Novel Transcriptional Regulators of Angiogenesis

描述(申请人提供)：血管生成促进肿瘤生长和转移，是癌症治疗的重要治疗靶点。血管生成因子激活控制内皮细胞增殖的转录因子。Runx2是一种DNA结合的转录因子，它与TGFb/Smad转录调节因子家族相互作用，刺激细胞增殖和肿瘤进展。Runx2还抑制细胞周期蛋白依赖性激酶抑制因子p21Cip1的启动子，抑制p21Cip1蛋白的表达，并减轻TGFb介导的内皮细胞生长抑制。我们推测RUNX2通过抑制TGFb1/Smad通路和抑制p21Cip1的表达促进细胞周期进程，从而刺激血管生成和内皮细胞的增殖。以下具体目标将检验这一假设。特异性目的1：建立RUNX2在体内刺激内皮细胞增殖和促进血管生成的作用。特异性目的2：明确RUNX2表达和磷酸化在调控内皮细胞周期进展和血管生成中的需求。特异性目的3：确定RUNX2如何通过抑制TGFb1/Smad通路和/或cdk抑制剂p21Cip1促进细胞周期进程和EC增殖。该方案的目的是确定RUNX2如何促进内皮细胞的增殖，确定RUNX2如何调节细胞周期进程，并确定RUNX2与调节p21Cip1表达的Smad信号组件的相互作用。将采用几种分子方法，包括siRNA介导的RUNX2的敲除，使用RUNX2诱导的细胞系，以及RUNX2的细胞周期调节活性。血管生成研究可能揭示调节肿瘤内血管形成的新机制，并可能导致识别新的抗肿瘤药物或改善对肿瘤的药物输送。因此，开发抑制EC增殖的抗血管生成治疗药物与NIH改善公共健康的使命高度相关，是可能成为癌症治疗的重要途径。虽然不是这项建议的主题，但这项研究中发现的策略和治疗方法可能也适用于其他依赖血管生成并导致重大健康问题的疾病的治疗。

DESCRIPTION (provided by applicant): Angiogenesis promotes tumor growth and metastasis and is an important therapeutic target in the treatment of cancer. Angiogenesis factors activate transcription factors that control endothelial cell proliferation. RUNX2 is a DNA-binding transcription factor that interacts with the TGFb/Smad family of transcriptional modulators to stimulate cell proliferation and tumor progression. RUNX2 also represses the promoter of p21Cip1, a cyclin-dependent kinase inhibitor, inhibits p21Cip1 protein expression, and reduces TGFb-mediated growth inhibition of endothelial cells. We hypothesize that RUNX2 stimulates angiogenesis and endothelial cell proliferation by promoting cell cycle progression through its inhibition of the TGFb1/Smad pathway and repression of p21Cip1 expression. The following specific aims will test this hypothesis. SPECIFIC AIM 1: To establish a role for RUNX2 in stimulating endothelial cell proliferation and promoting angiogenesis in vivo. SPECIFIC AIM 2: To define the requirement for RUNX2 expression and phosphorylation in controlling endothelial cell cycle progression and angiogenesis. SPECIFIC AIM 3: To determine how RUNX2 promotes cell cycle progression and EC proliferation through inhibition of the TGFb1/Smad pathway and/or the cdk inhibitor, p21Cip1. The goals of this proposal are to define how RUNX2 increases endothelial cell proliferation, to determine how RUNX2 regulates cell cycle progression, and to define the interactions of RUNX2 with Smad signaling components, which regulate p21Cip1 expression. Several molecular approaches will be employed, including siRNA-mediated knockdown of RUNX2, the use of RUNX2-inducible cell lines, and cell cycle regulatory activities of RUNX2. Angiogenesis research may uncover new mechanisms regulating blood vessel formation within tumors and could lead to identification of novel anti-tumor agents or improved drug delivery to tumors. Therefore, the development of anti-angiogenic therapeutic agents that inhibit EC proliferation is highly relevant to the NIH mission to improve public health and is a critical approach that may become important in the treatment of cancer. Although not a topic of this proposal, the strategies and treatments discovered in this study may also be relevant for the treatment of other diseases that depend on angiogenesis and cause significant health problems.