p53-lncRNA MIR17HG通路在胰腺癌侵袭转移中的功能和分子机制研究

Early metastasis is one of the key factors leading to the dismal prognosis of human pancreatic ductal adenocarcinoma (PDAC). Mutant p53 protein accumulation and sustained activation of its oncogenic signaling play an critical role in the metastatic cascade of PDAC. Recently, study of long non coding RNA (lnc RNA) has brought a new light of hope for cancer treatment. Our previous data demonstrated that lncRNA MIR17HG depicted a significant upregulation in human PDAC and presented a notably association with poor prognosis and p53 status. However, the potential function and mechanism of p53-regulated MIR17HG in PDAC metastasis remain unclear. In this study, we aim to systematically clarify the regulation of different p53 status on the MIR17HG expression in both tissue and cell levels, and explore the biological function of MIR17HG in PDAC metastasis in invitro and vivo. Besides, we further seek to screen and identify its binding protein complexes and key effect targets of MIR17HG by employing a series of experimental techniques, including RNA pull-down assay, protein mass spectrometry and RNA immunoprecipitation, etc. This study will probably identify the key targets either to restore the function of wildtype p53 or restrain the mutant p53 oncogenic signaling, thus promoting the personalized therapy based on multi-targets intervention strategy to ultimately improve the prognosis of pancreatic cancer.

早期转移是导致胰腺癌预后差的关键因素之一，而p53突变及相关信号通路的异常活化在胰腺癌转移过程中扮演了重要角色。近年来长链非编码RNA研究为肿瘤诊治带来了新的曙光，申请者前期工作显示，LncRNA MIR17HG在胰腺癌中表达明显上调，是患者预后不良的危险因素，且与p53状态呈现密切相关性，目前有关p53所调控的MIR17HG在胰腺癌侵袭转移中的功能和分子机制尚不清楚。本项目旨在组织和细胞水平系统研究不同状态p53对MIR17HG表达的调控作用，借助体外实验和动物模型全面探索MIR17HG在胰腺癌侵袭转移中的生物学功能，并综合利用RNA pull-down、蛋白质谱等实验技术解析和鉴定其相互作用蛋白质及下游功能靶基因，以期发现重塑野生型p53功能或抑制突变型p53通路的关键靶点，推动胰腺癌多靶标联合干预的个体化治疗，最终改善患者预后。

早期转移是导致胰腺癌预后差的关键因素之一，而p53突变及相关信号通路的异常活化在.胰腺癌转移过程中扮演了重要角色。近年来长链非编码RNA在胰腺癌发生发展中的作用备受关注。本项目在组织和细胞水平系统研究了不同状态p53对MIR17HG表达的调控作用，借助体外实验和动物模型全面探索MIR17HG在胰腺癌侵袭转移中的生物学功能，并综合利用转录组测序结合蛋白质谱等实验技术解析和鉴定其下游关键靶基因。结果发现：1）野生型p53对MIR17HG具有负性调控作用，而R273H突变型p53则能够正性调控MIR17HG表达；2）MIR17HG在胰腺癌中表达明显上调，且与神经侵犯、淋巴结转移、分期晚和生存期短显著相关；3）MIR17HG能够促进胰腺癌细胞侵袭迁移，抑制MIR17HG表达能够明显阻碍胰腺癌细胞体内外侵袭和转移；4）胰腺癌细胞中MIR17HG能够通过影响NBL1、DKK2、CAMK2B和DLX5等多种蛋白表达调控TGF-beta和Wnt等重要癌症相关信号通路促进细胞侵袭和迁移。以上结果表明MIR17HG及其下游NBL1通路在p53突变驱动胰腺癌侵袭转移过程中发挥重要作用，进一步深入研究MIR17HG调控NBL1表达的分子机制并研发相应小分子药物有望解决靶向p53突变药物的研发瓶颈，推动胰腺癌多靶标联合干预的个体化治疗，最终改善患者预后。