Overcoming therapeutic resistance of gliomas

描述（由申请人提供）：溶瘤性单纯疱疹病毒(oHSV)-1的特定病毒基因突变已被证明对癌细胞具有选择性，这使得在人类中的转化研究成为可能。然而，只有一部分接种了oHSV-1的癌症患者在1期和2期临床试验中显示出客观的反应。我们最近发现了对oHSV介导的溶瘤有耐药性的GBM系。基于我们的研究结果，我们构建了重组oHSV-TRAIL，一种含有可分泌的促凋亡肿瘤坏死因子相关凋亡诱导配体（TRAIL）的oHSV，并假设oHSV-TRAIL可以作为一种基于机制的癌症治疗药物，靶向广谱的耐药肿瘤。在本提案中，我们将筛选一组从患者来源的原发性GBM细胞系中分离的胶质瘤干细胞（GSC），以确定它们对oHSV和TRAIL的敏感性，并鉴定对oHSV或oHSV和TRAIL都具有抗性的细胞系。基于我们对ohhsv -TRAIL处理的oHSV和TRAIL耐药胶质瘤细胞ERK下调、JNK和p38激活以及随后caspase上调的初步研究，我们假设oHSV将靶向细胞增殖途径，并诱导oHSV和/或TRAIL耐药的已建立胶质瘤细胞和原代GSCs进行TRAIL介导的凋亡。oHSV-S-TRAIL的疗效将在体外和小鼠模型中进行评估，这些模型是由鉴定的细胞系创建的，并最终在筛选一组新切除的患者肿瘤后鉴定的耐药细胞系中进行评估。将基因工程荧光（GFP和mCherry）和生物荧光（萤火虫荧光素酶、Fluc和Renilla荧光素酶、Rluc）成像标记结合到oHSV和胶质瘤细胞中，将使我们能够在体内跟踪oHSV的传递和传播；胶质瘤体积和侵袭的变化；通过体内生物发光成像（BLI）和活体显微镜（IVM）观察oHSV-TRAIL的疗效。我们预计我们的研究结果将对以下方面做出重大贡献：1)阐明oHSV介导的肿瘤溶解和TRAIL如何协同作用以靶向对病毒肿瘤溶解和/或细胞毒性治疗具有抗性的异质胶质瘤细胞的分子机制；2)最终为脑肿瘤患者开发新的基于oHSV的治疗方法。

DESCRIPTION (provided by applicant): Mutations of specific viral genes of oncolytic herpes simplex virus (oHSV)-1 have been shown to confer selectivity to cancer cells, which has enabled translational studies in humans. However, only a subset of cancer patients inoculated with oHSV-1 have shown objective response in phase 1 and 2 clinical trials. We have recently identified GBM lines that are resistant to oHSV mediated oncolysis. Based on our findings, we have created recombinant oHSV-TRAIL, an oHSV bearing a secretable pro-apoptotic tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and hypothesize that oHSV-TRAIL could be used as a cancer therapeutic to target a broad spectrum of resistant tumors in a mechanism based manner. In this proposal, we will screen a panel of glioma stem cells (GSC) isolated from patient derived primary GBM lines, for their sensitivity to oHSV and TRAIL and identify lines that are resistant to oHSV or both oHSV and TRAIL. Based on our preliminary studies on the downregulation of ERK, activation of JNK and p38 and subsequent up- regulation of caspases in oHSV and TRAIL resistant glioma cells treated with oHSV-TRAIL, we hypothesize that oHSV will target cell proliferation pathway and prime oHSV and/or TRAIL resistant established glioma cells and primary GSCs to TRAIL mediated apoptosis. The efficacy of oHSV-S-TRAIL will be evaluated in vitro and in mouse models created from identified lines and ultimately in resistant lines identified from screening a panel of freshly resected patient tumors. The incorporation of genetically engineered fluorescent (GFP and mCherry) and bioluminescent (firefly luciferase; Fluc and Renilla luciferase;Rluc) imaging markers into oHSV and glioma cells will allow us to follow delivery and spread of oHSV in vivo; changes in glioma volumes and invasion; and the efficacy of oHSV-TRAIL by in vivo bioluminescence imaging (BLI) and intravital microscopy (IVM). We anticipate that our findings will have a major contribution towards: 1) elucidating molecular mechanisms of how oHSV mediated oncolysis and TRAIL can function in concert to target heterogeneous glioma cells which are resistant to viral oncolysis and/or cytotoxic therapies; and 2) ultimately developing novel oHSV based therapies for patients with brain tumors. PUBLIC HEALTH RELEVANCE: In this proposal, we will evaluate the effect of novel oncolytic virus, oHSV-TRAIL in oHSV and TRAIL resistant established and primary glioma cells in culture and in vivo in mouse models of glioma. The developed agents and strategies will be designed to be clinically translatable and should have a major impact in understanding current therapies targeting resistant brain tumors and also developing future therapies for brain tumors.