The Tumor Microenvironment in Nanoparticle Delivery and Function

为了响应IRCN FOA，在此应用中，我们结合了二十年的经验， 通过分子和功能成像了解肿瘤微环境（TME），以及我们的经验 在开发治疗诊断纳米颗粒（NP），提供小干扰RNA（siRNA）， 了解TME在siRNA NP递送和功能中的作用。 siRNA已经成为癌症精确医学的有希望的候选者， 对于缺乏靶向治疗的三阴性乳腺癌（TNBC）等癌症非常重要。这里我们将 进行组合的体内PET-MR成像研究以关联siRNA NP递送，如通过PET成像检测的， 血管参数，酸性细胞外pH值（pHe）和细胞外基质（ECM）孔隙率，如通过 MRI以了解TME在siRNA NP递送和功能中的作用。我们选择的右旋糖酐NP是 生物相容性使其成为一个优秀的翻译候选者;我们选择用于递送的siRNA下调 胆碱激酶（Chk）是癌细胞中的重要靶点。Chk的下调导致总的 胆碱，可以用MR光谱成像（MRSI）成像，使我们能够将siRNA递送与 非侵入性功能。PET和MR也很容易翻译成人类。 我们将整合离体质谱成像（MSI），二次谐波发生（SHG）显微镜， 和免疫组化（IHC）的共定位肿瘤切片，以扩大我们的理解的变化， Chk siRNA介导的蛋白质组、脂质组和代谢组MSI，以及 用SHG显微镜和IHC观察在NP递送和分布中起作用ECM。这些研究报告将 用基因工程改造的人TNBC异种移植物进行， 因子（VEGF）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提供给联盟获奖者，并用于 目前的联盟网络，以建立互利的合作。这些研究有可能 为实现癌症的精确医疗提供未来的临床可转化应用。

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.