外泌体lncRNA-HULC通过SDF-1/CXCR4轴促进结肠癌干细胞侵袭转移的功能与机制研究

Colon cancer stem cells (CCSCs) are the key causes being responsible for the invasion and metastasis of colon cancer, with the conduction of stromal-derived factor-1 (SDF-1) / CXC chemokine receptor (CXCR) axis. Epithelial mesenchymal transition (EMT) plays as the molecular basis of the formation and metastasis of CCSCs. Exosomes-derived long chain non-coding RNA (lncRNA) is a critical regulator of CCSCs EMT. We previously found that lncRNA-HULC (highly up-regulated in liver cancer) expression increased significantly in the exosomes of CCSCs with CXCR4+ phenotype. Exosomes-derived HULC could induce the EMT of CCSCs and was closely related to the metastasis of colon cancer. However, the regulation and the molecular mechanisms of exosomes-derived HULC in the organ targeting metastasis of CCSCs and the patients’ prognosis remain to be elucidated. Applying multi-techniques including flow cytometry, TaqMan Low Density Arrays, Bio-Plex Protein Suspension Array, and in vivo imaging in small animal, the present study aims to prove our scientific hypothesis in independent experiments on CCSCs, mice model and clinical colon cancer specimens, that HULC in CCSCs-derived exosomes induces EMT via miR-9 regulation and SDF-1/CXCR axial transduction, so as to promote the invasion and metastasis of CCSCs, and results in a poor prognosis of colon cancer patients. Meanwhile, the interacted cellular signaling pathways and the targeting downstream genes regulated by HULC in CCSCs will also be explored. The findings achieved from the present project are supposed to provide us with more theoretical basis and experimental evidences to improve the patients’ prognosis through a block of the invasion and metastasis of colon cancer, as we use the exosomes as a novel therapeutic vector.

结肠癌干细胞（CCSCs）是导致肿瘤转移的“元凶”，但需要SDF-1/CXCR4轴传导的参与。而上皮-间质转化（EMT）是CCSCs形成与转移的分子基础，长链非编码RNA（lncRNA）是重要的EMT调控因子。我们前期发现CXCR4+的CCSCs外泌体lncRNA-HULC表达显著升高，而HULC可诱导CCSCs的EMT。但CCSCs外泌体HULC是否与如何参与结肠癌的器官靶向性转移尚待阐明。本项目拟运用流式细胞术、低密度基因芯片、蛋白悬液芯片、小动物活体成像等技术，在细胞学、小鼠模型、临床样本三个层次，逐步验证CCSCs外泌体HULC通过调控miR-9，进而增强SDF-1/CXCR4轴传导，促进CCSCs的EMT和侵袭转移，导致结肠癌预后不良，及其细胞信号传导和下游调控靶基因相互作用的分子机理。为利用外泌体做为新型治疗载体，阻断结肠癌的复发转移，改善患者预后提供理论基础和科学证据。

结肠癌干细胞（CCSCs）是导致肿瘤转移的“元凶”，但需要SDF-1/CXCR4轴传导的参与。而上皮-间质转化（EMT）是CCSCs形成与转移的分子基础，长链非编码RNA（lncRNA）是重要的EMT调控因子。我们前期发现CXCR4+的CCSCs外泌体lncRNA-HULC表达显著升高，而HULC可诱导CCSCs的EMT。但CCSCs外泌体HULC是否与如何参与结肠癌的器官靶向性转移尚待阐明。. 该项目除应用常规医学实验技术，还综合灵活运用定量RT-PCR、 Western 杂交、免疫荧光、流式细胞术、激光共聚焦显微镜、PCR Array、小动物活体成像等多项先进科研手段，从CCSCs细胞、NOD/SCID小鼠活体模型和回顾性/前瞻性临床样本三个研究层次，逐步深入，相互验证：CCSCs外泌体HULC通过调控miR-9，及miR-9靶基因KRT80，进而增强SDF-1/CXCR4轴传导，促进CCSCs的EMT和对肝组织的“靶向集聚”，导致结肠癌的肝转移和患者的不良预后。. 本项目研究成果进一步明确了外泌体lncRNA-HULC通过诱导EMT，促进结肠癌侵袭转移，导致患者预后不良的分子机理。为利用外泌体做为新型治疗载体，阻断结肠癌的复发转移，改善患者预后提供了理论基础和科学证据。