TGF-betas in breast cancer progression

在2017财年，我们继续使用我们开发的一种新颖的功能成像方法来解决tgf - β在调节癌症干细胞（CSC）室中的作用，该方法允许实时和原位可视化这种少数细胞群。我们基于慢病毒的CSC报告子使用合成启动子，其中荧光蛋白的表达由干细胞主转录因子Oct4和Sox2驱动。使用这种方法，我们已经开发了允许在2D和3D培养系统中扩展单个CSC的细胞命运映射的方法，并且我们与阿尔伯特爱因斯坦医学院的John Condeelis博士的实验室正在合作，对原发肿瘤和肺转移部位的CSC群体进行活体成像。我们对最初的报告器设计进行了各种修改，以产生一个改进的报告器，进一步优化了活体成像，并带有组织病理学的免疫染色标签。我们已经开始研究tgf - β在乳腺癌模型系统中对CSC生物学的影响，这些模型系统显示出对tgf - β的肿瘤抑制或促进展反应。重要的是，我们已经证明，在体内使用中和性抗tgf - β抗体治疗会增加两种异种移植乳腺癌模型中的肿瘤干细胞数量，其中tgf - β具有肿瘤抑制作用，而在tgf - β具有促进展作用的模型中则会减少肿瘤干细胞数量。了解tgf - β诱导癌症干细胞数量增加或减少的详细机制的研究正在进行中。我们正在使用包括RNA-Seq和ATAC-Seq在内的综合基因组方法来解决tgf - β在疾病过程的早期和晚期对CSC和非CSC室的差异效应的分子机制。了解CSCs在体内是如何被调节的，对于开发更有效的癌症治疗方法至关重要，因为这些细胞对现有的治疗方法有很大的抵抗力。

In FY17, we have continued to address the role of TGF-beta in regulating the cancer stem cell (CSC) compartment using a novel functional imaging approach that we developed to allow visualization of this minority cell population in real time and in situ. Our lentiviral-based CSC reporter uses a synthetic promoter in which expression of a fluorescent protein is driven by the stem cell master transcription factors Oct4 and Sox2. Using this approach, we have developed methods that allow extended cell fate mapping of individual CSCs in 2D and 3D culture systems and we have an ongoing collaboration with the lab of Dr. John Condeelis at the Albert Einstein College of Medicine to perform intravital imaging of the CSC population in the primary tumor and at the lung metastatic site. We have made various modifications to our original reporter design to generate an improved reporter that is further optimized for intravital imaging and with an immunostainable tag for histopathology. We have begun to address the effect of TGF-beta on CSC biology in breast cancer model systems that show either tumor suppressor or pro-progression responses to TGF-beta. Importantly, we have shown that treatment with neutralizing anti-TGF-beta antibodies in vivo will increase the cancer stem cell population in two xenograft breast cancer models in which TGF-beta functions as a tumor suppressor, while decreasing it in a model in which TGF-beta has pro-progression effects. Studies to understand the detailed mechanisms by which TGF-beta induces either an expansion or a reduction in the cancer stem cell population are ongoing. We are employing integrated genomic approaches including RNA-Seq and ATAC-Seq to address the molecular mechanisms underlying differential effects of TGF-beta on CSC and non-CSC compartments at early and late stages of the disease process. Understanding how CSCs are regulated in vivo will be critical to development of more effective cancer therapies, as these cells are largely resistant to existing therapeutic approaches.