Multi-scale Molecular Imaging of the Degradome in Breast Tumors

描述（由申请人提供）：溶酶体是乳腺癌侵袭、转移和细胞外基质（ECM）重塑中最重要的细胞器之一，因为它们含有几种降解酶，可以影响ECM的完整性和结构。溶酶体在体内乳腺癌降解中的作用实际上尚未被探索，部分原因是由于缺乏可用于可视化溶酶体的无创成像能力。我们最近开发并验证了新型近红外荧光（NIRF）探针，用于细胞培养和体内肿瘤溶酶体的无创成像。使用这些探针获得的初步数据支持溶酶体在乳腺癌侵袭和转移中的重要性。因此，我们打算使用这些探针来了解和定义癌细胞中溶酶体对侵袭、转移和ECM重塑的影响。I型胶原（Col1）纤维是促进乳腺肿瘤形成、侵袭和转移的ECM的重要组成部分。在这项应用中，我们将进行多尺度的分子和功能成像研究，以表征原发肿瘤和转移性结节中的Col1纤维基质，以了解Col1纤维是如何被癌症降解形成的，以及这是如何促进侵袭和转移的。我们将使用创新的、临床可翻译的光学二次谐波产生（SHG）显微镜对Col1纤维进行显微成像，该显微镜可以检测Col1纤维的固有光信号。我们将利用溶酶体特异性NIRF探针IR-2在体内对乳腺肿瘤模型中的溶酶体进行成像。我们将利用MMPSense检测基质金属蛋白酶活性和ProSense检测组织蛋白酶活性，对体内蛋白酶活性进行光学成像。我们将利用多尺度光学成像方法，重点了解溶酶体在Aim 1中乳腺肿瘤体内侵袭和Aim 2中乳腺癌转移中的作用。在Aim 3中，我们将确定体内实体瘤和转移结节中溶酶体和溶酶体酶对Col1纤维结构和完整性的影响。这三个目标将为溶酶体和溶酶体酶在乳腺癌模型中整体降解中的作用提供新的见解。本研究将进一步加深我们对溶酶体在癌症侵袭、转移和Col1纤维重塑中的作用的理解，最终可能导致基于溶酶体的新型治疗策略来治疗癌症。了解溶酶体和溶酶体酶在侵袭、转移和Col1纤维重塑中的作用，可能会导致创新诊断成像技术的发展，无创检测溶酶体探针作为替代标志物来评估这些肿瘤的侵袭性、转移潜力和Col1纤维结构。

DESCRIPTION (provided by applicant): Lysosomes are one of the most important cellular organelles in breast cancer invasion, metastasis, and extracellular matrix (ECM) remodeling, because they contain several degradative enzymes that can influence the integrity and structure of the ECM. The roles of lysosomes in the breast cancer degradome in vivo are virtually unexplored, due, in part, to a lack of noninvasive imaging capabilities available to visualize lysosomes. We recently developed and validated novel near-infrared fluorescent (NIRF) probes for noninvasive imaging of lysosomes in cell culture and tumors in vivo. Preliminary data obtained using these probes support the importance of lysosomes in breast cancer invasion and metastasis. We therefore intend to use these probes to understand and define the influence of lysosomes in cancer cells on invasion, metastasis, and ECM remodeling. Collagen type I (Col1) fibers are an important component of the ECM that can facilitate breast tumor formation, invasion, and metastasis. In this application, we will perform multi-scale molecular and functional imaging studies to characterize the Col1 fiber matrix in primary tumors and metastatic nodules to understand how Col1 fibers are shaped by the cancer degradome, and how this promotes invasion and metastasis. We will microscopically image Col1 fibers using innovative and clinically translatable optical second harmonic generation (SHG) microscopy, which detects an intrinsic optical signal from Col1 fibers. We will utilize the lysosome-specific NIRF probe IR-2 to image lysosomes in breast tumor models in vivo. We will optically image protease activities in vivo using MMPSense to detect matrix metalloprotease activities and ProSense to detect cathepsin activities. We will focus on understanding the role of lysosomes in breast tumor invasion in vivo in Aim 1, and in breast cancer metastasis in Aim 2 using multi-scale optical imaging approaches. In Aim 3, we will determine the influence of lysosomes and lysosomal enzymes on Col1 fiber structure and integrity in solid tumors and metastatic nodules in vivo. These three Aims will provide novel insights into the role of lysosomes and lysosomal enzymes within the overall degradome in breast cancer models. The proposed research will further our understanding of the role of lysosomes in cancer invasion, metastasis, and Col1 fiber remodeling, which may eventually lead to novel lysosome-based therapeutic strategies to treat cancer. Understanding the role of lysosomes and lysosomal enzymes in invasion, metastasis, and Col1 fiber remodeling may lead to the development of innovative diagnostic imaging techniques that noninvasively detect lysosomal probes as surrogate markers to assess invasiveness, metastatic potential, and Col1 fiber structure in these tumors. PUBLIC HEALTH RELEVANCE: The proposed research will further our understanding of the importance of lysosomes within the breast cancer degradome, and their role in invasion, metastasis, and extracellular matrix remodeling. The resulting findings may lead to novel lysosome-based therapeutic strategies to treat breast cancer. Imaging the lysosomal compartment size with the near-infrared probe IR-2 may provide a surrogate marker of cancer aggressiveness.