Proteasome inhibitor (PS-341) and adoptive immunotherapy

描述(由申请人提供)：蛋白酶体抑制剂作为一种单一药物在癌症治疗中显示出希望。我们最近观察到蛋白酶体抑制剂PS-341可以使肿瘤细胞对TRAIL介导的死亡敏感。这种敏化是通过下调c-flip的表达来实现的，c-flip是防止细胞凋亡的重要介质。令人惊讶的是，在一些肿瘤株中，这种增敏活性也被证明是独立于核因子-kappaB的。我们现在希望扩大这些发现，以确定蛋白酶体抑制是否可以与过继免疫治疗的杀伤潜力和骨髓移植(BMT)前广泛的细胞还原调节一起使用。为此，提出了几个特定的目标：特定的目标1将扩展到体外研究，并检查PS-341和TRAIL的基因构建体(FC-TRAIL)或最近获得的激动剂TRAIL受体抗体(抗DR5)对晚期荷瘤小鼠的影响。 抗肿瘤作用的机制也将用TRAIL KO小鼠进行剖析。具体目标2将评估PS-341在有或没有FC-TRAIL或抗DR5的情况下，在携带肿瘤的小鼠接受骨髓移植(BMT)的最小残留病模型中的效果。将使用同基因和异基因骨髓移植，并将评估对免疫和髓系重建以及肿瘤复发的影响。在异基因骨髓移植模型中，对移植物抗宿主病(GVHD)的影响将被确定。最后，在具体目标3中，将通过体外和体内试验来确定PS-341作为一种手段来增强肿瘤细胞对T和NK细胞杀伤的效果。这将最终结合从先前的特定目标获得的数据，并评估PS-341与NK细胞和抗DR5作为一种过继免疫疗法在静息荷瘤小鼠和骨髓移植后荷瘤小鼠中的效果。这些结果将允许评估PS-341与免疫治疗结合使用各种肿瘤类型和在临床前相关模型中抑制蛋白酶体的有效性。

DESCRIPTION (provided by applicant): Proteasome inhibitors have shown promise in cancer therapy as a single agent. We have recently observed that the proteasome inhibitor, PS-341, can sensitize neoplastic cells to TRAIL-mediated death. This sensitization occurred through the down-regulation of c-FLIP, an important mediator in the prevention of apoptosis. Surprisingly, this sensitizing activity was also shown to be independent of NF-kappaB in some tumor lines. We now wish to extend these findings to ascertain if proteasome inhibition can be used in conjunction with the killing potential of adoptive immunotherapy and the extensive cytoreductive conditioning that precedes bone marrow transplantation (BMT). To do this, several Specific Aims are proposed: Specific Aim 1 will extend on the in vitro studies and examine the effects of PS-341 and a genetic construct for TRAIL (Fc-TRAIL) or a recently obtained agonist TRAIL receptor antibody (anti-DR5) on advanced tumor-bearing mice. The mechanism underlying the anti-tumor effects will also be dissected using TRAIL KO mice. Specific Aim 2 will assess the effects of PS-341, with or without Fc-TRAIL or anti-DR5, in a minimal residual disease model in which the tumor-bearing mice receive a bone marrow transplant (BMT). Both syngeneic and allogeneic BMT will be used and effects on immune and myeloid reconstitution as well as tumor relapse will be assessed. In allogeneic BMT models, effects on graft-versus-host disease (GVHD) will be ascertained. Finally, in Specific Aim 3, effects of PS-341 as a means to sensitize tumor cells to T and NK cell killing will be determined using both in vitro and in vivo assays. This will culminate with combining the data attained from the previous specific aims and assessing the effects of PS-341 with NK cells and anti-DR5 as an adoptive immunotherapy regimen in resting tumor-bearing mice and in tumor-bearing mice after BMT. These results will allow for the assessment of the efficacy of proteasome inhibition with PS-341 in conjunction with immunotherapy using a variety of tumor types and in preclinically-relevant models.