Multi-Modal Lysosomotropic Death Therapy for Malignant Peripheral Nerve Sheath Tu

描述(申请人提供)：恶性周围神经鞘瘤(MPNST)是侵袭性的、迅速致命的肿瘤，迫切需要新的治疗方法。MPNSTs发生在高达10%的1型神经纤维瘤病(NF1)患者中，并且对标准化疗药物具有高度耐药性。近十年来，我们一直在研究溶酶促进剂氯喹(CQ)的细胞死亡促进活性，发现CQ在多种正常和恶性神经细胞中诱导自噬应激和caspase激活。我们假设CQ诱导的死亡是由于抑制促进生存的自噬途径和刺激凋亡和非凋亡死亡途径所致。重要的是，CQ诱导的细胞死亡涉及P53依赖和P53非依赖两种途径，鉴于人类MPNSTs在高达75%的病例中显示P53突变或缺失，P53非依赖的死亡途径可能对有效的MPNST治疗特别关键。CQ最近被报道在几种癌症动物模型和人类多形性胶质母细胞瘤(GBM)患者的治疗中是标准化疗药物的有效佐剂。预防性给予CQ也被报道在转基因小鼠模型中抑制淋巴瘤的形成和动脉粥样硬化性疾病。我们最近发现，几种与CQ相关的化合物，包括喹卡林(QA)和甲氟喹(MQ)，在体外对MPNST细胞的杀伤能力是CQ的10倍。QA和MQ都比CQ具有更好的神经系统渗透性，并已被安全地用于人类作为抗疟疾药物。我们还发现了一些FDA批准的喹诺酮类抗生素，它们具有溶酶体趋化特性，在体外对MPNST细胞显示出显著的杀瘤活性。在这一应用中，我们将重点研究CQ、QA、MQ和其他杀瘤溶酶促进剂促进MPNST细胞死亡的分子途径，并将通过将MPNST细胞系原位移植到裸鼠体内和转基因小鼠MPNST肿瘤发生和发展模型来关键地测试这些化合物的治疗潜力。在第一个目标中，我们将验证CQ和其他溶酶体趋化剂通过凋亡和自噬死亡途径诱导MPNST细胞死亡的假设，这些死亡途径至少部分受组织蛋白亚细胞分布和活性的改变、内在凋亡死亡途径的Bax激活和自噬中断的调节。目的检测CQ相关化合物和喹诺酮类抗生素的体内杀瘤活性及其作为MPNST预防药物在健壮的MPNST小鼠模型中的应用。总之，这些高度集成的MPNST研究将扩展我们之前对细胞凋亡和自噬死亡途径的研究，为溶酶体治疗和预防MPNST的临床应用提供新的见解，并为未来在NF1和MPNST患者中开展CQ相关化合物和喹诺酮类抗生素的人类研究提供坚实的基础。公共卫生相关性：恶性周围神经鞘瘤(MPNST)是侵袭性肿瘤，发生在大约10%的1型神经纤维瘤病(NF1)患者以及相当数量的非NF1患者中。我们发现多种溶酶促进剂，如氯喹、喹啉和喹诺酮类抗生素，在体外具有显著的MPNST杀伤活性。本申请旨在确定它们的杀瘤作用机制，并在MPNSTs的小鼠模型中测试这些溶酶体趋化化合物。

DESCRIPTION (provided by applicant): Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, rapidly fatal neoplasms for which new therapeutic approaches are desperately needed. MPNSTs occur in up to ten percent of patients with neurofibromatosis type 1 (NF1) and are highly resistant to standard chemotherapeutic agents. We have been investigating the cell death promoting activities of chloroquine (CQ), a lysosomotropic agent, for almost ten years and have found that CQ induces autophagic stress and caspase activation in a variety of normal and malignant neural cell types. We have hypothesized that CQ-induced death results from inhibition of pro- survival autophagic pathways and stimulation of both apoptotic and non-apoptotic death pathways. Importantly, CQ-induced cell death involves both p53-dependent and p53-independent pathways and given that human MPNSTs show p53 mutations or deletions in up to 75% of cases, p53-independent death pathways may be particularly critical for effective MPNST therapy. CQ has recently been reported to be a potent adjuvant to standard chemotherapeutic agents in several animal models of cancer and in the treatment of human glioblastoma multiforme (GBM) patients. Prophylactic CQ administration has also been reported to inhibit both lymphoma formation and atherosclerotic disease in transgenic mouse models of these conditions. We recently found that several CQ-related compounds, including quinacrine (QA) and mefloquine (MQ), have ten-fold greater potency than CQ in killing MPNST cells in vitro. Both QA and MQ have better nervous system penetration than CQ and have been used safely in humans as anti-malarial agents. We have also discovered a number of FDA approved quinolone antibiotics with lysosomotropic properties that show significant tumoricidal activity on MPNST cells in vitro. In this application, we focus on the molecular pathways by which CQ, QA, MQ and other tumoricidal lysosomotropic agents promote MPNST cell death and will critically test the therapeutic potential of these compounds using orthotopic transplantation of MPNST cell lines in nude mice and transgenic mouse models of MPNST tumorigenesis and progression. In aim one, we will test the hypothesis that CQ and other lysosomotropic agents induce MPNST cell death through both apoptotic and autophagic death pathways that are at least in part regulated by altered subcellular distribution and activity of cathepsins, Bax activation of the intrinsic apoptotic death pathway, and disrupted autophagy. Aim two will test the in vivo tumoricidal activity of CQ-related compounds and quinolone antibiotics and their utility as MPNST prophylactic agents in robust mouse models of MPNSTs. In total, these highly integrated studies of MPNSTs will extend our previous investigations of apoptotic and autophagic death pathways, yield new insights into the clinical utility of lysosomotropic therapies for MPNST treatment and prevention, and provide a solid foundation from which to propose future human studies of CQ-related compounds and quinolone antibiotics in NF1 and MPNST patients. PUBLIC HEALTH RELEVANCE: Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive neoplasms that arise in approximately 10% of patients with neurofibromatosis type 1 (NF1) as well as in a significant number of non-NF1 patients. We have found that a variety of lysosomotropic agents such as chloroquine, quinacrine and quinolone antibiotics have significant MPNST killing activity in vitro. This application aims to define their mechanism of tumoricidal action and to test these lysosomotropic compounds in mouse models of MPNSTs.