P-2: Targeting telomerase expansion mechanism in MM

在前一个资助期，基于端粒功能的维持对 MM细胞存活，我们研究了MM维持端粒功能的机制并评估了 端粒酶/端粒抑制剂作为新的治疗药物。我们已经证明了端粒酶活性是 MM细胞和细胞系与正常浆细胞相比，端粒长度增加，端粒长度变短。 为使用端粒维持机制导向的新疗法提供关键的治疗指标。 我们进一步评估了MM中调节端粒酶活性的机制。 研究发现，MM的重要生存信号也是维持端粒酶活性的机制。我们 已经证明，诱导MM细胞增殖和存活的IL-6和IGF-1也增加 端粒酶活性；这些细胞因子通过NFkB介导的上调端粒酶活性 以及通过Akt介导的hTERT磷酸化和 激活。我们还进一步表明，HSP90与端粒酶活性形成络合物，并调节端粒酶活性； 相反，17-AAG抑制HSP90会导致端粒酶活性的抑制。最后，我们有 评价多种端粒酶抑制剂对多发性骨髓瘤的疗效，并确定GRN163L对MM的疗效 反义脂化寡核苷酸hTERT抑制剂在体外和体内的小鼠模型 在这一更新应用中，我们正在启动GRN163L在复发和 对于复发的难治性MM，我们将评估GRN163L治疗骨髓瘤的临床和分子疗效； 作为临床前、体外和体内模型中与端粒酶抑制有协同作用的药物。这个 在单药临床研究中确定的应答与耐药的分子相关性，加上 临床前鉴定具有协同抗多发性骨髓瘤活性的组合，将为 联合临床试验。为此，将追求以下目标：具体目标1：调查 端粒酶靶向GRN163L治疗复发患者的安全性、有效性和分子相关性 或难治性MM；具体目标2：合理定义端粒酶抑制物和新型 介导体外协同MM细胞毒作用的药物；以及特定目标3：确定体内疗效 端粒酶抑制剂联合疗法在人多发性骨髓瘤小鼠模型中的作用 临床研究。

In the previous funding period, based on the hypothesis that maintenance of telomere function is critical to MM cell survival, we investigated the mechanisms maintaining telomere function in MM and evaluated inhibitors of telomerase/telomeres as novel therapeutics. We have shown that telomerase activity is increased, while telomere length is shorter, in MM cells and cell lines compared to normal plasma cells, providing a critical therapeutic index for using telomere maintenance mechanism-directed novel therapeutics. We have further evaluated the mechanisms regulating telomerase activity in MM. Specifically, we have identified that the important MM survival signals are also mechanisms maintaining telomerase activity. We have demonstrated that IL-6 and IGF-1, which induce MM cell proliferation and survival, also increase telomerase activity; these cytokines augment telomerase activity through NFkB-mediated upregulation of both hTERT mRNA and protein expression; as well as through Akt-mediated hTERT phosphorylation and activation. We have also gone on to show that hsp90 complexes with and modulates telomerase activity; conversely, inhibition of hsp90 by 17-AAG leads to inhibition of telomerase activity. Finally, we have evaluated the effects of various inhibitors of telomerase in MM and identified efficacy of GRN163L, an antisense lipidated oligonucleotide hTERT inhibitor, both in vitro as well as in vivo in a murine model of human MM. In this renewal application, we are initiating a phase I study of GRN163L in relapsed and relapsed refractory MM, we will evaluate the clinical and molecular effects of GRN163L in myeloma; as well as identify agents that are synergistic with telomerase inhibition in preclinical in vitro and in vivo models. The molecular correlates of response versus resistance identified in the single agent clinical study, coupled with preclinical identification of combinations with synergistic anti-MM activity, will provide the framework for combination clinical trials. To this end, the following aims will be pursued: Specific Aim 1: To investigate safety, efficacy, and molecular correlates of telomerase-targeting GRN163L therapy in patients with relapsed or refractory MM; Specific Aim 2: To define rationally-based combinations of telomerase inhibitor and novel agents which mediate synergistic MM cytotoxicity in vitro; and Specific Aim 3: To define the in vivo efficacy of telomerase inhibitor combination therapies in murine models of human MM for translation to derived clinical studies.