Nanoparticles for Selective Theranostic DNA Delivery to Liver Cancer

我们这个项目的总体目标是开发下一代纳米颗粒，用于靶向治疗 肝细胞癌（HCC）。包括HCC在内的肝癌在癌症发病率中排名第六， 是全球癌症死亡率的第二大原因。虽然手术或肝移植可以治愈，但大多数 患者表现为侵袭性HCC并且仅适合于姑息性和局部区域治疗。广泛 细胞毒性治疗，包括化疗和放疗，对健康肝细胞具有脱靶毒性， 由于潜在肝病的高发病率，这对HCC患者特别危险。因此，我们认为， 迫切需要一种有效且高度靶向的肝癌治疗选择。为此，我们提议 为HCC肿瘤开发高度靶向的纳米颗粒基因递送策略。我们的初步数据显示 生物可降解聚合物纳米载体PBAE 536可用于选择性地转染HCC细胞， 健康的肝细胞。治疗基因的肿瘤特异性递送将使靶向癌细胞 对周围健康肝组织的脱靶细胞毒性降低。然而，治疗 这种靶向纳米技术的潜力还有待实现。临床开发的进展是 这取决于1）用于体内使用的纳米颗粒的优化和2）安全、有效的 与该递送系统相容的治疗性DNA。 在这项提案中，我们将解决这两个障碍，并在人类临床前模型中测试最终的治疗方法。 HCC。在具体目标1中，我们将制定和评估PBAE纳米颗粒用于基因递送到原位， 小鼠肝肿瘤。纳米颗粒将通过静脉注射全身给药，并且脱靶 还将评估递送和转染。在具体目标2中，我们将开发治疗诊断DNA载体 针对HCC。我们将使用胸苷激酶自杀基因（SR 39），一种双功能基因产物，（1） 将前体药物更昔洛韦转化为抗癌化合物，和（2）磷酸化放射性标记的核苷 类似物，使PET成像的基因表达。为了增强肿瘤靶向性，我们将使用甲胎蛋白 (AFP)转录靶向，我们预计这将限制SR 39在肝癌细胞中的表达。工程AFP- 将在体外评估SR 39载体在HCC细胞和脱靶健康细胞中的治疗性基因表达 类型在特定目标3中，我们将联合收割机PBAE纳米颗粒与我们的新型转录靶向 用于在鼠异种移植肝肿瘤模型中测试的治疗诊断质粒。我们假设系统地 施用的PBAE纳米颗粒将使SR 39能够递送至HCC肿瘤，以安全有效地杀死癌症。 和分子遗传成像。如果成功，这个跨学科的项目将导致一种新的精确方法 适用于临床使用的HCC治疗。

Our overall goal of this project is to develop a next-generation nanoparticle for targeted treatment of hepatocellular carcinoma (HCC). Liver cancer, including HCC, has the sixth highest cancer incidence and is the second leading cause of cancer mortality worldwide. While surgery or liver transplantation can be curative, most patients present with invasive HCC and are only eligible for palliative and locoregional treatments. Broadly cytotoxic treatments, including chemotherapy and radiation, have off-target toxicities to healthy hepatocytes, which is particularly dangerous to HCC patients due to a high incidence of underlying liver disease. Therefore, there is a critical need for a potent and highly targeted treatment option for liver cancer. To this end, we propose to develop a highly targeted nanoparticle gene delivery strategy for HCC tumors. Our preliminary data suggests that the biodegradable polymeric nanocarrier PBAE 536 can be used to selectively transfect HCC cells over healthy hepatocytes in vitro. Tumor-specific delivery of a therapeutic gene would enable targeted cancer cell killing with reduced off-target cytotoxicity to the surrounding healthy liver tissue. However, the therapeutic potential of this targeted nanotechnology has yet to be realized. The progress of clinical development is dependent on 1) optimization of nanoparticles for in vivo use and 2) the development of a safe, effective therapeutic DNA which is compatible with this delivery system. In this proposal, we will address both hurdles and test the final therapeutic in a preclinical model of human HCC. In Specific Aim 1, we will formulate and evaluate PBAE nanoparticles for gene delivery to orthotopic murine liver tumors. Nanoparticles will be systemically administered by intravenous injection, and off-target delivery and transfection will also be assessed. In Specific Aim 2, we will develop of a theranostic DNA vector targeted to HCC. We will use a thymidine kinase suicide gene (SR39), a dual-functional gene product that (1) converts the prodrug ganciclovir into a cancer-killing compound and (2) phosphorylates radiolabeled nucleoside analogs to enable PET imaging of gene expression. To enhance tumor targeting, we will employ α-fetoprotein (AFP) transcriptional targeting, which we expect will restrict SR39 expression to HCC cells. Engineered AFP- SR39 vectors will be assessed in vitro for therapeutic gene expression in HCC cells and off-target healthy cell types. In Specific Aim 3, we will combine PBAE nanoparticles with our novel transcriptionally targeted theranostic plasmid for testing in a murine xenograft liver tumor model. We hypothesize that systemically administered PBAE nanoparticles will enable SR39 delivery to HCC tumors for safe and effective cancer killing and molecular genetic imaging. If successful, this interdisciplinary project will result in a novel precision approach to HCC treatment which may be adapted for clinical use.