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）：肿瘤细胞依赖于血管生成来生存、增殖和转移。头颈肿瘤血管高度丰富，具有侵袭性，并且经常发生局部转移。因此，破坏肿瘤血管网络可能有利于口腔癌患者的治疗。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，并且VEGF通过上调抗凋亡Bcl-2的表达来增强内皮细胞的存活。使用抗体（例如阿瓦斯汀）或其一种受体抑制剂（例如 PTK787）抑制 VEGF 信号传导，可选择性消融肿瘤血管并抑制肿瘤生长。这些结果表明 VEGF/Bcl-2 通路对于肿瘤血管系统的维持至关重要。基于结构的 30 个数据库搜索导致了一种新型 Bcl-2 小分子抑制剂 (TW-37) 的开发。 TW-37 在体外诱导肿瘤细胞凋亡，并在体内抑制前列腺肿瘤 (PC-3) 的生长。最近的实验表明，TW-37 还在体外诱导新生血管内皮细胞凋亡，但不诱导人真皮成纤维细胞或正常前列腺细胞凋亡。然而，尚不清楚用 TW-37 阻断 Bcl-2 的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 的治疗性抑制对肿瘤血管生成和肿瘤生长的影响。本申请的目的是评估TW-37对血管生成的影响，并评估其对口腔肿瘤微血管密度和生长的影响。我们计划通过研究TW-37诱导内皮细胞凋亡过程的机制及其对体外毛细血管出芽的影响来实现这些目标。 SCID 人类血管生成小鼠模型将用于评估 TW-37 对免疫缺陷小鼠发育的人类血管的影响。此外，我们将转染荧光素酶的口腔肿瘤细胞植入SCID小鼠体内，通过体内生物发光分析TW-37对肿瘤生长、侵袭和转移的影响。内皮细胞凋亡对 TW-37 抗肿瘤作用的影响将通过在 SCID 小鼠中产生由显性失活 Caspase-9（抵抗 TW-37 诱导的细胞凋亡）稳定转导的内皮细胞血管化的肿瘤，或通过植入小鼠来评估Bax 小鼠口腔肿瘤细胞。这里产生的知识将增强我们对 Bcl-2 在肿瘤新生血管内皮细胞中的作用的理解，并可能为 Bcl-2 作为分子靶点进一步开发治疗高度血管化肿瘤的药物提供支持。这项工作可能证明 Bcl-2 小分子抑制剂代表了一类新型药物，可诱导肿瘤细胞凋亡并具有抗血管生成作用，这两种药物具有不同但可能具有协同作用的抗肿瘤作用。