成骨细胞特异因子-2诱导肾癌上皮间质转化的作用及机制研究

Osteoblast specific factor-2 also named periostin(PN)was overexpressed in various human cancers. Our early study indicated that PN was overexpressed in renal carcinoma and the overexpression of PN correlated with the degree of malignancy and the poor prognosis of renal carcinoma. The mechanism of PN promoting invasion and metastasis of cancer is always related with inducing EMT of cancer cells, and,many signal pathways such as PI3K/AKt may be involved in the process of EMT. Our preliminary experiment confirmed that the phosphorylation level of Akt was up-regulated in the renal carcinoma issues of overexpressed PN. Sliencing the expression of PN in renal carcinoma cells could down-regulate the expression of EMT biomarkers and the phosphorylation level of Akt. So, we presumed that PN could promote invasion and metastasis of renal carcinoma by inducing EMT of cancer cells via PI3K/AKt signal pathway. The effect of PN on biological behaviour and EMT of renal carcinoma in vitro and in vivo will be studied by bilateral regulating the expression of PN in renal carcinoma cells in this project. Additionally, the mechanism of PN will be studied by interfering PI3K/AKt signal pathway. The project not only conduces to understand the effect and mechanism of PN on renal carcinoma, but also establish the foundation for PN as a promising target of intervention for renal carcinoma.

成骨细胞特异因子-2又被称为Periostin(PN)，其在多种恶性肿瘤中存在高表达。我们前期研究发现PN在肾癌组织中也存在高表达而且PN的高表达与肾癌的恶性程度和预后不良密切相关。PN促进肿瘤的侵袭和转移的机制通常与诱导肿瘤的上皮间质转化(EMT)有关，其过程涉及PI3K/AKt等多条信号通路的改变。我们通过预实验发现在高表达PN的肾癌组织中AKt的磷酸化水平明显升高。进一步沉默肾癌细胞PN的表达能够明显下调EMT标记物的表达及AKt的磷酸化水平。因此我们认为PN可能通过激活PI3K/AKt通路诱导肿瘤细胞EMT从而促进了肾癌的侵袭和转移。本课题通过构建PN过表达质粒并应用shRNA双向调控肾癌细胞PN的表达观察对肾癌细胞体内外生物学行为及EMT的影响；通过干预PI3K/AKt通路进一步探讨PN的作用机制。本研究有利于明确PN 在肾癌中的作用及机制，为发现一个新的肾癌的干预靶点奠定基础。

本项目以Periostin为研究对象，根据预实验结果Periostin在肾癌组织中存在高表达而且与肾癌的恶性程度和预后不良相关提出课题假设认为Periostin可能通过激活 PI3K/AKt 通路诱导肿瘤细胞 EMT 从而促进了肾癌的侵袭和转移进而设计该课题，拟通过体内外实验，发现Periostin促进肾癌侵袭和转移的作用及相关机制，借此发现一个新的、潜在的肾癌生物标记物和干预靶点。在该项目实际完成中，以Periostin对肾癌的作用及机制研究作为研究核心，成功构建Periostin的过表达慢病毒载体和Periostin-shRNA的慢病毒载体并实现成功转染。另发现上调Periostin的表达能够增加MMP活性，而且Periostin发挥作用是通过整合素αVβ3和αVβ5介导了FAK/JNK通路所致。此外，发表项目资助编号核心论文1篇，SCI论文1篇，另SCI论文1篇处于审稿状态。本项目实验结果基本符合预期研究结果，通过该项目进一步明确了Periostin促进肾癌侵袭的作用，并明确了其作用机制，为我们下一步Periostin对肾癌的转移机制研究奠定基础。