Combination therapy to inhibit neuroblastoma growth

描述（申请人提供）：联合治疗抑制神经母细胞瘤生长神经母细胞瘤是最常见的儿童实体肿瘤，起源于交感神经系统。神经母细胞瘤肿瘤表现出与某些遗传畸变相关的临床和生物学异质性。晚期IV期神经母细胞瘤对所有常规治疗方法都是难治性的，并且预后很差。高风险IV期神经母细胞瘤儿童的治愈率仍低于20%，这为更好地了解靶向治疗这种疾病的分子机制提供了令人信服的理由。放疗仍然是控制恶性和良性肿瘤治疗方式的主要组成部分。对于残留或复发的良性肿瘤患者，人们越来越关注放射相关的副作用，即使使用高度精确的治疗方法，如放射外科手术，也可能发生。尽管有一定的治疗效果，但最近的证据表明，辐照可能通过激活涉及肿瘤侵袭、血管生成和转移的几种途径，在体外和体内促进癌细胞的恶性行为。辐射的另一个后果是肿瘤经常对辐射产生抗药性。越来越多的有晚期后遗症的长期幸存者强调需要新的治疗方法。肿瘤生长和血管生成发生在细胞外基质（ECM）的背景下，其水平和沉积部分由分泌蛋白控制，酸性和富含半胱氨酸（SPARC），一种基质细胞糖蛋白。SPARC调节细胞与ECM的相互作用，并在正常细胞中发挥多种作用，其中许多已被证明有助于肿瘤的发生。正常脑中SPARC的相对表达水平随着恶性转化而降低，这与我们组和其他人的研究结果一致。我们的初步研究表明，与亲代和EV转染的细胞相比，SPARC的过表达抑制了神经母细胞瘤细胞的增殖、迁移、血管生成和肿瘤生长。我们还提出SPARC可能作为放射治疗的增敏剂。我们假设将确定SPARC与放疗结合的调节以及这些治疗的抗癌效果。本提案的具体目的如下：在specific Aim 1中，我们将在体外和体内模型中评估p-SPARC和辐射单独或联合对神经母细胞瘤细胞迁移和侵袭的影响。在特异性目标2中，我们将确定p-SPARC和放疗（单独或联合）对神经母细胞瘤细胞生长、增殖、粘附和凋亡的影响。在Specific Aim 3中，我们将确定p-SPARC和辐射（单独或联合）对神经母细胞瘤细胞与体外和体内微环境相互作用的影响，以及p-SPARC和辐射（单独或联合）对体外和体内血管生成的影响。这种体外基础科学实验和体内转化研究的结合将为开发一种新的治疗方法提供基础，以治疗对传统放疗有抗性的神经母细胞瘤肿瘤。

DESCRIPTION (provided by applicant): Combination therapy to inhibit neuroblastoma growth Neuroblastoma is the most common pediatric solid tumor that arises from the sympathetic nervous system. Neuroblastoma tumors exhibit clinical and biological heterogeneity associated with certain genetic aberrations. Advanced state IV neuroblastoma is refractory to all conventional therapeutic modalities and is associated with a dismal prognosis. The cure rate of children with high-risk stage IV neuroblastoma remains at <20%, providing a compelling reasons to better understand the molecular mechanisms that can be targeted to treat this disease. Radiotherapy remains a major component of treatment modalities for controlling both malignant and benign tumors. In patients with residual or recurring benign tumors, there is increasing concern about radiation-related side effects that may occur even with highly accurate therapies such as radiosurgery. Despite some therapeutic effect, recent evidence has shown that irradiation may promote malignant behaviors of cancer cells both in vitro and in vivo by activating several pathways involved in tumor invasiveness, angiogenesis and metastasis. Another consequence of radiation is that tumors often become resistant to radiation. An increasing number of long-term survivors with late sequelae highlight the need for novel therapeutic approaches. Tumor growth and angiogenesis occur in the context of the extracellular matrix (ECM), the levels and deposition of which are controlled in part by secreted protein, acidic and rich in cysteine (SPARC), a matricellular glycoprotein. SPARC modulates cellular interaction with the ECM and has diverse roles in normal cells, many of which have been shown to contribute to tumorigenesis. The relative levels of SPARC expression in normal brain decreased with malignant transformation, as indicated by our group and others. Our preliminary studies demonstrated that over-expression of SPARC inhibited neuroblastoma cell proliferation, migration, angiogenesis and tumor growth in vivo compared to parental and EV- transfected cells. We also provided that SPARC may act as a sensitizer to radiotherapy. We hypothesize that modulation of SPARC combined with radiation and the anticancer effects of these treatments will be determined. The specific aims of this proposal are as follows: In Specific Aim 1, we will evaluate the effects of the p-SPARC and radiation, alone and in combination, on neuroblastoma cell migration and invasion in both in vitro and in vivo models. In Specific Aim 2, we will determine the effects of p-SPARC and radiation, alone and in combination, on neuroblastoma cell growth, proliferation, adhesion and apoptosis. In Specific Aim 3, we will determine the effect of p-SPARC and radiation, alone and in combination, on neuroblastoma cell interactions with the microenvironment of both in vitro and in vivo and the effect of p-SPARC and radiation, alone and in combination, on angiogenesis both in vitro and in vivo. This combination of in vitro basic science experiments and translational in vivo studies will provide the basis for development of a new therapeutic approach to neuroblastoma tumors which are resistant to conventional radiotherapy. PUBLIC HEALTH RELEVANCE: Neuroblastoma accounts for 10% of all juvenile cancers. Advanced stage neuroblastoma in children over one-year old is largely incurable using current treatment protocols. However, an increasing number of long-term survivals with secondary effects from this treatment highlighted the need for development of novel therapeutic approaches. This proposal represents a comprehensive analysis to determine the therapeutic benefit of SPARC expression in combination with radiation for the treatment of neuroblastoma.