生物钟基因ARNTL在急性白血病细胞铁死亡中的作用及机制研究

难治性和复发急性白血病生存率低，临床治疗面临挑战，阐明新的细胞死亡调控机制可为急性白血病的治疗带来新的希望。申请人已报道白血病耐药相关细胞自噬异常的分子机制，并初步发现一种新的选择性自噬通路，即Clockophagy通过降解生物钟核心蛋白ARNTL促进铁死亡。在此基础之上，本项目提出“自噬与ARNTL蛋白降解形成反馈环路促进脂质过氧化，从而导致铁死亡发生”的科学假说，并拟选用急性白血病细胞系、原代细胞及SCID小鼠为研究材料，采用CRISPR/Cas9基因编辑等研究手段，分别从整体、细胞和分子水平，重点研究：1)自噬通过促进ARNTL降解影响急性白血病细胞脂质过氧化的分子机制；2）ARNTL通过影响mTOR和/或HMGB1介导的自噬通路活化调控急性白血病细胞铁死亡的分子机制。本项目研究可望发现铁死亡的新调控机制，阐明生物钟基因的新功能，为白血病治疗药物的研发提供新思路。

Treatment for acute leukemia patients has improved, but challenges persist. Identifying new cell death mechanisms is important for overcoming drug resistance to improve chemotherapy. We have reported the molecular mechanism of autophagy abnormalities responsible for drug resistance in leukemia cells. We recently also show that Clockophagy, the selective degradation of the core circadian clock protein ARNTL by autophagy, is critical for ferroptosis. We further hypothesize that "autophagy and ARNTL protein degradation forms positive feedback to promote lipid peroxidation, resulting in ferroptosis." We will use acute leukemia cell lines, primary cells, SCID mice, as well as CRISPR/Cas9 gene editing technology to define 1) the molecular mechanism of autophagy-mediated ARNTL degradation in lipid peroxidation during ferroptosis; 2) the molecular mechanism of ARNTL in ferroptosis through affecting the activation of mTOR and HMGB1-dependent autophagy pathway. Thus, our findings will not only uncover a new pathway that facilitates ferroptosis induction through autophagic removal of the key circadian clock protein, but also provide a new approach for leukemia therapy.