Intra-vital metabolic microscopy to reveal head and neck cancer radiation resistance mechanism in small animal models

头颈部鳞状细胞癌（HNSCC）的大多数死亡是由于放射治疗（RT）后肿瘤复发。超过75%的HNSCC患者接受放疗作为其治疗的一部分，其中超过50%的患者在放疗后有复发的风险。放疗耐药（RR）导致头颈部鳞状细胞癌（HNSCC）患者预后不良。RT治疗失败的原因是缺氧。然而，新的研究发现，仅通过rt诱导的再氧合率并不能区分原发性和复发性HNSCC肿瘤，因为一些复发性肿瘤在rt后也出现再氧合。r诱导的缺氧诱导因子-1- α (HIF-1α)的过度表达已被证明与rt失败的风险增加有关。HIF-1α调节许多生长因子，促进有氧糖酵解和血管生成。我们假设，rt诱导的HIF-1α表达和随后代谢/脉管系统的改变是HNSCC RR的基础。揭示逃避RT和复发的细胞的代谢特征，以及支持血管系统的作用，对于制定预防HNSCC复发和提高患者生存率的策略至关重要。然而，令人惊讶的是，很少有技术可以提供这些特征在体内的系统级视图。为了填补这些空白，我将建立一个便携式多参数显微镜，在体内测量小动物模型的代谢和脉管系统的主要轴。然后，我将利用这些平台研究辐射对HNSCC肿瘤的影响，并检验我们对HNSCC RR发展的假设。该技术填补了体外细胞研究和全身成像之间的重要空白，是代谢组学和免疫组织化学（IHC）的补充。我设想该系统将非常适合于研究患者来源的异种移植（PDX）和类器官模型中的肿瘤RR和复发，它可以忠实地概括患者肿瘤的许多微环境特征。该研究的成功完成将为将光学技术转化为PDX模型中患者来源的肿瘤系成像奠定基础，使我们能够确定复发的预测因素，并开发用于HNSCC的改进放射治疗（HIF-1抑制剂）。

Most deaths from head and neck squamous cell cancer (HNSCC) result from tumor recurrence following radiotherapy (RT). More than 75% of HNSCC patients receive RT as part of their care and over 50% of them are at risk for developing recurrence post RT. Radio-resistance (RR) leads to poor prognosis in head and neck squamous cell cancer (HNSCC) patients. The failure of RT has been attributed to hypoxia. However, new studies found that RT-induced re-oxygenation rates alone cannot distinguish primary from recurring HNSCC tumors, as some recurrent tumors also showed re-oxygenation after RT. Overexpression of RTinduced Hypoxia-Inducible Factor-1-alpha (HIF-1α) has been shown to be associated with an increased risk of failure of RT. HIF-1α is known to regulate many growth factors to promote aerobic glycolysis and angiogenesis. We hypothesize that RT-induced HIF-1α expression and subsequent alterations in metabolism/vasculature underlie HNSCC RR. Unraveling metabolic traits of cells that evade RT and recur, and the role of the supporting vasculature, is critical to developing strategies to prevent HNSCC recurrence and improve patient survival. However, there are surprisingly few techniques available to provide a systems level view of these hallmarks together in vivo. To fill these gaps, I will build a portable multi-parametric microscope to measure the major axes of metabolism and vasculature in small animal models in vivo. I will then use these platforms to study the effect of radiation on HNSCC tumors and test our hypothesis on HNSCC RR development. This technology fills an important gap between in vitro studies on cells and whole body imaging, and is complementary to metabolomics and immunohistochemistry (IHC). I envision that this system will be well suited to study tumor RR and recurrence in patient-derived xenograft (PDX) and organoid models, which can faithfully recapitulate many micro-environmental features of patient tumors. Successful completion of the proposed studies will set the foundation for translating the optical technology to image patient derived tumor lines in PDX models, allowing us identify predictors of recurrence and develop improved radiotherapeutics (HIF-1 inhibitors) for HNSCC.