Targeting Acid Ceramidase to Improve the Efficacy of Herpes Oncolytic Virus

项目概要/摘要 鞘脂代谢失调与神经退行性疾病和癌症有关，但神经退行性疾病和癌症的发生与鞘脂代谢失调有关。 神经酰胺和鞘氨醇-1磷酸之间的平衡对于调节细胞命运至关重要， 变阻器，在神经干细胞或脑肿瘤中的研究较少。神经酰胺可以被神经酰胺酶转化 转化为鞘氨醇，然后鞘氨醇激酶1将其转化为鞘氨醇-1-磷酸。移向 鞘氨醇-1-磷酸的产生可能使细胞逃避凋亡，而向神经酰胺的转移可能 有利于细胞死亡。在致命的脑肿瘤胶质母细胞瘤（GBM）中， 鞘氨醇-1-磷酸可由酸性神经酰胺酶（ASAH 1）介导。ASAH 1在GBM中高度表达， 包括放射和化学抗性神经干细胞样脑肿瘤起始细胞。ASAH 1抑制剂 增加促凋亡神经酰胺并阻断某些癌症类型的进展。支持潜力 针对ASHA 1进行抗GBM治疗，我们新的初步数据表明，血脑屏障 渗透剂ASAH 1抑制剂卡莫氟与ASAH 1敲低一样降低BTIC细胞生长。最近的一份报告 使用Asah 1基因敲除小鼠也证明了巨噬细胞中的酸性神经酰胺酶抑制疱疹病毒 传播免疫病毒疗法，特别是溶瘤性疱疹病毒（oHSV），已证明显着 临床试验中儿童高级别胶质瘤生存率的提高。不幸的是，同样程度的 在成人GBM中未观察到反应。总之，这些数据表明，靶向ASAH 1可能 改善oHSV功效。因此，我们将确定ASAH 1的遗传或药理学抑制是否增加 来源于亲本和替莫唑胺抗性患者来源的BTIC的oHSV介导的细胞死亡 异种移植我们还将探索在肿瘤中靶向ASAH 1是否有额外的益处。 通过对神经胶质瘤相关巨噬细胞/小胶质细胞的影响，改善微环境。我们预计这些研究 这里提出的将提供关键的初步数据，以支持一个更大的研究计划，以确定是否 改变鞘脂变阻器是改善GBM中免疫病毒疗法的有效治疗策略。

PROJECT SUMMARY/ABSTRACT Dysregulated sphingolipid metabolism is associated with neurodegenerative disorders and cancer, but the balance between ceramides and sphingosine-1 phosphate that is critical for regulating cell fate, the sphingolipid rheostat, is less well-studied in neural stem cells or brain tumors. Ceramides can be converted by ceramidases to sphingosine, which can then be converted by sphingosine kinase 1 to sphingosine-1-phosphate. Shifts toward sphingosine-1-phosphate production may allow cells to evade apoptosis, while shifts toward ceramides may favor cell death. In the deadly brain tumor glioblastoma (GBM), a shift in the sphingolipid balance towards sphingosine-1-phosphate can be mediated by acid ceramidase (ASAH1). ASAH1 is highly expressed in GBM, including in the radio- and chemoresistant neural stem cell-like brain tumor initiating cells. ASAH1 inhibitors increased pro-apoptotic ceramides and blocked the progression of some cancer types. Supporting the potential of targeting ASHA1 for anti-GBM treatments, our novel preliminary data demonstrated that the blood brain barrier penetrant ASAH1 inhibitor, carmofur, reduced BTIC cell growth as did ASAH1 knockdown. A recent report using Asah1 knockout mice also demonstrated that acid ceramidase in macrophages inhibited herpes virus propagation. Immunovirotherapy, specifically oncolytic herpes virus (oHSV), has demonstrated significant improvement in survival for pediatric high-grade glioma in clinical trials. Unfortunately, the same extent of response has not been observed in adult GBM. Together, these data suggest that targeting of ASAH1 may improve oHSV efficacy. We will, therefore, determine if genetic or pharmacologic inhibition of ASAH1 increases oHSV-mediated cell death of BTICs derived from parental and temozolomide-resistant patient-derived xenografts. We will also explore whether there are additional benefits for targeting ASAH1 in the tumor microenvironment through effects on glioma associated macrophages/microglia. We anticipate that the studies proposed here will provide key preliminary data to support a larger research program to determine whether shifting the sphingolipid rheostat is an effective therapeutic strategy to improve immunovirotherapy in GBM.