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，是治疗癌症的重要治疗靶点。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结合转录因子，可与TGFb/Smad转录调节剂家族相互作用，刺激细胞增殖和肿瘤进展。RUNX2还抑制周期蛋白依赖性激酶抑制剂p21Cip1的启动子，抑制p21Cip1蛋白的表达，减少tgfb介导的内皮细胞生长抑制。我们假设RUNX2通过抑制TGFb1/Smad通路和抑制p21Cip1表达来促进细胞周期进程，从而刺激血管生成和内皮细胞增殖。以下具体目标将检验这一假设。特异性目的1：确定RUNX2在体内刺激内皮细胞增殖和促进血管生成中的作用。目的2：确定RUNX2的表达和磷酸化在控制内皮细胞周期进程和血管生成中的要求。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。本提案的目标是确定RUNX2如何增加内皮细胞增殖，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信号传导成分的相互作用。将采用几种分子方法，包括sirna介导的RUNX2敲低，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肿瘤内调节血管形成的新机制，并可能导致鉴定新的抗肿瘤药物或改善药物给药。因此，开发抑制EC增殖的抗血管生成治疗剂与NIH改善公众健康的使命高度相关，并且是可能在癌症治疗中变得重要的关键方法。虽然不是本提案的主题，但本研究中发现的策略和治疗方法也可能与其他依赖血管生成并引起重大健康问题的疾病的治疗相关。

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.