miR-126调节VEGF-MAPK/Akt信号通路对苦参碱衍生物抗鼻咽癌作用及其机制研究

Nasopharyngeal carcinoma is one of the most common head and neck malignant tumors in Guangxi . Studies have shown the regulatory role of miR - 126 -VEGF had an important role in occurrence and development of different types of tumors but its role in nasopharyngeal carcinoma has rarely been reported .Research from a new set of matrine derivatives, found the derivative YYJ18 has stronger effect in the inhibition of the growth of nasopharyngeal carcinoma cells than matrine, and found that the changes in ERK1/2, p38 and Akt signal pathway is related to this mechanism. For the further study of the role matrine and matrine derivatives, its target and differences in Nasopharyngeal carcinoma cells, through the introduction of exogenous miR - 126 in nasopharyngeal carcinoma cells, observe the regulatory role of miR - 126 in VEGF - MAPK/Akt pathways. At the same time, to discuss whether matrine and matrine derivatives by intervening in miR - 126 - VEGF regulation, affect the MAPK/Akt signal pathway, and induce apoptosis , inhibition of cell proliferation ,invasion and metastasis of nasopharyngeal carcinoma cells . This project will be conducted on mechanism of matrine derivatives, especially the study of target gene discovery and function to provide experimental basis.

鼻咽癌是广西区域性高发的头颈部恶性肿瘤之一。已有研究表明miR-126-VEGF的调控在多种肿瘤的发生、发展中起着重要的作用，但在鼻咽癌中鲜见报道。课题组从一系列新的苦参碱衍生物中，发现其中的衍生物YYJ18具有比苦参碱更强的抑制鼻咽癌细胞生长的作用，且发现其机制与ERK1/2、p38和Akt信号通路变化有关。为进一步研究苦参碱及苦参碱衍生物抗鼻咽癌细胞作用的靶点及其差异，通过在鼻咽癌细胞中引入外源性的miR-126，观察miR-126对VEGF-MAPK/Akt通路的调控作用；同时，探讨苦参碱及苦参碱衍生物是否通过干预miR-126-VEGF调控，影响下游MAPK/Akt信号通路，进而促进鼻咽癌细胞凋亡和抑制鼻咽癌细胞的增殖、侵袭转移。本项目为明确苦参碱衍生物具体作用机理，特别对靶基因发现及功能的研究提供实验依据。

在前期研究中我们通过对传统中草药苦参碱进行改构获得了具有更强特异性抑制鼻咽癌生长的苦参碱衍生物YYJ18，但尚未明确其抗鼻咽癌的机理。本次课题利用分子生物学及生物信息学相关实验技术，结合体内及体外全面系统的研究了YYJ18对鼻咽癌细胞的生物学影响，并通过引入外源性microRNA深入探讨了其中的分子调控机制。结果显示：（1）YYJ18可以抑制鼻咽癌细胞的增殖、转移及侵袭；（2）miR-146b-5p在鼻咽癌组织和鼻咽癌细胞中低表达，并且可受YYJ18的调控；（3）上调miR-146b-5p的表达水平可在体外抑制鼻咽癌细胞的增殖、转移及侵袭，并且能够逆转鼻咽癌细胞的上皮间质转化，在体内可以抑制鼻咽癌细胞的生长；（4）miR-146b-5p的直接靶基因为HNRNPD，并且主要通过失活PI3K/AKT信号通路发挥生物学作用；（5）YYJ18可通过提高miR-146b-5p的表达发挥抗鼻咽癌作用；（6）miR-126-3p在鼻咽癌组织和细胞系中表达上调，而沉默miR-126-3p可以抑制肿瘤细胞的增殖、侵袭和转移，提示miR-126-3p可能是鼻咽癌治疗的潜在靶标。通过本课题的研究，我们明确了YYJ18抗鼻咽癌的具体作用机理，发现了新的靶基因并完成了其相关的功能研究。