Imaging lysosomes to predict metastasis in breast cancer

描述（由申请人提供）： 溶酶体在乳腺癌的侵袭和转移中起主要作用，因为它们是蛋白酶路由、调节和分泌的关键介质。溶酶体含有多种蛋白酶，乳腺癌细胞利用这些蛋白酶通过细胞外基质侵入。因此，非侵入性成像的溶酶体可能提供一个创新的战略，预测和描绘的转移潜力的乳腺肿瘤。我们最近开发了新的方法来光学成像溶酶体在活的人乳腺癌细胞，并定量特定的溶酶体参数。这些方法现在使我们能够验证我们的假设，即溶酶体和由细胞骨架成分介导的溶酶体运输在乳腺癌侵袭和转移中起重要作用。我们的具体目标是：（1）确定乳腺癌细胞是否将溶酶体募集到其细胞表面以通过ECM侵入，从而促进胞吐或胞吞过程，或两者。(2)评估以缺氧和细胞外酸性为特征的肿瘤微环境对浸润乳腺癌细胞中溶酶体运输的影响，从而评价参与溶酶体运输的细胞骨架组分的作用。(3)开发并验证人乳腺肿瘤异种移植模型中溶酶体参数的体内光学成像。将采用非侵入性、最先进的细胞和体内光学成像，如共聚焦、全内反射和多光子荧光显微镜。一组代表不同阶段侵袭力和转移潜力的人乳腺癌细胞系将用于细胞研究和肿瘤异种移植小鼠模型。我们的研究计划将测试乳腺癌中的溶酶体成像是否可以预测这些肿瘤的转移潜力。破坏溶酶体运输可能被证明是有用的，治疗，以防止转移性疾病。

DESCRIPTION (provided by applicant): Lysosomes can play a major role in breast cancer invasion and metastasis, because they are a key mediator of protease routing, regulation, and secretion. Lysosomes contain diverse proteases that breast cancer cells utilize to invade through the extracellular matrix. Thus, non-invasive imaging of lysosomes may provide an innovative strategy for predicting and delineating the metastatic potential of breast tumors. We have recently developed novel methods to optically image lysosomes in living human breast cancer cells, and to quantitate specific lysosomal parameters. These methods now enable us to test our hypothesis that lysosomes, and lysosomal trafficking mediated by cytoskeletal components, plays an important role in breast cancer invasion and metastasis. Our specific aims are: (1) To determine whether breast cancer cells recruit lysosomes to their cell surface to invade through the ECM, thereby either facilitating exocytic or endocytic processes, or both. (2) To assess the influence of the tumor microenvironment, characterized by hypoxia and extracellular acidity, on lysosomal trafficking in invading breast cancer cells, thereby evaluating the role of cytoskeletal components involved in lysosomal trafficking. (3) To develop and validate in vivo optical imaging of lysosomal parameters in human breast tumor xenograft models. Non-invasive, state-of-the-art cellular and in vivo optical imaging, such as confocal, total internal reflection, and multiphoton fluorescence microscopy will be employed. A panel of human breast cancer cell lines representing different stages of invasiveness and metastatic potential will be utilized in cell studies and tumor xenograft mouse models. Our research proposal will test whether imaging lysosomes in breast cancers can predict the metastatic potential of these tumors. Disruption of lysosomal trafficking may prove useful, therapeutically, to prevent metastasic disease.