Proteasome inhibitors for the treatment of solid tumors

用于治疗实体瘤的蛋白酶体抑制剂

基本信息

批准号：
9753737
负责人：
Alexei Kisselev
金额：
$ 34.55万
依托单位：
AUBURN UNIVERSITY AT AUBURN
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-20 至 2022-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9753737
关键词：
Active Sites Age of Onset American American Cancer Society Animal Model Apoptosis Apoptotic BCL2 gene Bortezomib Breast Cancer Cell Breast Cancer Model Cancer Etiology Cardiotoxicity Cells Cessation of life Clinical Clinical Trials Clustered Regularly Interspaced Short Palindromic Repeats Cytotoxic Chemotherapy Diagnosis Disease Dose Drug Targeting Engineering Enzymes Epidermal Growth Factor Receptor Estrogen Receptors Estrogens FDA approved Family member Future Gene Expression Genes Hematology Human In Vitro MCL1 gene Malignant Neoplasms Mediating Multiple Myeloma Mus Mutation Neoplasm Metastasis Non-Malignant Normal tissue morphology Organ Oxidative Stress PMAIP1 gene Patients Play Progesterone Progesterone Receptors Proteasome Inhibition Proteasome Inhibitor Proteins Reactive Oxygen Species Recovery Relapse Resistance Site Solid Neoplasm Therapeutic Time Tissues Toxic effect Transcriptional Activation Woman Work Xenograft procedure addiction analog anticancer activity clinical efficacy clinically relevant experimental study improved in vivo inhibitor/antagonist malignant breast neoplasm molecular targeted therapies multicatalytic endopeptidase complex neoplastic cell novel overexpression pro-apoptotic protein receptor response tissue culture transcription factor triple-negative invasive breast carcinoma tumor

项目摘要

The proteasome inhibitors bortezomib (Btz), carfilzomib (Cfz) and ixazomib (Ixz) are successfully used for the treatment of multiple myeloma (MM), but lack clinical efficacy against solid tumors despite demonstrating significant activity in tissue culture and animal models. In an effort to understand this discrepancy, we decided to focus on triple-negative breast cancers (TNBC), a genetically diverse group that lacks targeted treatments. TNBCs overexpress pro-apoptotic protein NOXA, which plays a key role in proteasome inhibitor-induced apoptosis, and are proteasome-addicted. The proteasome has three pairs of active sites: ß5, ß1, and ß2. The primary target of Btz and Cfz are the ß5 sites. At concentrations of Btz and Cfz that induce apoptosis in TNBC in culture, co-inhibition of either ß1 or ß2 is also observed. These concentrations exceed clinically relevant concentrations, potentially explaining why proteasome inhibitors have no in vivo activity in solid tumors, and suggesting that stronger co-inhibition of either ß1 or ß2 would improve in vivo activity. It is not known whether the ß2 or the ß1 site is a better target. We developed specific inhibitors of the ß1 and ß2 sites and CRISPR- generated mutations of these sites. We found that LU-102 and mutations in the ß2 sites are much stronger sensitizers of TNBC cells to Cfz and Btz than the ß1 inhibitor NC-021 or ß1 mutations; ß2 mutations sensitize orthotopic xenografts of TNBC cells to sub-toxic doses of Cfz. LU-102 and ß2 mutations block recovery of proteasome activity in Cfz-treated cells. In contrast to myeloma cells, proteasome activity recovers in TNBC cells treated with clinically relevant concentrations of Cfz. We found that LU-102 and ß2 mutations inhibit recovery of proteasome activity by causing aggregation of Nrf1 (NFE2L1/TCF11), a transcription factor that up- regulates proteasome genes expression in cells treated with ß5 inhibitors. NC-021 and ß1 mutations do not block recovery of proteasome activity. Therefore, we hypothesize that ß2 inhibitors will sensitize TNBCs to FDA-approved ß5 inhibitors, by the mechanism which involves tumor-specific inhibition of Nrf1-mediated recovery of proteasome activity. We further hypothesize that targeting enzymes involved in Nrf1 activation will also sensitize TNBC to proteasome inhibitors. The specific aims of this proposal are: (i) to determine whether ß2 inhibitors sensitize TNBC to Cfz, Btz, and Ixz in vivo; (ii) to determine whether ß2 inhibitors block recovery of proteasome activity in a tumor-specific fashion in vivo and determine whether alternative approaches to target this recovery sensitize tumors to FDA-approved inhibitors. Accomplishing these aims will demonstrate that the ß2 sites and Nrf1 are effective drug targets in TNBC, establish the mechanism of action of ß2 inhibitors, pave the road to clinical trials of ß2 inhibitors in TNBC, and launch future work in solid tumors of different organs.

