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）：微管是由α / β微管蛋白异源二聚体自结合形成的，为细胞提供结构支持，在细胞运动、有丝分裂和减数分裂中起关键作用。它们也是几种抗癌药物的靶标，表明它们在维持细胞活力方面的重要性。目前可用的微管结合抗癌药物，包括新的紫杉醇衍生物和艾泊霉素，与α / β -微管蛋白异源二聚体的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有耐药性。我们利用基于微管蛋白最近解析的电子晶体结构构建的微管蛋白三维计算机模型，针对α -微管蛋白表面独特的狭窄结合腔，合理设计了一种新型含单四氢呋喃（THF）的合成抗癌药物。我们在GDP/GTP结合位点和紫杉醇结合位点之间发现了一个以前未发现的亮氨酸残基丰富的区域。这个独特的区域包含一个狭长的空腔，它可以容纳一个长度高达12个碳原子的完全拉伸的脂肪链。利用该模型，帕克休斯研究所药物发现项目对有机化合物文件进行了全面的结构搜索，发现了最近报道的手性thf -环氧化物作为合理合成新型抗癌药物的潜在分子模板，这些药物含有能够与这种富含亮氨酸的小管蛋白结合腔进行疏水结合相互作用的结构元件。我们的先导化合物命名为COBRA-1，在无细胞浊度试验中抑制gtp诱导的微管蛋白聚合。用COBRA-1治疗人乳腺癌和脑肿瘤（胶质母细胞瘤）细胞可引起微管组织破坏和细胞凋亡。与其他微管干扰剂一样，COBRA-1激活促凋亡的c-Jun n -末端激酶（JNK）信号转导通路，快速诱导c-Jun表达。进一步开发COBRA-1作为抗癌药物将取决于体内疗效和相关动物模型的毒性研究。我们现在建议使用严重联合免疫缺陷（SCID）小鼠模型来详细研究受人乳腺癌或胶质母细胞瘤细胞攻击的SCID小鼠体内抗癌活性。我们的具体目的是：(i)研究COBRA-1在BALB/c小鼠体内的毒性谱；（ii）研究COBRA-1在转移性人乳腺癌和胶质母细胞瘤的SCID小鼠模型中的体内抗癌活性。在Specific Aims 1-2中描述的这些研究中获得的知识有望促进采用COBRA-1治疗转移性实体瘤的创新治疗方案的设计。