Melanoma Resistance to Apoptosis: Mechanisms and Therapeutic Potential

黑色素瘤对细胞凋亡的抵抗：机制和治疗潜力

基本信息

批准号：
8391110
负责人：
DAVID A. NORRIS
金额：
--
依托单位：
VA EASTERN COLORADO HEALTH CARE SYSTEM
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-10-01 至 2014-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8391110
关键词：
Apoptosis Apoptotic BCL2 gene Bortezomib Cells Characteristics Clinical Clinical Research Clinical Trials Collaborations Combined Modality Therapy Complex Disease Drug Combinations Drug Targeting Exhibits Family Future Human In Vitro Incidence Individual Lead Link MCL1 protein MG132 Malignant Neoplasms Mediator of activation protein Medical Medicine Melanoma Cell MicroRNAs Military Personnel Mission Modeling Molecular Oncologist Paclitaxel Patient Care Patients Pharmaceutical Preparations Population Pre-Clinical Model Proteasome Inhibitor Proteins RNA Interference Research Resistance Sampling Scientist Services Signal Transduction Skin Stem cells Sun Exposure Techniques Testing Therapeutic Treatment Efficacy United States Validation Xenograft Model Xenograft procedure base cancer stem cell cancer therapy chemotherapeutic agent clinical care cytotoxicity effective therapy experience in vivo in vivo Model inhibitor/antagonist killings melanoma member mimetics novel novel strategies novel therapeutic intervention outcome forecast research study response small molecule success temozolomide therapeutic target therapy resistant treatment strategy young woman

项目摘要

A fundamental characteristic of malignant melanoma is resistance to apoptosis, which largely determines melanoma's resistance to therapy. The complex interaction of pro-apoptotic and anti-apoptotic members of the Bcl-2 family is a central control point of apoptosis and a promising drug target. The BH3 mimetic ABT-737 is a potent small molecule inhibitor of the anti-apoptotic proteins Bcl-2/Bcl-XL/Bcl-w, and it exhibits promise for cancer treatment either as a single agent or in combination therapy. We have found that ABT-737 alone induced little cytotoxicity in melanoma cells, and knockdown experiments with RNAi techniques demonstrated that anti-apoptotic protein Mcl-1, but not Bcl-2 or Bcl-XL is the main mediator of melanoma resistance to ABT-737 treatment. In addition, ABT-737 displayed strong synergistic lethality when combined with either proteasome inhibitors (MG-132 or Bortezomib) or Paclitaxel, and mechanistic studies suggested that both proteasome inhibitors and Paclitaxel neutralize Mcl-1's functions. These exciting results indicate that drugs that neutralize Mcl-1 function are outstanding candidates for combination therapy with the ABT-737 for treating melanomas, and demand validation in preclinical models and further exploring the therapeutic potential of other drugs which target Mcl-1 in combination with ABT-737. It has also been proposed that cancer initiating cells (or cancer stem cells), which preferably initiate cancers, may be responsible for cancer resistance to therapy, and eliminating these cells may be essential for developing any cancer therapy with long term success. We will refer these cells as cancer imitating cells. We propose to investigate whether enriched melanoma initiating cells are more resistant to existing chemotherapeutic agents than non-sorted cells in melanoma, and to examine whether combinations of drugs that reduce multiple anti-apoptotic defenses such as ABT-737 plus Bortezomib or Paclitaxel will overcome this resistance of melanoma initiating cells. These studies will be an important component to understand whether melanoma initiating cells are more resistant to therapy. Specific Aim 1: To directly test the responses of enriched melanoma initiating cells to existing and new therapies in vitro. i) To determine whether enriched melanoma initiating cells are more resistant to conventional chemotherapeutic agents such as Temozolomide. ii) To determine whether combinations of ABT- 737 with either Bortezomib or Paclitaxel overcome the resistance in enriched melanoma initiating cells. Specific Aim 2: To verify the efficacy of the combinations of ABT-737 with either Bortezomib or Paclitaxel for treating melanoma using two novel xenotransplantation models: a model targeting human melanoma initiating cells in vivo, and a direct xenograft model for melanoma patient samples. Specific Aim 3: To investigate the therapeutic potential of combining BH3 mimetic ABT-737 with other compounds which inhibit Mcl-1. i) A new approach to down-regulating Mcl-1 in melanomas by microRNAs. ii) Other drugs known to inhibit Mcl-1. This project proposes to develop novel combination therapeutics by targeting multiple anti-apoptotic Bcl-2 members, and to verify the efficacy of the treatment combinations in killing melanomas, and most importantly, melanoma initiating cell populations. We believe that the studies proposed here will quickly lead to future clinical studies and to the clinical use of ABT-737 (or similar agents) in treating human melanoma patients. Importantly, this approach should not be restricted by different signaling signatures of individual melanomas. This proposal is a collaboration of experienced melanoma basic scientists, a skin stem cell expert, a melanoma oncologist, and an expert in xenotransplantation models of human cancers, and this team will make important advances in developing melanoma treatments based on reversing resistance to apoptosis.