蛋白酶体抑制剂硼替佐米 (Btz)、卡非佐米 (Cfz) 和伊沙佐米 (Ixz) 已成功用于治疗多发性骨髓瘤（MM），但缺乏针对实体瘤的临床疗效，尽管已证明为了理解这种差异，我们决定在组织培养和动物模型中进行重大活动。重点关注三阴性乳腺癌（TNBC），这是一个缺乏针对性治疗的遗传多样性群体。 TNBC 过度表达促凋亡蛋白 NOXA，该蛋白在蛋白酶体抑制剂诱导的细胞凋亡中发挥关键作用蛋白酶体具有三对活性位点：ß5、ß1 和 ß2。 Btz 和 Cfz 的主要靶标是 ß5 位点，在 Btz 和 Cfz 浓度下可诱导 TNBC 细胞凋亡。在培养物中，还观察到 ß1 或 ß2 的共同抑制，这些浓度与临床高度相关。浓度，可能解释为什么蛋白酶体抑制剂在实体瘤中没有体内活性，以及这表明对 ß1 或 ß2 进行更强的共同抑制是否会提高体内活性尚不清楚。 ß2 或 ß1 位点是更好的靶标，我们开发了 ß1 和 ß2 位点以及 CRISPR-的特异性抑制剂。我们发现 LU-102 和 ß2 位点的突变更强 TNBC 细胞对 Cfz 和 Btz 的敏感性高于 ß1 抑制剂 NC-021 或 ß1 突变的敏感性； TNBC 细胞的原位异种移植物亚毒性剂量的 Cfz 和 ß2 突变会阻止恢复。 Cfz 处理的细胞中的蛋白酶体活性与骨髓瘤细胞相反，TNBC 中的蛋白酶体活性恢复。用临床相关浓度的 Cfz 处理的细胞我们发现 LU-102 和 ß2 突变会抑制。通过引起 Nrf1 (NFE2L1/TCF11) 聚集来恢复蛋白酶体活性，Nrf1 是一种转录因子，可增强调节用 ß5 抑制剂处理的细胞中的蛋白酶体基因表达，而 ß1 突变则不会。阻止蛋白酶体活性的恢复因此，我们认为 ß2 抑制剂会使 TNBC 敏感。 FDA 批准的 ß5 抑制剂，其机制涉及 Nrf1 介导的肿瘤特异性抑制我们进一步研究了参与 Nrf1 激活的靶向酶。还使 TNBC 对蛋白酶体抑制剂敏感。该提案的具体目的是：（i）确定是否。 ß2 抑制剂使 TNBC 在体内对 Cfz、Btz 和 Ixz 敏感；(ii) 以确定 ß2 抑制剂是否会阻碍恢复；体内以肿瘤特异性方式检测蛋白酶体活性，并确定是否有替代方法以这种恢复为目标，使肿瘤对 FDA 批准的抑制剂敏感。证明ß2位点和Nrf1是TNBC中有效的药物靶点，建立ß2的作用机制抑制剂，为 TNBC 中 ß2 抑制剂的临床试验铺平道路，并启动实体瘤的未来工作不同的器官。