自噬是进化上高度保守的溶酶体降解途径。我们的前期研究表明当肿瘤细胞受到营养缺乏和化疗药物等压力刺激时，巨自噬与分子伴侣介导的自噬（CMA）相继顺序而非同步被激活，以不同方式降解受损的细胞器和蛋白质等内容物，以实现物质的循环再利用，帮助细胞度过危机。由此我们推断，自噬（巨自噬和CMA）可能是肿瘤细胞对抗癌药物产生抗性及抗性维持的重要机制。本课题将绿色荧光蛋白（GFP）基因转入白血病K562细胞中建立能稳定表达GFP的K562-GFP细胞株，并通过ADM长期间歇性诱导建立具有稳定耐药性的K562-GFP/ADM细胞株，体内外动态观察不同耐药阶段细胞自噬活性的变化，并通过化学药物或慢病毒载体shRNAs沉默自噬相关基因改变细胞自噬水平，研究自噬活性与白血病细胞获得性耐药及其特性维持之间的关系及调控机制。探索通过抑制细胞自噬活性来逆转白血病耐药，在临床耐药性和复发性白血病治疗中发挥重要作用。

Autophagy is an evolutionarily conserved and lysosome dependent protein degradation pathway. Our previous study indicated that macroautophagy and CMA were activated sequentially instead of simultaneously in starvation or chemotherapy drug-induced cancer cells in which damaged or superfluous proteins and organelles were cleared in different ways, the aim is to realize the recycling of material and help cells to endure the current crisis. From which we can infer that macroautophagy and CMA may be highly correlated to the mechanism of tumor resistance to chemotherapy. In this projects, We will transfer the green fluorescent protein (GFP) gene into K562 cells and establish K562-GFP cell line which the GFP was persistently expressed. The GFP labeled leukemia cells will be induced by adriamycin to establish a stable drug-resistance cell line (K562-GFP/ADM), then, in vitro and in vivo, dynamically observe the change trend of autophagic activity in different stages of drug resistance. Furthermore, we will artificially change the autophagy level to investigate whether the autophagy is involved in the molecular mechanisms for acquired chemoresistance in leukemia cells. This study will be helpful for explore the therapy strategy of inverting drug resistance, it will plays an important role in clinical treatment of resistant and relapsed leukemia.chemoresistance in leukemia cells and its LSCs, and the number and other features of LSCs. This study will be helpful for explore the therapy strategy of inverting drug resistance and eliminate LSCs, it will plays an important role in clinical treatment of resistant and relapsed leukemia.