恶性黑色素瘤的一个基本特征是对细胞凋亡的抵抗，这在很大程度上决定了黑色素瘤对治疗的抵抗力。促凋亡和抗凋亡成员的复杂相互作用 Bcl-2家族是细胞凋亡的中心控制点，也是一个有前途的药物靶点。 BH3 仿制品 ABT-737 是抗凋亡蛋白 Bcl-2/Bcl-XL/Bcl-w 的有效小分子抑制剂，它在作为单一药物或联合治疗的癌症治疗。我们发现单独使用 ABT-737 对黑色素瘤细胞几乎没有诱导细胞毒性，并且敲低实验 RNAi技术证明抗凋亡蛋白Mcl-1，而不是Bcl-2或Bcl-XL是主要的黑色素瘤对 ABT-737 治疗耐药的介质。此外，ABT-737表现出很强的协同作用与蛋白酶体抑制剂（MG-132 或硼替佐米）或紫杉醇联合使用时的致死率，以及机制研究表明蛋白酶体抑制剂和紫杉醇都会中和 Mcl-1 的功能。这些令人兴奋的结果表明，中和 Mcl-1 功能的药物是以下药物的杰出候选者：与 ABT-737 联合治疗黑色素瘤，并在临床前模型中进行需求验证并进一步探索其他靶向 Mcl-1 的药物与 ABT-737 联合的治疗潜力。还提出了优选引发癌症的癌症起始细胞（或癌症干细胞），可能是癌症对治疗产生耐药性的原因，消除这些细胞可能对于癌症治疗至关重要开发任何具有长期成功的癌症疗法。我们将这些细胞称为癌症模仿细胞。我们提议研究富集的黑色素瘤起始细胞是否对现有的具有更强的抵抗力化疗药物的效果优于黑色素瘤中未分选的细胞，并检查化疗药物的组合是否有效减少多重抗凋亡防御的药物，例如 ABT-737 加硼替佐米或紫杉醇，将克服黑色素瘤起始细胞的这种抵抗力。这些研究将成为重要组成部分了解黑色素瘤起始细胞是否对治疗更具抵抗力。具体目标 1：直接测试富集的黑色素瘤起始细胞对现有和黑色素瘤的反应。体外新疗法。 i) 确定富集的黑色素瘤起始细胞是否对常规化疗药物如替莫唑胺。 ii) 确定ABT-的组合是否第737章具体目标 2：验证 ABT-737 与硼替佐米或硼替佐米组合的功效使用两种新型异种移植模型治疗黑色素瘤的紫杉醇：针对人类的模型体内黑色素瘤起始细胞，以及黑色素瘤患者样本的直接异种移植模型。具体目标 3：研究 BH3 模拟 ABT-737 与其他药物相结合的治疗潜力抑制Mcl-1的化合物。 i) 一种通过 microRNA 下调黑色素瘤中 Mcl-1 的新方法。 ii) 已知可抑制 Mcl-1 的其他药物。该项目拟通过靶向多种抗凋亡 Bcl-2 来开发新型联合疗法成员，并验证治疗组合在杀死黑色素瘤方面的功效，最重要的是，黑色素瘤起始细胞群。我们相信这里提出的研究将很快导致未来临床研究以及 ABT-737（或类似药物）在治疗人类黑色素瘤患者中的临床应用。重要的是，这种方法不应受到个体不同信号特征的限制。黑色素瘤。该提案是经验丰富的黑色素瘤基础科学家、皮肤干细胞的合作成果专家、黑色素瘤肿瘤学家和人类癌症异种移植模型专家，以及这个团队将在开发基于逆转细胞凋亡抵抗的黑色素瘤治疗方面取得重要进展。