COBRA-1: A Novel Tubulin Depolymerizing Anticancer Agent

COBRA-1：一种新型微管蛋白解聚抗癌剂

• 批准号: 6644549
• 负责人: ALEXEI VASSILEV
• 金额: $ 10万
• 依托单位: PARADIGM PHARMACEUTICALS, LLC
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6644549
• 关键词: SCID mouse; antineoplastics; apoptosis; astrocytoma; binding sites; biological signal transduction; biotherapeutic agent; blood chemistry; breast neoplasms; chemical synthesis; cytotoxicity; dosage; drug design /synthesis /production; histopathology; paclitaxel; polymerization; tubulin

DESCRIPTION (provided by applicant): Microtubules, which are formed by the self-association of the alpha/beta-tubulin heterodimers, provide structural support for a cell and play key roles in cell motility, mitosis, and meiosis. They are also the targets of several anticancer agents, indicating their importance in maintaining cell viability. Currently available tubulin binding anticancer drugs, including new taxol derivatives and epothilones, interact with beta-tubulin subunit of the alpha/beta-tubulin heterodimers and have no effect on microtubule minus ends. Furthermore, cancer cells with an altered beta-tubulin expression profile may be resistant to these agents. We used a three-dimensional computer model of tubulin constructed based upon its recently resolved electron crystallographic structure for rational design of a novel mono-tetrahydrofuran (THF)-containing synthetic anticancer drug targeting a unique narrow binding cavity on the surface of alpha-tubulin. We discovered a previously unidentified region with a remarkable abundance of leucine residues, which is located between the GDP/GTP binding site and the taxol binding site. This unique region contains a narrow cavity with elongated dimensions, which could accommodate a fully stretched aliphatic chain with a length of up to twelve carbon atoms. Using this model, a comprehensive structure search of the organic compound files in the Parker Hughes Institute Drug Discovery Program led to the identification of the recently reported chiral THF-epoxides as potential molecular templates for the rational synthesis of novel anti-cancer drugs containing structural elements capable of hydrophobic binding interactions with this leucine-rich binding cavity of tubulin. Our lead compound designated as COBRA-1, inhibited GTP-induced tubulin polymerization in cell free turbidity assays. Treatment of human breast cancer and brain tumor (glioblastoma) cells with COBRA-1 caused destruction of microtubule organization and apoptosis. Like other microtubule-interfering agents, COBRA-1 activated the pro-apoptotic c-Jun N-terminal kinase (JNK) signal transduction pathway, as evidenced by rapid induction of c-jun expression. The further development of COBRA-1 as an anticancer agent will depend on in vivo efficacy, and toxicity studies in relevant animal models. We are now proposing to use the severe combined immunodeficiency (SCID) mouse model for detailed in vivo anticancer activity in SCID mice challenged with human breast cancer or glioblastoma cells. Our specific aims are: (i) To study the in vivo toxicity profile of COBRA-1 in BALB/c mice and (ii) To study the in vivo anti-cancer activity of COBRA-1 in a SCID mouse model of metastatic human breast cancer and glioblastoma. The knowledge gained from these studies described under Specific Aims 1-2 is expected to facilitate the design of innovative treatment regimens employing COBRA-1 for the treatment of metastatic solid tumors.

描述（由申请人提供）：微管由α/β-微管蛋白异二聚体的自我关联形成，为细胞提供了结构支持，并在细胞运动，有丝分裂和减数分裂中起关键作用。它们也是几种抗癌剂的靶标，表明它们在维持细胞活力方面的重要性。当前可用的微管蛋白结合抗癌药物，包括新的紫杉醇衍生物和雌酮，与α/β-微管蛋白异二聚体的β-微管蛋白亚基相互作用，对微管负端没有影响。此外，β-微管蛋白表达谱改变的癌细胞可能对这些药物具有抗性。我们使用了基于其最近分辨的电子晶体结构构建的三维计算机模型，用于用于新型单四氢呋喃（THF）的合理设计 - 含有合成的抗癌药物，旨在靶向alpha-bubulin表面上独特的狭窄结合腔。我们发现了一个以前未识别的区域，具有显着的亮氨酸残基，该区域位于GDP/GTP结合位点和紫杉醇结合位点之间。这个独特的区域包含一个带有细长尺寸的狭窄空腔，可以容纳一个完全拉伸的脂肪族链，其长度长达12个碳原子。使用该模型，对Parker Hughes Institute药物发现计划中有机化合物文件的全面结构搜索导致鉴定最近报道的手性THF-Epoxide是一种潜在的分子模板，用于合理合成新型抗癌药物，其中含有含水的结构元素，能够与这种富含Leucine-fibich结合的结构元素相互作用。我们指定为眼镜蛇1的铅化合物抑制了无细胞浊度测定中GTP诱导的小管蛋白聚合。用眼镜蛇1治疗人乳腺癌和脑肿瘤（胶质母细胞瘤）细胞会导致微管组织和凋亡的破坏。与其他微管裂化剂一样，Cobra-1激活了凋亡的C-JUN N末端激酶（JNK）信号转导途径，这是通过快速诱导C-JUN表达的诱导证明的。 Cobra-1作为抗癌剂的进一步发展将取决于体内功效，以及在相关动物模型中的毒性研究。我们现在建议使用严重的联合免疫缺陷（SCID）小鼠模型，以详细介绍对人类乳腺癌或胶质母细胞瘤细胞质疑的SCID小鼠的体内抗癌活性。我们的具体目的是：（i）研究Cobra-1在BALB/C小鼠和（ii）中的体内毒性特征，以研究Cobra-1在SCID小鼠的人体乳腺癌和胶质母细胞瘤的SCID小鼠模型中的体内抗癌活性。从特定目标1-2中描述的这些研究中获得的知识有望促进使用COBRA-1进行转移实体瘤治疗的创新治疗方案的设计。