胰腺癌细胞通过微囊泡（MV）运载miR-24调控淋巴管内皮细胞生长的机制研究

Some miRNA, released from the micro vesicles (MV) and highly expressed in tumor cells, can regulate the function of several genes. This kind of regulatory mechanism plays an important role in pancreatic cancer development. Lymphangiogenesis is also critical for pancreatic cancer to develop and metastasize in early stage. However, the regulation between miRNA and Lymphangiogenesis is still unclear. Our previous work found that miR-24 was highly expressed in the serum from patients with and pancreatic cancer, which was related to poor prognosis. We isolated the miR-24 from MV and confirmed the enrichment of miR-24 in the serum from pancreatic cancer patients. The same time, we isolated the miRNA-24 from the supernatant of human pancreatic cancer cells culture. We also saw the enrichment of miRNA-24 and it can regulate the lymphatic endothelium. Using the bioinformatics method, we predicted that the target gene of miRNA-24 was proapoptosis gene BCL2L11/BIM. Base on the previous work, we want to establish the non-contact coculture system and animal models between pancreatic cancer cells and Lymphatic endothelium, to verify whether pancreatic cancer cells can regulate the expression of BCL2L11/BIM by transporting miR-24 through MV, consequentially leading to the Lymphangiogenesis. Therefore, we can better understand the molecular mechanism of MV transportation between pancreatic cancer cells and Lymphatic endothelium. The expected result not only has great help for people to under the growth mechanism of pancreatic cancer Lymphatics but also offers a new way for the therapy of pancreatic cancer with target non-coding RNA as well.

一些miRNAs在肿瘤中高表达且被微囊泡（MV）包裹运输从而调控某些基因功能，该机制在胰腺癌发展过程中起着重要作用，而淋巴管生成在胰腺癌早期进展及远处转移过程中担当着重要角色，但二者的相互作用关系尚未阐明。我们前期工作发现胰腺癌病人血清中miR-24显著高表达与预后不良相关，并在血清中分离出MV发现其中miR-24富集，后在胰腺癌细胞培养上清分离的MV中也证实了miR-24富集，通过生物信息学预测其作用靶点是促凋亡基因BCL2L11，同时也观察到该MV对淋巴管内皮细胞生长有影响。本课题拟通过胰腺癌-淋巴管内皮细胞非接触式共培养体系及动物实验评价胰腺癌细胞能否通过MV运载miR-24调控淋巴管内皮细胞生长进而影响淋巴管形成，探讨微囊泡介导胰腺癌细胞和淋巴管内皮细胞之间相互作用的分子机制，本课题的实施不仅对揭示胰腺癌的淋巴管生长机制有着重要意义，更为拓展非编码RNA治疗胰腺癌的策略提供新策略。

miRNAs在肿瘤中高表达从而调控某些基因功能，很多研究揭示了其在胰腺癌发展过程中起着重要作用，胰腺癌极易进展及远处转移，阐明其中可能的机制对于改善胰腺癌的治疗现状有着重要意义。本课题围绕这一问题展开研究，通过验证miR-24与其靶基因BCL2L11/BIM之间的相关调控关系，进而观察到一系列生物学现象。研究证明了二者具有直接的靶点关系。首先发现在胰腺癌及相应细胞系中miR-24呈高表达，相应的BIM蛋白呈低表达，进一步通过荧光素酶实验证实了二者的直接调控关系。这一靶向调控不仅能够促进癌细胞的生长而且能促进血管细胞的增殖，从而加速了血管成环的趋势。进一步在裸鼠植瘤模型中也观察到了miR-24通过对BIM蛋白表达的抑制促进肿瘤细胞的生长及血管形成的现象。通过这一系列研究结果揭示了一条胰腺癌发生转移的新调控通路，即miR-24-Bim调控轴，并且有望成为潜在的胰腺癌治疗的靶点。