MicroRNA 与自噬的“调控-反馈”机理参与肝癌转移的作用研究

Autophagy seems to function as a tumor protective mechanism against adverse environmental and cellular stresses (e.g., nutrient deprivation, hypoxia, and therapeutic stress) and cause formation of distant metastasis, underlining why tight control of this process is essential in order to prevent the development of pathological disorders. MicroRNAs have recently been well-characterized to modulate autophagy at different stages: induction, vesicle nucleation, vesicle elongation and retrieval, which is critical to maintain the autophagic activity and function. Interestingly, microRNA abundance and action may be under refined feedback regulation through selective autophagy that target microRNA-processing enzyme. In this study, based on the previous work, we will screen the specific microRNAs that modulate autophagy involved in the metastasis of hepatocellular carcinoma (HCC), and explore the effect of specific microRNAs on downstream target genes by functional analysis, in order to analyze the role of microRNAs on modulating autophagy and metastasis of HCC. Simultaneously, we will explore the feedback mechanism of autophagy and specific microRNA by exogenous alteration of the autophagic activity, in order to further reveal the interactive modulation of microRNA and autophagy involved in the metastasis of HCC. Ultimately, the molecular mechanism of "microRNA-autophagy-microRNA-downstream target genes-HCC metastasis" will be uncovered, and the new molecular markers and therapeutic targets of HCC will be discovered.

自噬是肿瘤抵抗营养缺乏、低氧、应激等不利环境，形成远处转移的重要因素之一，对其活性的精密调控至关重要。在自噬诱导、自噬囊泡形成、延伸、回纳过程中存在大量的microRNA调控，其调控网络是维系自噬活性及功能的关键。而自噬通过选择性降解microRNA合成酶参与microRNA合成过程，可能对microRNA 饱和度及活性形成反馈调控。本课题拟在前期工作基础上运用生物信息学技术筛选出在肝癌转移中调控自噬的特异性microRNA，并应用功能分析探索特异性microRNA对靶基因下游功能的影响，分析其在肝癌自噬、转移中的调控作用。同时通过外源性调节肝癌自噬活性，探索自噬对特异性microRNA的反馈机理，进一步揭示microRNA与自噬交互调控在肝癌转移中作用，明确"microRNA-自噬-microRNA-下游靶基因-肝癌细胞转移"的分子机制，为寻找肝癌转移新的分子预测标记和治疗靶点打下基础。

自噬是肿瘤抵抗营养缺乏、低氧、应激等不利环境，形成远处转移的重要因素之一，对其活性的精密调控至关重要。在自噬诱导、自噬囊泡形成、延伸、回纳过程中存在大量的microRNA调控，其调控网络是维系自噬活性及功能的关键。而自噬通过选择性降解microRNA合成酶参与microRNA合成过程，可能对microRNA 饱和度及活性形成反馈调控。本项目借助生物信息学、临床样本、实验研究，①初步筛选出miR-30a作为肝癌自噬及转移相关的关键microRNA，并证实miR-30a在肝癌细胞中表达下调调控肝癌细胞自噬蛋白Atg5及Beclin1表达升高，导致细胞自噬活性增强，提升细胞抵抗失巢凋亡能力，最终促进肝癌细胞转移；②探索发现合成酶蛋白DICER1在肝癌细胞“microRNA-自噬-microRNA”的调控反馈机制中起作用；③ miR-30a下调与肝癌自噬及微血管转移相关联，导致肝癌患者术后的复发转移，进一步提示并验证了自噬活性调控及反馈可能在肝癌治疗及预防复发转移中具有潜在的价值。本项目发表标注资助的第一或通讯作者论文7篇，其中SCI论文4篇，获国家发明专利1项，在此基础上获国家和省部级奖励3项，参加国家科技重大专项1项，协助培养博士后1名，博士生2名，科技骨干1名，正在积极申报上海市科研成果1项。