The Tumor Microenvironment in Nanoparticle Delivery and Function

为了回应这个IRCN FOA，在这个申请中，我们结合了我们二十年来在 用分子和功能成像了解肿瘤微环境(TME)，以及我们的经验 十年来一直在开发能够传递小干扰RNA(SiRNA)的抗癌纳米颗粒(NPs)，以 了解TME在siRNA NP递送和功能中的作用。 SiRNA已经成为治疗癌症的精准医学的有前途的候选者，这种癌症变得非常重要 对于三重阴性乳腺癌(TNBC)等缺乏针对性治疗的癌症来说，这一点很重要。在这里，我们将 进行联合体内PET-MR成像研究以关联由PET成像检测到的siRNA NP递送， 对血管参数、酸性细胞外pH(Phe)和细胞外基质(ECM)孔隙率的影响 MRI以了解TME在siRNA NP递送和功能中的作用。我们选择的葡聚糖NP是 生物相容使其成为极好的翻译候选者；我们选择用于传递的siRNA下调了 胆碱激酶(Chk)，癌细胞的一个重要靶点。CHK的下调导致总量的下降 可以用磁共振光谱成像(MRSI)成像的胆碱，使我们能够将siRNA传递与 起到非侵入性的作用。PET和MR也很容易翻译给人类。 我们将把体外质谱学成像(MSI)、二次谐波产生(SHG)显微镜、 和免疫组织化学(IHC)共同定位的肿瘤切片，以扩大我们对变化的理解 由Chk siRNA介导的MSI对蛋白质组、脂体和代谢组的影响及其特性 应用SHG显微镜和IHC观察在NP的传递和分布中起作用的ECM。这些研究将是 使用基因工程的人TNBC异种移植过表达血管内皮细胞生长 因子(血管内皮生长因子)或报告缺氧。试剂、资源、肿瘤模型和成像技术 通过此应用程序开发的应用程序将可供联盟获奖者和外部协作使用 目前的联盟网络，以建立互利合作。这些研究有可能 在实现癌症的精准医学方面提供未来临床可翻译的应用。

In response to this IRCN FOA, in this application we have combined our experience of two decades in understanding the tumor microenvironment (TME) with molecular and functional imaging, and our experience of a decade in developing theranostic nanoparticles (NPs) that deliver small interfering RNA (siRNA), to understand the role of TME in siRNA NP delivery and function. siRNA have emerged as promising candidates for precision medicine in cancer that becomes significantly important for cancers such as triple negative breast cancer (TNBC) that lack targeted treatments. Here we will perform combined in vivo PET-MR imaging studies to relate siRNA NP delivery, as detected by PET imaging, to vascular parameters, acidic extracellular pH (pHe), and extracellular matrix (ECM) porosity as detected by MRI to understand the role of the TME in siRNA NP delivery and function. The dextran NP we selected is biocompatible making it an excellent translational candidate; the siRNA we selected for delivery downregulates choline kinase (Chk), an important target in cancer cells. Downregulation of Chk results in a decrease of total choline that can be imaged with MR spectroscopic imaging (MRSI), allowing us to relate siRNA delivery to function noninvasively. Both PET and MR are also easily translatable to humans. We will integrate ex vivo mass spectrometry imaging (MSI), second harmonic generation (SHG) microscopy, and immunohistochemistry (IHC) of co-localized tumor sections to expand our understanding of the changes mediated by the Chk siRNA on the proteome, lipidome and metabolome with MSI, and of the characteristics of the ECM that play a role in NP delivery and distribution with SHG microscopy and IHC. These studies will be performed with human TNBC xenografts genetically engineered to overexpress vascular endothelial growth factor (VEGF) or to report on hypoxia. The reagents, resources, tumor models and imaging technologies developed through this application will be available to the Alliance awardees and for collaborations outside of the current Alliance network to establish mutually beneficial collaborations. These studies have the potential to provide future clinically translatable applications in achieving precision medicine of cancer.