Cancer-specific nanoparticle-mediated gene therapy to treat hepatocellular carcinoma

 描述（由申请人提供）：拟议工作的目标是创建一个新的基因递送平台，以成像和杀死人类肝癌，特别是肝细胞癌（HCC）。目前的标准护理治疗采用化疗，其通常经动脉递送以增强对肿瘤组织的治疗定位。然而，经动脉化疗仅被证明对姑息治疗有效，并且经常导致周围健康肝组织的损伤，这可能导致肝功能衰竭和死亡。我们建议通过设计一种新的药物输送系统来解决这一问题，该系统可以增强肿瘤杀伤力，同时减少对健康细胞的损害。我们将提供编码单纯疱疹病毒胸苷激酶（HSVtk）的DNA，并使用HSVtk将前药更昔洛韦（GCV）转化为细胞杀伤药物。HSVtk DNA将使用聚合物纳米颗粒进行递送，我们将设计这些纳米颗粒以选择性地将DNA递送到HCC，从而实现癌症特异性细胞杀伤。我们将通过设计新的质粒启动子来限制HSVtk在HCC细胞中的表达，从而进一步提高HCC的选择性。我们将使用小鼠原位人HCC模型经动脉给予这些纳米颗粒，以模拟目前用于HCC治疗的微创手术技术。HSVtk还磷酸化核苷类似物（放射性示踪剂），使它们通过PET成像可见，这将使我们能够在体内成像和监测肿瘤。 基于初步工作，我们假设我们将能够设计纳米颗粒和质粒，限制对人HCC的细胞杀伤，同时避免对人肝细胞的脱靶效应。我们假设，这种传递系统将能够延长原位人肝癌小鼠模型的存活时间，同时能够在体内进行肿瘤成像。在具体目标1中，我们将证明通过纳米颗粒向九种人HCC细胞系递送癌症特异性基因，与体外三种人肝细胞系相比，并进一步检查小鼠原位人HCC模型中的这种选择性。此外，我们将研究这些纳米颗粒表现出癌症选择性的机制，这可能有助于阐明未来如何进一步改进癌症靶向纳米颗粒。在具体目标2中，我们将设计一个转录启动子，使肝癌特异性基因表达，并提供这种质粒使用纳米粒子，以证明在体外和体内增强癌症特异性。在具体目标3中，我们将证明HSVtk/GCV细胞杀伤系统在体外和体内的功效和癌症选择性，此外还使用HSVtk和放射性示踪剂在小鼠原位肿瘤模型中对人HCC进行成像。这项研究的最终目标是创造一种癌症特异性，治疗诊断和微创治疗方法 for human人HCC肝癌.

 DESCRIPTION (provided by applicant): The goal of the proposed work is to create a novel gene delivery platform to image and kill human liver cancer, specifically hepatocellular carcinoma (HCC). Current standard of care treatments employ chemotherapy, which is often delivered transarterially to enhance localization of treatment to the tumor tissue. However, transarterial chemotherapy has only proven effective for palliative care, and often results in damage to surrounding healthy liver tissue which can lead to liver failure and death. We propose to address this concern by designing a novel drug delivery system that could enhance tumor killing while reducing damage to healthy cells. We will deliver DNA encoding herpes simplex virus thymidine kinase (HSVtk), and use HSVtk to convert the prodrug ganciclovir (GCV) into a cell-killing drug. HSVtk DNA will be delivered using polymeric nanoparticles which we will engineer to selectively deliver DNA to HCC, thus enabling cancer specific cell killing. We will further promote HCC selectivity by designing novel plasmid promoters that restrict HSVtk expression to HCC cells. We will administer these nanoparticles transarterially using a mouse orthotopic model of human HCC to mimic the minimally invasive surgical technique currently employed in HCC therapy. HSVtk also phosphorylates nucleoside analogs (radiotracers), making them visible via PET imaging, which will enable us to image and monitor the tumor in vivo. Based on preliminary work, we hypothesize that we will be able to engineer both nanoparticles and plasmids that restrict cell killing to human HCC while avoiding off-target effects to human hepatocytes. We hypothesize that this delivery system will enable prolonged survival in an orthotopic human HCC mouse model while simultaneously enabling tumor imaging in vivo. In Specific Aim 1 we will demonstrate cancer- specific gene delivery via nanoparticles to nine human HCC lines as compared to three human hepatocyte cell lines in vitro, and further examine this selectivity in a mouse orthotopic human HCC model. Additionally, we will examine the mechanism by which these nanoparticles exhibit cancer selectivity, which may help to elucidate how cancer-targeting nanoparticles can be improved even further in the future. In Specific Aim 2, we will design a transcriptional promoter that enables HCC-specific gene expression, and deliver this plasmid using nanoparticles to demonstrate enhanced cancer specificity both in vitro and in vivo. In Specific Aim 3, we will demonstrate the efficacy and cancer selectivity of the HSVtk/GCV cell killing system in vitro and in vivo, in addition to using HSVtk and a radiotracer to image human HCC in a mouse orthotopic tumor model. The ultimate goal of this research is to create a cancer-specific, theranostic, and minimally invasive treatment for human HCC.