Developing Nanotechnology to Target HMGA1 in Pancreatic Cancer

描述(申请人提供)：这项提案的主要目标是开发和测试创新的“纳米颗粒”，以便在胰腺癌的临床前模型中系统地提供新的治疗方法(短发夹或shRNA)。胰腺导管腺癌(PDAC)是一种高致命性肿瘤，每年在全球范围内造成15万人死亡。大多数患者患有无法手术的转移性疾病，目前还没有有效的治疗方法。因此，迫切需要研究确定如何阻断PDAC的转移进展。我们正在研究导致PDAC肿瘤进展的分子途径。我们的重点是HMGA1癌基因，它编码HMGA1a和HMGA1b染色质重塑蛋白。HMGA1蛋白通过改变染色质结构来调节基因表达。我的实验室是第一个发现HMGA1在培养细胞和转基因小鼠中作为一种有效的癌基因发挥作用的实验室。我们还发现，抑制HMGA1的表达会阻止致癌和癌症干细胞的特性。我们小组和其他人最近发表的研究表明，HMGA1在90%的原发人类PDAC中过表达，在侵袭性、转移性肿瘤中表达最高，但在前驱病变或正常胰腺中没有表达。此外，我们还发现HMGA1蛋白水平与分化不良和生存率下降呈正相关。HMGA1的敲除可以阻止多种致癌和干细胞特性，包括锚定非依赖性细胞生长、迁移、侵袭、体外三维球体形成和PDAC小鼠模型中的转移进展。这些发现表明，HMGA1促进了PDAC中的肿瘤进展。引人注目的是，我们最近的研究表明，通过下调干细胞中重要的转录网络，用shRNA敲除HMGA1可以将癌细胞从高侵袭性的间充质样细胞重新编程为非侵袭性的上皮样细胞 细胞和肿瘤进展。HMGA1基因的敲除也提高了对细胞毒治疗的敏感性。我们的合作研究人员Hanes博士和Maitra博士最近开创了一种新的方法，通过在临床前模型中有效和持续地改变基因表达，系统地传递质粒纳米粒(NPs)。基于这些令人兴奋的结果，我们假设：1)HMGA1推动PDAC中的肿瘤进展，并可作为治疗的靶点。ShRNA NPs将阻断HMGA1的表达，并将PDAC细胞重新编程为对治疗有反应的侵袭性较弱的细胞。在这里，我们建议使用我们独特的资源和专业知识来验证这些假设，具体目标如下：1)为了确定在我们的临床前模型中，HMGA1的可诱导shRNA是否将PDAC细胞重新编程为非侵入性、治疗敏感的细胞，以及。开发NP技术，在PDAC的临床前模型中传递HMGA1 shRNA。我们将使用我们的NPs来测试shRNA的传递，这些NPs已经通过改变直径、形状、脂质含量和其他生物物理性质来优化传递和效率。如果成功，我们的研究将为PDAC的治疗提供一个新的范例，并改善患者的预后。

DESCRIPTION (provided by applicant): The primary goal of this proposal is to develop and test innovative "nanoparticles" to systemically deliver novel therapy (short hairpin or shRNA) in preclinical models for pancreatic cancer. Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors accounting for >150,000 deaths worldwide each year. Most patients present with inoperable, metastatic disease for which there are no effective therapies. Thus, research is urgently needed to determine how to block metastatic progression in PDACs. We are studying the molecular pathways that lead to tumor progression in PDAC. Our focus is the HMGA1 oncogene, which encodes the HMGA1a and HMGA1b chromatin remodeling proteins. HMGA1 proteins regulate gene expression by altering chromatin structure. My laboratory was the first to discover that HMGA1 functions as a potent oncogene in cultured cells and transgenic mice. We also found that inhibiting HMGA1 expression blocks oncogenic and cancer stem cell properties. Recently published studies from our group and others demonstrate that HMGA1 is overexpressed in >90% of primary, human PDACs, with highest levels in invasive, metastatic tumors, but no expression in precursor lesions or normal pancreas. Moreover, we found that HMGA1 protein levels are positively correlated with poor differentiation status and decreased survival. Knock-down of HMGA1 blocks multiple oncogenic and stem cell properties, including anchorage-independent cell growth, migration, invasion, 3-dimensional sphere formation in vitro and metastatic progression in murine models of PDAC. These findings indicate that HMGA1 promotes tumor progression in PDAC. Strikingly, our recent studies show that knock-down of HMGA1 with shRNA reprograms cancer cell lines from highly invasive, mesenchymal-like cells to noninvasive, epithelial-like cells by down-regulating transcriptional networks important in stem cells and tumor progression. Knock-down of HMGA1 also enhances sensitivity to cytotoxic therapy. Our co-investigators, Drs. Hanes and Maitra, have recently pioneered novel approaches to systemically deliver plasmid nanoparticles (NPs) with effective and sustained changes in gene expression in preclinical models. Based on these exciting results, we hypothesize that: 1.) HMGA1 drives tumor progression in PDAC and could serve as a target in therapy, and, 2.) shRNA NPs will block HMGA1 expression and reprogram PDAC cells into less aggressive cells that respond to therapy. Here, we propose to test these hypotheses using our unique resources and expertise with the following Specific Aims: 1.) To determine if inducible shRNA to HMGA1 reprograms PDAC cells into noninvasive, therapy-responsive cells in our preclinical models, and, 2.) To develop NP technology to deliver HMGA1 shRNA in preclinical models of PDAC. We will test shRNA delivery using our NPs that have been optimized for delivery and efficiency by altering diameter, shape, lipid content, and other biophysical properties. If successful, our studies should provide a new paradigm for the treatment of PDAC and improve outcomes for patients.