Inhibition of Bcl-2 and Head & Neck Tumor Angiogenesis

Bcl-2 和 Head 的抑制

• 批准号: 7025077
• 负责人: Jacques Eduardo Nor
• 金额: $ 35.18万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7025077
• 关键词: BCL2 gene /protein; SCID mouse; angiogenesis; angiogenesis inhibitors; antineoplastics; apoptosis; drug screening /evaluation; gene induction /repression; head /neck neoplasm; human genetic material tag; neoplasm /cancer blood supply; neoplasm /cancer transplantation; neoplastic growth; nonhuman therapy evaluation; tissue /cell culture; vascular endothelium

DESCRIPTION (provided by applicant): Tumor cells depend on angiogenesis to survive, proliferate, and metastasize. Head & neck tumors are highly vascularized, invasive, and frequently develop local metastasis. Therefore, disruption of the tumor vascular network might be beneficial for treatment of patients with oral cancer. It is known that vascular endothelial growth factor (VEGF) is a strong inducer of tumor angiogenesis, and that VEGF enhances endothelial cell survival by upregulating the expression of the anti-apoptotic Bcl-2. Inhibition of VEGF signaling with an antibody (e.g. Avastin), or with an inhibitor of one its receptors (e.g. PTK787) results in selective ablation of tumor blood vessels and inhibition of tumor growth. These results demonstrate that the VEGF/Bcl-2 pathway is critical for the maintenance of tumor vasculature. Structure based 30-database searching led to the development of a novel small molecule inhibitor of Bcl-2 (TW-37). TW-37 induces apoptosis of tumor cells in vitro, and, inhibits growth of prostate tumors (PC-3) in vivo. Recent experiments demonstrated that TW-37 also induces apoptosis of neovascular endothelial cells in vitro, but not human dermal fibroblasts or normal prostate cells. However, it is not known if blockade of Bcl-2's function with TW-37 is sufficient to disrupt tumor blood vessels and to inhibit head & neck tumor growth. The broad long-term goals of this research are to understand the effect of therapeutic inhibition of Bcl-2 on tumor angiogenesis and tumor growth. The objectives of this application are to evaluate the effect of TW-37 on angiogenesis, and to evaluate its effect on the microvessel density and growth of oral tumors. We plan to accomplish these objectives by studying the mechanisms involved in the process of TW-37-induced endothelial cell apoptosis, and its effects on capillary sprouting in vitro. The SCID Mouse Model of Human Angiogenesis will be used to evaluate the effect of TW-37 in human blood vessels developed in immunodeficient mice. In addition, we will implant oral tumor cells transduced with Luciferase in SCID mice to analyze the effect of TW-37 on tumor growth, invasion, and metastasis by in vivo bioluminescence. The impact of endothelial cell apoptosis on TW-37's anti-tumor effect will be evaluated by generating tumors vascularized with endothelial cells stably transduced with dominant negative Caspase-9 (resistant to TW-37-induced apoptosis) in SCID mice, or by implanting murine oral tumor cells in Bax mice. The knowledge generated here will enhance our understanding about the role of Bcl-2 in neovascular endothelial cells of tumors, and may provide support for Bcl-2 as a molecular target for further development of drugs for treatment of highly vascularized tumors. This work may demonstrate that small molecule inhibitors of Bcl-2 represent a novel class of drugs that induce tumor cell apoptosis and are anti-angiogenic, two distinct and perhaps synergistic anti-tumor effects.

描述（由申请人提供）：肿瘤细胞取决于血管生成以生存，增殖和转移。头部和颈部肿瘤是高度血管化的，侵入性的，并且经常发展局部转移。因此，肿瘤血管网络的破坏可能有益于治疗口腔癌患者。众所周知，血管内皮生长因子（VEGF）是肿瘤血管生成的强诱导剂，VEGF通过上调抗凋亡Bcl-2的表达来增强内皮细胞的存活。用抗体（例如avastin）或一种受体的抑制剂（例如PTK787）抑制VEGF信号传导可导致肿瘤血管的选择性消融和抑制肿瘤生长。这些结果表明，VEGF/BCL-2途径对于维持肿瘤脉管系统至关重要。基于结构的30数据库搜索导致了BCl-2的新型小分子抑制剂的发展（TW-37）。 TW-37在体外诱导肿瘤细胞的凋亡，并在体内抑制前列腺肿瘤的生长（PC-3）。最近的实验表明，TW-37在体外还诱导了新生血管内皮细胞的凋亡，但没有人类真皮成纤维细胞或正常的前列腺细胞。但是，尚不清楚Bcl-2的TW-37功能是否足以破坏肿瘤血管并抑制头颈肿瘤的生长。这项研究的广泛长期目标是了解Bcl-2治疗性抑制对肿瘤血管生成和肿瘤生长的影响。本应用的目标是评估TW-37对血管生成的影响，并评估其对微血管密度和口腔肿瘤生长的影响。我们计划通过研究参与TW-37引起的内皮细胞凋亡过程的机制来实现这些目标，及其对体外毛细血管发芽的影响。人血管生成的SCID小鼠模型将用于评估TW-37在免疫缺陷小鼠中发育的人血管的影响。此外，我们还将在SCID小鼠中植入用荧光素酶转导的口腔肿瘤细胞，以分析TW-37对体内生物发光的肿瘤生长，侵袭和转移的影响。内皮细胞细胞凋亡对TW-37抗肿瘤作用的影响将通过产生肿瘤，该肿瘤用在SCID小鼠中稳定转导的内皮细胞稳定转导的内皮细胞（耐显式Caspase-9），或在bax小鼠中植入鼠口腔肿瘤细胞。此处产生的知识将增强我们对Bcl-2在肿瘤新血管内皮细胞中的作用的理解，并可能为Bcl-2提供支持，作为进一步开发药物以治疗高度血管化肿瘤的分子靶标。这项工作可能表明，Bcl-2的小分子抑制剂代表了诱导肿瘤细胞凋亡的一类新型药物，具有抗血管生成，两种抗血管生成，两种不同的，也许是协同的抗肿瘤作用。