The Regulation of UPA and UPAR in Human Carcinoma Cells

UPA 和 UPAR 在人类癌细胞中的调控

基本信息

批准号：
7406565
负责人：
SHUANG HUANG
金额：
$ 23.25万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-12-01 至 2011-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7406565
关键词：
Affect Biological Cells Condition Development Doctor of Philosophy Elements Event Exhibits Funding Goals Half-Life Human In Vitro Indium Invasive Lead Link MAP Kinase Gene MAPK11 gene MAPK14 gene Malignant Epithelial Cell Malignant Neoplasms Mediating Messenger RNA Mitogen-Activated Protein Kinase Inhibitor Molecular Neoplasm Metastasis PLAUR gene Pathway interactions Phosphorylation Plasminogen Activator Play Protein Overexpression RNA Instability RNA-Binding Proteins Regulation Research Personnel Role SB 203580 Signal Transduction Small Interfering RNA Tumorigenicity Untranslated Regions Up-Regulation Urokinase Urokinase Plasminogen Activator Receptor Work base cancer cell cell growth design experience in vivo mRNA Decay mRNA Stability mRNA Transcript Degradation mutant neoplastic cell novel novel therapeutics p38 MAPK Signaling Pathway prevent programs rat Secp43 protein tumor growth tumor progression urokinase inhibitor

项目摘要

DESCRIPTION (provided by applicant): The overexpression of urokinase plasminogen activator (uPA) and its receptor (uPAR) is detected in various malignancies. Both in vitro and in vivo studies demonstrate that uPA/uPAR play an important role in tumor progression and metastasis. To define the mechanism responsible for high uPA/uPAR expression in invasive cancer cells, we previously showed that 1) the endogenous p38 MAPK activity is elevated in invasive cancer cells and is required for high uPA/uPAR expression; and 2) p38 MAPK maintains high uPA expression by promoting uPA mRNA stability. However, how p38 MAPK stabilizes uPA mRNA in invasive cancer cells remains unclear. In our preliminary studies, we identified an RNA-binding protein SECp43 that not only specifically interacts with p38a MAPK but also serves as a direct substrate of p38a MAPK in vitro. Overexpression of SECp43 destabilizes uPA mRNA while silencing SECp43 expression prolongs uPA mRNA half-life in p38 MAPK-inhibited condition, suggesting that SECp43 and p38a MAPK are functionally linked in regulating uPA mRNA stability. In further study, we found that SECp43 interacts with uPA mRNA stability in vivo and the region in uPA mRNA required for SECp43 interaction contains AU-rich element (ARE) motifs. Interestingly, we also found that cells with elevated p38 MAPK activity and uPA expression exhibit poor SECp43/uPA mRNA interaction and vice versa. These results suggest that p38a MAPK may stabilize uPA mRNA by impeding SECp43's ability to mediate uPA mRNA decay. This proposal seeks to capitalize on our previous work to 1) investigate how p38a MAPK regulates SECp43-mediated uPA mRNA decay; 2) determine the mechanisms involved in SECp43-mediated uPA mRNA turnover; and 3) determine how non-p38a-phosphorylable SECp43 affects tumor cell growth and metastasis. The proposed study should increase our understanding on p38 MAPK-mediated mRNA stabilization and mechanisms involved in elevated uPA/uPAR expression in invasive cancer cells. Also, gaining further understanding of the novel role of SECp43 in repressing uPA expression may lead to the development of a novel therapeutic approach to suppress tumor growth and metastasis.

描述（由申请人提供）：在多种恶性肿瘤中检测到尿激酶纤溶酶原激活剂（uPA）及其受体（uPAR）的过度表达。体外和体内研究均表明uPA/uPAR在肿瘤进展和转移中发挥重要作用。为了明确uPA/uPAR在侵袭性癌细胞中高表达的机制，我们之前表明：1）内源性p38 MAPK活性在侵袭性癌细胞中升高，并且是uPA/uPAR高表达所必需的； 2) p38 MAPK 通过促进 uPA mRNA 稳定性来维持高 uPA 表达。然而，p38 MAPK 如何稳定侵袭性癌细胞中的 uPA mRNA 仍不清楚。在我们的初步研究中，我们鉴定了一种RNA结合蛋白SECp43，它不仅与p38a MAPK特异性相互作用，而且在体外充当p38a MAPK的直接底物。 SECp43 的过度表达会破坏 uPA mRNA 的稳定性，而沉默 SECp43 的表达会延长 p38 MAPK 抑制条件下 uPA mRNA 的半衰期，这表明 SECp43 和 p38a MAPK 在调节 uPA mRNA 稳定性方面存在功能关联。在进一步的研究中，我们发现SECp43在体内与uPA mRNA稳定性相互作用，并且SECp43相互作用所需的uPA mRNA区域含有富含AU的元件（ARE）基序。有趣的是，我们还发现 p38 MAPK 活性和 uPA 表达升高的细胞表现出较差的 SECp43/uPA mRNA 相互作用，反之亦然。这些结果表明 p38a MAPK 可能通过阻止 SECp43 介导 uPA mRNA 衰减的能力来稳定 uPA mRNA。该提案旨在利用我们之前的工作来 1）研究 p38a MAPK 如何调节 SECp43 介导的 uPA mRNA 衰减； 2) 确定 SECp43 介导的 uPA mRNA 更新所涉及的机制； 3) 确定非 p38a-磷酸化 SECp43 如何影响肿瘤细胞生长和转移。拟议的研究应增加我们对 p38 MAPK 介导的 mRNA 稳定性以及侵袭性癌细胞中 uPA/uPAR 表达升高的机制的理解。此外，进一步了解 SECp43 在抑制 uPA 表达中的新作用可能会导致开发出抑制肿瘤生长和转移的新治疗方法。