hsa_circ_RPPH1 / hsa_circ_0003596 调控循环肿瘤干细胞间充质-上皮转化促进肝癌转移的机制研究

循环肿瘤干细胞是肿瘤转移的关键因素，其间质-上皮转化（MET）是肿瘤转移至特定靶器官的关键过程，机制尚不明确。circRNA与肿瘤细胞MET关系密切。我们前期研究发现，hsa_circ_RPPH1调控肝癌干细胞自我更新，肝癌干细胞体外发生MET时hsa_circ_0003596显著上调，这两种circRNA表达模式呈负相关。本研究拟以此为基础，在细胞和动物水平深入开展以下研究：1）利用功能获得与缺失实验，在细胞水平确定hsa_circ_RPPH1和hsa_circ_0003596在肝癌干细胞自我更新与MET中的调控作用和机制；2）利用肝癌小鼠模型结合RNA pull down等技术研究循环肿瘤干细胞在靶器官定植前后hsa_circ_RPPH1和hsa_circ_0003596调控机制及重要相关分子；3）利用定量PCR分析关键分子在临床肿瘤转移中的诊断作用。以期为肿瘤转移和治疗提供诊断依据。

Circulating cancer stem cells are the key factor of tumor recurrence and metastasis. The mesenchymal-to-epithelial transition(MET) is pivotal for metastasis of circulating cancer stem cells to specific target organs, which mechanism remains largely unclear. Previous studies have suggested there is a close relationship between circRNA and cell transformation. We found that hsa_circ_RPPH1 in hepatocellular carcinoma stem cells(CSCs) can affect its self-renewal, and hsa_circ_0003596 expression is abnormal during MET program in vitro. Moreover, the expression patterns of these two circRNAs are correlated negatively. In this study, we use hsa_circ_RPPH1 and hsa_circ_0003596 as an entry point to further study: 1) To determine the biological functions of hsa_circ_RPPH1 and hsa_circ_0003596 in CSCs self-renewal and MET occurrence using loss-of-function and gain-of-function experiments at the cellular level; 2) To elucidate the regulation mechanism of hsa_circ_RPPH1 and hsa_circ_0003596 in circulating cancer stem cells before and after transplanting target organs using the mouse models combined with RNA pull down and so on; 3) To analyze the diagnostic role of key molecules in clinical samples using real-time PCR. We aim to provide a molecular target for diagnosis and intervention of tumor metastasis.