CRM1 INHIBITORS SENSITIZE MULTIPLE MYELOMA CELLS TO TOPOISOMERASE II AND PROTEASOME INHIBITORS

 描述(申请人提供)：多发性骨髓瘤(MM)约占所有血液系统恶性肿瘤的10%，估计2014年美国的新病例和死亡人数分别为24,050人和11,090人。在过去的几年中，反应和存活率显著增加，这主要是由于高效免疫调节剂、蛋白酶体抑制剂的引入，以及大剂量化疗和自体干细胞移植的扩大使用。尽管取得了这些重大进展，多发性骨髓瘤仍然是一种不治之症，患者最终死于对抗骨髓瘤治疗无效的进展性疾病。显然需要更多有效的治疗方法。在……里面 在我们的实验室，我们已经证明了高密度的人MM细胞通过将Topo IIa从细胞核运输到细胞质而对DNA拓扑异构酶II(Topo II)抑制剂表现出从头开始的耐药性。我们已经证明，染色体维持区1(CRM1或XPO1)蛋白与Topo IIa的核输出信号(NES)结合，并且CRM1的敲除或其小分子的抑制导致Topo IIa的核滞留和MM细胞对Topo II抑制剂的重新敏感。KPT-330是一种新型的CRM1抑制剂，可使高密度MM细胞对阿霉素(DOX)和蛋白酶体抑制剂(PI)增敏。我们的中心假设是，破坏人类多发性骨髓瘤中CRM1蛋白-NES结合的分子显著地使多发性骨髓瘤细胞对现有的抗多发性骨髓瘤药物(目前包括DOX和PI)敏感。我们的目标是进一步确定特定的CRM1i(KPT-330)与其他抗MM药物联合使用在体外MM细胞系模型、体外MM患者细胞、小鼠模型以及最终在复发/难治性疾病患者的早期临床试验中的作用。为了解决这一假设并实现这些目标，我们提出了以下具体目标。具体目的1：利用体外MM细胞模型和体外人MM细胞模型，优化CRM1抑制剂KPT-330(Selinexor)与其他抗MM药物的相互作用。具体目标2：确定KPT-330与其他使用MM细胞株和原代MM细胞的抗MM药物之间的协同作用机制，并确定预测药物组合反应的生物标志物。特定目的3：利用人MM小鼠模型，确定体内最有效的KPT-330/抗MM药物组合(S)。特定目的4：采用上述确定的最佳给药方案，进行KPT-330和聚乙二醇化脂质体阿霉素治疗复发/难治性MM的早期试验。这项应用具有很高的创新性，因为它探索了一流药物(CRM1抑制剂)与已知活性药物在MM中的协同作用，包括使用KPT-330+PLD治疗复发/难治性MM的初始早期试验。临床试验办公室/第一阶段计划将监督早期试验，而组织核心将为细胞系提供QA/QC并监督人体组织采集。生物统计核心将帮助设计小鼠研究和早期试验，并提供对大型数据集的分析。

 DESCRIPTION (provided by applicant): Multiple myeloma (MM) accounts for about 10% of all hematologic malignancies, with estimated numbers of new cases and deaths for 2014 in the US at 24,050 and 11,090, respectively. Significant increases in response and survival have been seen over the last several years, largely due to the introduction of highly effective immunomodulatory agents, proteasome inhibitors, and the expanded use of high-dose chemotherapy and autologous stem cell transplant. Notwithstanding these significant advances, MM remains an incurable disease, and patients ultimately die from progressive disease refractory to anti-myeloma therapy. There is clearly a need for additional effective therapies. In our lab, we have shown that high-density human MM cells demonstrate de novo resistance to DNA topoisomerase II (topo II) inhibitors by transporting topo IIa from the nucleus to the cytoplasm. We have shown that chromosomal maintenance region 1 (CRM1 or XPO1) protein binds the nuclear export signals (NES) of topo IIa and that knockdown of CRM1 or its inhibition with small molecules results in the nuclear retention of topo IIa and re-sensitization of MM cells to topo II inhibitors. KPT-330, one of a new class of CRM1 inhibitors, sensitizes high-density MM cells to doxorubicin (DOX) and to proteasome inhibitors (PI). Our central hypothesis is that molecules that disrupt CRM1 binding of protein-NES in human MM significantly sensitize MM cells to existing anti-MM drugs (thus far including DOX and PIs). Our goals are to further define the role of a specific CRM1i (KPT-330) in the treatment of MM in combination with other anti-MM agents using in vitro MM cell lines models, ex vivo MM patient cells, mouse models, and ultimately early-phase clinical trials in patients with relapsed/refractory disease. To address thi hypothesis and achieve these goals, we propose the following specific aims. Specific Aim 1: To optimize the interactions between the CRM1 inhibitor KPT-330 (Selinexor) and other anti-MM drugs using in vitro MM cell line models and ex vivo human MM cells. Specific Aim 2: To define the mechanisms of synergy between KPT-330 and other anti-MM drugs using MM cell lines and primary MM cells and to define biomarkers predictive of response to the drug combinations. Specific Aim 3: To confirm the most effective KPT-330/anti-MM drug combination(s) in vivo using mouse models of human MM. Specific Aim 4: To perform an early-phase trial of KPT-330 and pegylated liposomal doxorubicin in relapsed/refractory MM using the optimal administration schedule defined above. This application is highly innovative in that it explores the synergism between a first-in-class agent (CRM1 inhibitor) combined with known active agents in MM, including an initial early-phase trial with KPT-330 + PLD in relapsed/refractory MM. The Clinical Trials Office/Phase I Program will oversee the early-phase trials, while the Tissue Core will provide QA/QC for cell lines and oversee human tissue acquisition. The Biostatistics Core will help design the mouse studies and early-phase trials and provide the analyses of large datasets.