OSU-03012 therapy for glioblastoma

描述（由申请人提供）：多形性胶质母细胞瘤（GBM）是最致命的恶性肿瘤之一，部分原因是其高度侵袭性，以及由于GBM细胞对放射或化学治疗的相对抗性。从非甾体抗炎药塞来昔布的化学主干中衍生出一系列化合物，这些化合物不具有COX2抑制活性，但具有很高的生物利用度，可以穿过血脑屏障，并且在抑制肿瘤细胞活力方面比母体药物更有效。我们已经证明，最有效的先导化合物OSU-03012在体外培养的已建立和原代人GBM细胞中引起强烈的诱导细胞死亡，但在未转化的原代星形胶质细胞或原代肝细胞的培养中，浓度在1-5 μ M范围内，低于该药物在啮齿动物中可达到的15-20 μ M血浆浓度。该化合物被NCI RAID项目选中进行开发，部分基于我们的数据，该药物作为单一药物的I期试验将于2009年开始用于其他肿瘤类型。我们已经在原代和已建立的人GBM细胞中证明，OSU-03012在体外抑制短期活力和集落形成，并且OSU-03012诱导的杀伤主要通过诱导毒性内质网（ER）应激/自噬信号发生。在体内，我们在一个GBM模型中注意到，OSU-03012可以提高动物存活率，并与放疗相互作用，进一步延长生存期。我们已经发表了OSU-03012的致死率通过抑制HSP90或暴露于电离辐射而被放大。我们假设：格尔达霉素HSP90激动剂通过ROS和神经酰胺产生引起CD95激活，与OSU-03012诱导的毒性自噬平行，这是GBM细胞杀伤的协同作用。我们假设：电离辐射通过促进神经酰胺合成酶基因的表达/激活，从而增强OSU-03012诱导的毒性自噬，从而增强OSU-03012的毒性。特异性目标1：将确定暴露于HSP90拮抗剂（格尔达霉素）17AAG / 17DMAG促进OSU-03012对原代人GBM细胞毒性的分子机制。特异性目标2：将确定OSU-03012放射致敏人GBM原代细胞的分子机制，特别关注神经酰胺合酶基因的调节作用。特异性目的3：通过原位移植人GBM细胞模型，确定OSU-03012在体内是否能增强电离辐射或17AAG的杀瘤作用。本提案中研究的目标是提供详细的机制证据，将OSU-03012作为GBM的治疗药物从实验室转移到临床。

DESCRIPTION (provided by applicant): Glioblastoma multiforme (GBM) is one of the most lethal malignancies in part due to its highly invasive nature and due to the relative resistance of GBM cells to fully respond to radio- or chemo-therapies. A series of compounds have been derived from the chemical backbone of the NSAID Celecoxib that do not possess COX2 inhibitory activity, but are highly bio-available, can cross the blood-brain barrier, and are an order of magnitude more potent at suppressing tumor cell viability than the parent drug. We have shown that the most potent lead compound, OSU-03012, causes a strong induction cell death in established and primary human GBM cells in vitro, but not in cultures of non-transformed primary astrocytes or primary hepatocytes, at concentrations in the 1-5 ¿M range, which is lower than the 15-20 ¿M achievable plasma concentration of this agent in rodents. This compound was selected by the NCI RAID program for development, in part based on our data, and a phase I trial with this drug as a single agent will commence in other tumor types in 2009. We have demonstrated in primary and established human GBM cells that OSU-03012 suppresses short-term viability and colony formation in vitro and that OSU-03012 -induced killing occurs primarily via in the induction of a toxic endoplasmic reticulum (ER) stress / autophagy signal. In vivo we have noted in one GBM model that OSU-03012 can enhance animal survival and interact with radiotherapy to further prolong survival. We have published that the lethality of OSU-03012 is magnified by inhibition of HSP90 or by exposure to ionizing radiation. We hypothesize that: geldanamycin HSP90 agonists via ROS and ceramide production cause CD95 activation in parallel to OSU-03012 -induced toxic autophagy which is responsible for the synergy of GBM cell killing. We hypothesize that: ionizing radiation enhances OSU-03012 toxicity by promoting expression/ activation of ceramide synthase genes which enhances OSU-03012 -induced toxic autophagy. Specific Aim 1: Will determine the molecular mechanism(s) by which OSU-03012 toxicity in primary human GBM cells is promoted by exposure to the HSP90 antagonists (geldanamycins) 17AAG / 17DMAG. Specific Aim 2: Will determine the molecular mechanisms by which OSU-03012 radio-sensitizes primary human GBM cells with specific focus on the regulatory roles of ceramide synthase genes. Specific Aim 3: Will determine, using orthotopic xenograft models of primary human GBM cells, whether OSU-03012 enhances the tumoricidal effects of ionizing radiation or of 17AAG, in vivo. The goal of the studies in this proposal is to provide detailed mechanistic evidence to move OSU-03012 as a therapeutic for GBM from the bench into the clinic. PUBLIC HEALTH RELEVANCE: OSU-03012 was licensed in 2008 to a biotechnology company (Arno) in part based on our data published in three manuscripts, and a phase I trial with this drug as a single agent will commence in 2009 in a variety of malignancies but not with any likely accrual in GBM patients. The goal of the studies in this proposal is to determine in molecular detail using primary human GBM cells the mechanisms of action of OSU-03012 as a single agent and in combination with ionizing radiation; and in combination with geldanamycins to inhibit HSP90 function. Our goal is to provide detailed mechanistic evidence to move OSU-03012 as a therapeutic for GBM into the clinic.