In vivo monitoring of tumor microenvironment regulation by macrophages

 描述(申请人提供)：本项目的总体目标是证明肿瘤微环境和巨噬细胞之间的双向相互作用在肿瘤进展和治疗效果中起重要作用的假设。这一假说是在活组织水平上专门提出的，因此将使用创新的基于电子顺磁共振(EPR)的多功能方法在体内进行测试。这些方法将被用来在体内关联巨噬细胞和巨噬细胞特异性的HIF-1a和HIF-2a在调节肿瘤缺氧、细胞外pH(Phe)、氧化还原和谷胱甘肽(GSH)中的作用；以及这些因素的缺失如何影响PYMT小鼠乳腺癌模型的临床相关抗癌治疗策略。其具体目标是：(SA1)优化磁共振方法，用于体内多功能肿瘤组织参数的监测：pH、氧、氧化还原和GSH。新的顺磁探针和技术将被优化为在肿瘤组织中的多功能应用，重点是应用于小鼠的PYMT乳腺肿瘤。(SA2)探讨巨噬细胞在调节乳腺癌肿瘤微环境中的作用。我们假设巨噬细胞显著影响乳腺癌中的氧分压、酸中毒、氧化还原和细胞内GSH(肿瘤微环境的EPR信号)，尽管巨噬细胞HIF-1a和HIF-2a都是低氧诱导蛋白，但在调节肿瘤微环境中的这些参数方面，巨噬细胞HIF-1a和HIF-2a具有不同和相反的作用，我们可以检测到含有巨噬细胞消融或HIF-1a或HIF-2a缺失的转基因小鼠之间相应EPR信号的变化。(SA3)研究巨噬细胞调节的肿瘤微环境及其在乳腺癌化疗疗效中的作用。我们将检验这样一种假设，即肿瘤的PO2、Phe、氧化还原和GSH共同形成的肿瘤微环境特征可以预测标准化疗的成功程度，而巨噬细胞是肿瘤微环境调节的关键。具体地说，我们将测试肿瘤巨噬细胞极性(M1/M2)的优势是否会调节肿瘤微环境和标准化疗药物(如多西紫杉醇)的疗效，以及巨噬细胞HIF-1a缺失是否会增加多西紫杉醇的有效性。综上所述，这些结果可能为肿瘤微环境和巨噬细胞调节临床相关抗癌治疗的疗效提供新的见解。

 DESCRIPTION (provided by applicant): The overall goal of this project is to prove the hypothesis that bi-directional interaction between tumor microenvironment and macrophages plays significant role in tumor progression and therapy efficacy. This hypothesis is specifically formulated at the level of living tissue and therefore will be tested in vivo using innovative electron paramagnetic resonance (EPR)-based multifunctional approaches. These approaches will be used to correlate, in vivo, the role of macrophages and macrophage-specific HIF-1a and HIF-2a in the regulation of tumor hypoxia, extracellular pH (pHe), redox and glutathione (GSH); and how deletion of these factors affects clinically-relevant anti-cancer treatment strategies in the PyMT mouse model of breast cancer. The specific aims are: (SA1) To optimize magnetic resonance modalities for in vivo multifunctional monitoring of tumor tissue parameters: pH, oxygen, redox and GSH. Novel paramagnetic probes and techniques will be optimized for multi-functional application in tumor tissue with the focus on application to the PyMT mammary tumors in mice. (SA2) To investigate the role of macrophages in regulating the tumor microenvironment in breast cancer. We hypothesize that macrophages significantly affect oxygen tension, acidosis, redox and intracellular GSH (EPR signature of tumor microenvironment) in breast cancer, and that despite both being hypoxia-inducible proteins, macrophage HIF-1a and HIF-2a have disparate and opposing roles in the regulation of the these parameters in the tumor microenvironment, and that we can detect changes in corresponding EPR signature between transgenic mice containing the macrophage ablation or HIF-1a or HIF- 2a deletions. (SA3) To investigate macrophage-regulated tumor microenvironment and their role in chemotherapy efficacy in breast cancer. We will test the hypothesis that tumor pO2, pHe, redox and GSH all combine to form a tumor microenvironment profile that can predict levels of success for standard chemotherapies, and macrophages are a lynchpin in tumor microenvironment regulation. Specifically, we will test whether predominance in tumor macrophage polarity (M1/M2) will regulate a tumor microenvironment and the efficacy of standard chemotherapies, such as docetaxel, and whether macrophage HIF-1a deletion will increase docetaxel effectiveness. In summary, the results may provide new insight into the tumor microenvironment and macrophage regulation of efficacy of clinically-relevant anti-cancer therapies.