Targeting Acid Ceramidase to Improve the Efficacy of Herpes Oncolytic Virus

项目摘要/摘要 神经鞘脂代谢失调与神经退行性疾病和癌症有关，但 神经酰胺和鞘氨醇-1磷酸之间的平衡对调节细胞命运至关重要，鞘磷脂 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为神经酰胺 到鞘氨醇，然后可以被鞘氨醇激酶1转化为鞘氨醇-1-磷酸。转变为 神经鞘氨醇-1-磷酸的产生可能使细胞逃避凋亡，而转向神经酰胺则可能 支持细胞死亡。在致命的脑肿瘤胶质母细胞瘤(GBM)中，鞘磷脂平衡向 1-磷酸鞘氨醇可由酸性神经酰胺酶(ASAH1)介导。ASAH1在GBM中高表达， 包括抗放射和耐化学药物的神经干细胞样脑肿瘤启动细胞。ASAH1抑制剂 增加促细胞凋亡的神经酰胺并阻止某些癌症类型的进展。支持潜力 靶向ASHA1用于抗GBM治疗，我们新的初步数据表明，血脑屏障 渗透性ASAH1抑制剂卡莫氟抑制BTIC细胞生长，下调ASAH1基因。最近的一份报告 用ASAH1基因敲除小鼠也证明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，特别是溶瘤疱疹病毒(OHSV)，已经证明有显著意义 在临床试验中改善儿童高级别胶质瘤的存活率。不幸的是，同样程度的 成人肾小球基底膜未见反应。综上所述，这些数据表明，靶向ASAH1可能 提高OHSV疗效。因此，我们将确定ASAH1的基因或药物抑制是否增加 OHSV介导的双亲BTICs和替莫唑胺耐药患者BTICs的细胞死亡 异种移植物。我们还将探索在肿瘤中靶向ASAH1是否有其他好处 微环境通过对胶质瘤相关巨噬细胞/小胶质细胞的影响。我们预计这些研究 将提供关键的初步数据来支持更大规模的研究计划，以确定 转移鞘磷脂变阻器是改善GBM免疫病毒治疗的有效治疗策略。

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.