. In this process, we firstly found a bran new function of PUMA, is inhibiting autophagy, whose molecular mechanism is still unclear. By utilizing the technique of Protein Mass Spectrometry and Co-Immunoprecipitation, we preliminarily demonstrate there is a potential interaction between PUMA and ULK1 in the colorectal cancer cell model, which may Influence the phosphorylating activation of Beclin1 by ULK1 and finally inhibit autophagy initiation. Based on these findings, this present project will focus on (1) further confirming the regulation of autophagy by PUMA; (2) intensively investigating the interaction and translocation of PUMA and autophagy regulators ULK1 and Beclin1, to illustrate the molecular mechanism of PUMA regulating autohpagy; (3) exploring the feedback regulation of autophagy on PUMA and apoptosis, to clarify the relation between autophagy and apoptosis; (4) verifying scientific findings of this project, and screening out more effective combinational therapy of multiple drugs by targeting autophagy, which provides theoretical basis for clinical therapy of colorectal cancer.