Imaging hypoxia-driven signaling pathways in the breast tumor microenvironment

描述（由申请人提供）：肿瘤缺氧与肿瘤进展、更高的转移扩散风险和对治疗的耐药性相关，因此已成为肿瘤生理学和癌症治疗的核心问题。迄今为止，对肿瘤缺氧影响的分子途径知之甚少，最终导致肿瘤预后差、治疗效果差的灾难性临床效果。缺氧诱导因子11 （hypoxia -inducible factor 11, HIF-11）在低氧条件下水平升高，通过影响其他生物分子水平在肿瘤缺氧中发挥重要作用。由于目前对肿瘤缺氧的关键生物分子知之甚少，我们将寻求迄今为止在乳腺肿瘤缺氧区域增加或减少的未知分子。我们将使用一个独特的模型系统来研究缺氧，该系统由人类乳腺癌细胞系和在免疫受损动物中生长的相应肿瘤模型组成，这些模型经过基因工程改造，含有内置的缺氧检测器。这种检测器将增加的HIF-11的自然缺氧反应耦合到可通过光学成像检测到的荧光标记物的产生。我们将把光学缺氧检测与体内磁共振光谱成像（MRSI）、尖端质谱成像（MSI）应用和靶向蛋白质组学策略结合起来。在我们的第一个特定目标中，我们将发现，识别和验证由于乳腺癌细胞培养物中的缺氧而减少或增加的生物分子。我们将比较三种在实验室缺氧条件下具有不同程度侵袭性和转移潜力的人类乳腺细胞系。在我们的第二个具体目标中，我们将在含有内置缺氧检测器的相同乳腺癌细胞系生长的实际乳腺肿瘤模型中进行平行研究。我们将使用与细胞系相同的基于ms的蛋白质组学方法分析这些乳腺肿瘤中的缺氧区。在第三个具体目标中，我们将使用多模态3D分子成像方法评估最初在目标1和2中发现的与缺氧相关的生物分子，该方法将结合体内核磁共振成像、光学成像和MSI方法。将获得含有内置缺氧检测器的相同乳腺肿瘤模型的MRS，光学和MS图像，这将使我们能够评估缺氧，已知缺氧标记分子和我们新发现的缺氧相关分子之间的空间关系。我们的研究将有助于更好地理解乳腺肿瘤中缺氧引发的分子途径。拟议的研究可能最终转化为新的乳腺癌治疗方法，用于肿瘤中有缺氧区域的患者。未来的研究可以探索将这些新发现的低氧相关分子作为治疗肿瘤缺氧的靶点的可能性，并有望改善乳腺癌低氧肿瘤患者的治疗效果。公共卫生相关性：缺氧使乳腺肿瘤具有侵袭性、转移性，并对放化疗产生耐药性。迄今为止，肿瘤缺氧的关键分子，如缺氧诱导因子11 （HIF-11）被发现的很少。发现和验证相关的低氧驱动通路，这可能赋予低氧肿瘤放射和化疗耐药和肿瘤侵袭性，对于克服乳腺肿瘤低氧的这些有害影响至关重要。在我们的应用中，我们的目标是阐明在实体乳腺肿瘤的异质性缺氧区域产生的迄今为止未知的分子途径。这些与低氧相关的生物分子可能在未来为创新的低氧靶向乳腺癌治疗提供新的分子靶点。

DESCRIPTION (provided by applicant): Tumor hypoxia has been associated with tumor progression, a higher risk of metastatic spread, and resistance to therapy, and has thus become a central issue in tumor physiology and cancer treatment. To date, very little is known about the molecular pathways that are affected by tumor hypoxia, and which eventually cause the disastrous clinical effects of poor cancer prognosis and poor treatment outcome. Hypoxia-inducible factor 11 (HIF-11), whose levels increase under hypoxic conditions, plays an important role in tumor hypoxia as it affects the levels of other biomolecules. Because currently little is known about the key biomolecules in tumor hypoxia, we will seek to identify to date unknown molecules that are increased or decreased in hypoxic regions in breast tumors. We will use a unique model system to study hypoxia, which consists of human breast cancer cell lines and the corresponding tumor models grown in immune-compromised animals that were genetically engineered to contain a built-in hypoxia detector . This detector couples the natural hypoxia response of increased HIF-11 to the production of a fluorescent marker that can be detected by optical imaging. We will combine optical hypoxia detection with in vivo magnetic resonance spectroscopic imaging (MRSI), cutting- edge mass spectrometry imaging (MSI) applications, and targeted proteomics strategies. In our first specific aim, we will discover, identify, and validate biomolecules that are decreased or increased due to hypoxia in breast cancer cell cultures. We will compare three human breast cell lines representing different degrees of aggressiveness and metastatic potential that have been made hypoxic in the laboratory. In our second specific aim, we will carry out parallel studies in actual breast tumor models grown from the same breast cancer cells lines, which contain the built-in hypoxia detector . We will analyze the hypoxic regions in these breast tumors using the same MS-based proteomics approach as in the cell lines. In the third specific aim, we will evaluate the hypoxia-related biomolecules initially identified in Aims 1 and 2 using a multimodal 3D molecular imaging approach, which will combine in vivo MRSI, optical imaging, and MSI methods. MRS, optical, and MS images will be acquired of the same breast tumor models containing the built-in hypoxia detector , which will enable us to assess the spatial relationship between hypoxia, already known hypoxia marker molecules, and our newly identified hypoxia-related molecules. Our studies will lead to a better understanding of the molecular pathways that are triggered by hypoxia in breast tumors. The proposed studies may eventually translate into new breast cancer therapies for patients that have hypoxic regions in their tumors. Future studies can explore possibilities to use these newly discovered hypoxia-related molecules as targets for treating tumor hypoxia, and hopefully improve the treatment outcome of cancer patients with hypoxic breast tumors. PUBLIC HEALTH RELEVANCE: Hypoxia renders breast tumors aggressive, metastatic, and resistant to treatment with radio- and chemotherapy. To date, very few molecular key players in tumor hypoxia, such as for example hypoxia inducible factor 11 (HIF-11), have been discovered. Discovering and validating relevant hypoxia-driven pathways, which potentially confer radio- and chemoresistance and tumor aggressiveness in hypoxic tumors, will be of crucial importance to overcome these detrimental effects of breast tumor hypoxia. In our application, we aim to elucidate such to date unknown molecular pathways that are produced in the heterogeneous hypoxic regions of solid breast tumors. Such hypoxia-related biomolecules may, in the future, provide novel molecular targets for innovative hypoxia-targeted breast cancer therapies.