P- 3: Potentiating Proteasome Inhibitor Activity in NHL

蛋白酶体抑制剂(Pis)，如Bortezomib(Btzmb)，通过 多种机制，包括核因子-KB激活，氧化损伤诱导，内质网应激促进，其中 其他。Btzmb在多发性骨髓瘤和几种类型的非霍奇金淋巴瘤中显示出显著的活性 (非霍奇金淋巴瘤)，促使第二代蛋白酶体抑制剂(例如PR-171)的开发，它可能 与Btzmb相比，具有更好的PK/PD特性。然而，需要改善非霍奇金淋巴瘤的PI活性 坚持不懈。来自我们实验室的最新证据表明，将PI与其他临床相关的 靶向药物，包括HDAC或小分子Bcl-2抑制剂，导致协同诱导 非霍奇金淋巴瘤细胞系的细胞凋亡。这个项目的目标是阐明，使用弥漫性大B细胞淋巴瘤 (DLBCL)模型，PR-171与这些其他靶向药物之间的协同作用机制，扩展了这些 体内模型系统的发现，识别基于实验室的反应决定因素，并使用这一点 在难治性非霍奇金淋巴瘤患者中启动新的联合I期试验的信息。在具体目标1中，我们 将确定非霍奇金淋巴瘤细胞中Pis和HDAC抑制剂(Voinostat)之间的协同作用是否反映了核因子-KB 干扰、氧化损伤的诱导、内质网应激，或这些因素的组合。在具体目标2中，我们 将确定Pis和小分子Bcl-2抑制剂(例如GX15-070)之间的协同作用是否 氧化损伤，激活与压力相关的信号通路，和/或Bak和Bax的激活。我们会 还要确定a)这些方法在耐Btzmb的DLBCL细胞中是否有效；以及b)以下哪种方法 这些单独的策略可能最适合于特定的DLBCL亚型，即生发中心(GC) 与激活的B细胞(ABC)相比。在具体目标3中，我们将把这些发现推广到异种移植DLBCL模型。 系统，并确定协同作用的体外决定因素是否在体内起作用。在具体目标4中， 我们将选择目标1-3中最有希望的方案作为一个或多个阶段I PIS与HDAC或小分子Bcl-2抑制剂联合治疗难治性非霍奇金淋巴瘤的试验。我们会 还进行相关的实验室研究，以验证体内协同作用的机制，并确定 疾病反应的替代标记物。预计这些研究将为以下工作奠定基础 新的和潜在更有效的基于PI的治疗难治性非霍奇金淋巴瘤患者的策略。

Proteasome inhibitors (Pis) such as Bortezomib (Btzmb), induce apoptosis in neoplastic cells through multiple mechanisms, including NF-KB activation, oxidative injury induction, an ER stress promotion, among others. Btzmb displays marked activity in multiple myeloma, and several types of non-Hodgkin's lymphoma (NHL), prompting the development of second generation proteasome inhibitors (e.g., PR-171) which may have superior PK/PD characteristics compared to Btzmb. However, the need to improve PI activity in NHL persists. Recent evidence from our laboratory suggests that combining Pis with other clinically relevant targeted agents, including HDAC or small molecule Bcl-2 inhibitors results in synergistic induction of apoptosis in NHL cell lines. The goal of this project is to elucidate, using a diffuse large B-cell lymphoma (DLBCL) model, mechanisms of synergism between PR-171 and these other targeted agents, extend these findings to an in vivo model system, identify laboratory-based response determinants, and use this information to initiate novel combination Phase I trials in patients with refractory NHL. In Specific Aim #1, we will determine whether synergism between Pis and HDAC inhibitors (vorinostat) in NHL cells reflects NF-KB disruption, induction of oxidative injury, ER stress, or a combination of these factors. In Specific Aim #2, we will determine whether synergism between Pis and small molecule Bcl-2 inhibitors (e.g. GX15-070) stems from oxidative injury, activation of stress-related signaling pathways, and/or Bak and Bax activation. We will also establish a) whether these approaches are effective in Btzmb-resistant DLBCL cells; and b) which of these individual strategies might be most appropriate for specific DLBCL sub-types i.e., germinal center (GC) versus activated B-cell (ABC). In Specific Aim #3, we will extend these findings to a xenograft DLBCL model system, and determine whether in vitro determinants of synergism are operative in vivo . In Specific Aim #4, we will select the most promising of regimens emanating from Aims #1-3 to pursue as one or more Phase I trials combining Pis with HDAC or small molecule Bcl-2 inhibitors in patients with refractory NHL. We will also conduct correlative laboratory studies to validate mechanisms of in vivo synergism, and identify surrogate markers of disease responsiveness. It is anticipated that these studies will lay the foundation for novel and potentially more effective Pi-based strategies in patients with refractory NHL.