长链非编码RNA-PVT1促进浆液性卵巢癌恶性行为的作用和机制

Recent studies showed that fallopian tube (FT) secretory epithelia may be the primary cell origin and habor the precursors of ovarian low grade(LG-SOC) and high-grade serous ovarian carcinomas（HG-SOC）. In different from LGSOC, HGSOC are rapidly growing , highly aggressive and deadly form of disease. Although associated genetic mutations are different between LGSOC and HGSOC, the molecular mechanism for tumor behavior remain undetermined. The purpose of this study is to explore and characterize whether the long non-coding RNAs(lncRNAs) are contributed to the aggressive behavor of HG-SOC. To search for candidates of lncRNAs that are related to HGSOC, we performed LncRNA microarray analysis in HG-SOC and LG-SOC and fallopian tube (FT)as control. We identified and validated LncRNA- PVT1 as one of lncRNAs that was signficantly expressed in HG-SOC. Introducing PVT1 overexpression promotes ovarian cancer colony formation and cell invasion. Up regulation of vimentin and down regulation of E-cadherin was also detected in PVT1 overexpressed cells comared to control cells.All these preliminary findings prompt us to propose that PVT1 may play an important role in the tumorigenesis and metastasis of HG-SOC. To test our hypothesis, we will first determine the functional effect of PVT1 on tumorigenesis and metastasis of ovarian cancer in vitro and in vivo. Then, RNA pull-down and RIP will be used to identify the proteins that are physically associated with PVT1. And finally, we will examine the expressions of PVT1 and its associated molecules in HG-SOC patient samples to determine whether their expressions are correlated with tumor progression and overall survival. The ultimate goal of this study is to clarify and characterize the functional role of LncRNA-PVT1 in tumorigenesis and metastasis of high-grade serous ovarian carcinomas.

最近研究表明，输卵管是低级别和高级别浆液性卵巢癌（HG-SOC）的共同起源，但HG-SOC恶性程度更高、预后更差。对比分析两种浆液性癌，揭示HG-SOC恶性行为背后的分子机制是本课题目标。PVT1是我们前期应用lncRNA芯片筛选获得的在HG-SOC中特异高表达的长链非编码RNA，进一步预实验结果显示PVT1促进卵巢癌细胞的克隆形成和侵袭力，并诱导上皮-间质转化（EMT），但PVT1发挥作用的分子机制尚不明确。本课题拟通过干预表达，利用体外和体内实验明确其在HG-SOC中的生物学功能；进一步利用RNA pull-down、RIP结合质谱等方法筛选和鉴定PVT1特异性结合蛋白及下游关键分子；并利用原位杂交和免疫组化分析PVT1及相关分子与肿瘤发生发展和临床预后的相关性。研究将有助于揭示lncRNA参与高级别浆液性卵巢癌的发生发展机制，为该病的早期诊断和治疗提供新的分子靶点。

输卵管是低级别和高级别浆液性卵巢癌的共同起源，但是高级别浆液性癌恶性程度更高、预后更差，对比分析两种浆液性肿瘤，揭示高级别浆液性癌恶性行为背后的分子机制具有重要意义。我们前期对两种浆液性癌进行了lncRNA芯片分析，发现lncRNA-PVT1和HMGA1P6在高级别浆液性癌中表达上调。本课题主要围绕这两个长链非编码RNA及其相关的miRNA开展工作。 1. PVT1在高级别浆液性癌（HGSOC）组织中拷贝数增加，，PVT1高表达的患者预后较差。 PVT1可编码miR-1204,miR-1205, miR-1206, miR-1207四个miRNA，PVT1及其编码miRNA在HGSOC显著高表达， PVT1编码miRNAs促进卵巢癌细胞的增殖和侵袭力。2.HMGA1P6在HGSOC中高表达，并促进侵袭及EMT进程。重要的是，我们发现HMGA1P6通过ceRNA机制上调HMGA1和HMGA2的表达，HMGA1P6上游又受到HMGA1的转录激活，形成正反馈调控环路。在本基金的支持下，共发表SCI论文5篇（已标注），其中1篇发表在Cell Death & Differentiation（中科院1区，影响因子8.34），申请国家发明专利1项。