Novel Transcriptional Regulators of Angiogenesis

描述（由申请人提供）：血管生成促进肿瘤生长和转移，并且是癌症治疗中的重要治疗靶点。血管生成因子激活控制内皮细胞增殖的转录因子。RUNX 2是一种DNA结合转录因子，与TGF β/Smad家族的转录调节因子相互作用，刺激细胞增殖和肿瘤进展。RUNX 2还抑制p21 Cip 1（一种细胞周期蛋白依赖性激酶抑制剂）的启动子，抑制p21 Cip 1蛋白表达，并减少TGF β介导的内皮细胞生长抑制。我们推测RUNX 2通过抑制TGF β 1/Smad通路和抑制p21 Cip 1表达促进细胞周期进程，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。具体目的1：确定RUNX 2在体内刺激内皮细胞增殖和促进血管生成中的作用。具体目的2：确定RUNX 2表达和磷酸化在控制内皮细胞周期进程和血管生成中的需求。具体目标3：确定RUNX 2如何通过抑制TGFb 1/Smad通路和/或cdk抑制剂p21 Cip 1促进细胞周期进展和EC增殖。该提案的目标是确定RUNX 2如何增加内皮细胞增殖，确定RUNX 2如何调节细胞周期进程，并确定RUNX 2与Smad信号传导组分的相互作用，其调节p21 Cip 1表达。将采用几种分子方法，包括siRNA介导的RUNX 2敲低，RUNX 2诱导型细胞系的使用，以及RUNX 2的细胞周期调节活性。血管生成研究可能会发现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药物向肿瘤的输送。因此，抑制EC增殖的抗血管生成治疗剂的开发与NIH改善公众健康的使命高度相关，并且是在癌症治疗中可能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治疗依赖于血管生成并导致严重健康问题的其他疾病有关。

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.