Mechanisms and Therapeutic Targets of SCC Metastasis

鳞状细胞癌（SCC）起源于复层上皮，这是退伍军人中最相关的器官部位。 人群的皮肤和口腔，高暴露于紫外线照射和烟草致癌物使 SCC的总发病率和高发病率明显高于平民。SCC最坏的结果就是死亡 通过转移，最常见于肺。SCC死亡人数超过黑色素瘤死亡人数， SCC病例数。由于缺乏自发性SCC肺转移模型， SCC肺转移机制和治疗靶点。我们开发了几种基因工程 小鼠模型，将人SCC中常见的驱动突变靶向角蛋白K15+干细胞。这些 模型以不同的频率发生自发性肺SCC转移。连同它们的衍生细胞 细胞系，它们是研究不同免疫肿瘤中SCC肺转移机制的独特工具 微环境（TME）。我们已经表明，癌症干细胞（CSC）的亚群，即，赫司特 染料排除侧群（SP），具有转移的能力，这表明CSC的性质决定了 肺转移途径我们的初步数据显示，来源于肿瘤的癌相关成纤维细胞（CAF） 转移性SCC在体外增强CSC的扩增和侵袭，并在体内接种到肺中。此外，CAF 经历细胞外基质（ECM）蛋白的基因表达的独特变化，以及 SCC CAF与其他转移性癌症不同。最后，靶向骨髓细胞减少了SCC 转移综上所述，我们假设CSC的特性使它们倾向于通过血管传播 并在肺部存活另外，SCC-CAF串扰具有局部和系统效应，从而准备了用于测量的信号。 转移性TME和转移前（转移前）/转移性（SCC细胞接种后）小生境。使用我们 小鼠模型以及患者的SCC标本，拟议的研究将确定预后标志物， 高风险转移性SCC的治疗靶点，并开发将纳入 诊所在不久的将来目的1将评估与多能CSC特性相关的分子是否有助于 CSCs的侵袭和血管内渗。目标2将鉴定转移性SCC特异性CAF ECM 增强转移性CSC特性的特征和分子标记。目标3将确定系统性影响 在原发性SCC和转移前/转移小生境中建立转移性TME的CAF-SCC相互作用 在肺部。我们独特的小鼠模型系统和与人类SCC的跨物种比较，多重高 通量检测和创新方法将显著加快发现SCC转移 机制，同时测试治疗干预措施。

Squamous cell carcinomas (SCCs) arise from stratified epithelia, the most relevant organ sites in the veteran population are the skin and oral cavity where high exposure to UV irradiation and tobacco carcinogens make the total and high-risk SCCs significantly higher than the civilian population. SCC’s worst outcome is death through metastasis, most commonly in the lung. SCC deaths exceed melanoma deaths due to the high number of SCC cases. The lack of spontaneous SCC lung metastasis models has hindered identification of SCC lung metastasis mechanisms and therapeutic targets. We developed several genetically engineered mouse models that target driver mutations frequently found in human SCCs to keratin K15+ stem cells. These models develop spontaneous lung SCC metastasis with different frequencies. Together with their derived cell lines, they are unique tools to study mechanisms of SCC lung metastasis in different immune tumor microenvironments (TME). We have shown that a subpopulation of cancer stem cells (CSCs), i.e., the Hoechst dye excluding side population (SP), have the ability to metastasize, suggesting that CSC properties dictate the lung metastasis route. Our preliminary data revealed that cancer associated fibroblasts (CAFs) derived from metastatic SCCs enhanced CSC expansion and invasion in vitro and seeding to the lung in vivo. Further, CAFs undergo unique changes in gene expression of extracellular matrix (ECM) proteins, and candidate markers for SCC CAFs are distinctive from other metastatic cancers. Lastly, targeting myeloid cells reduced SCC metastasis. Taken together, we hypothesize that CSC properties predispose them to travel via blood vessels and survive in the lung. Additionally, SCC-CAF crosstalk has local and systemic effects preparing the metastatic TME and premetastatic (prior to metastasis)/metastatic (after SCC cell seeding) niche. Using our mouse models as well as patients’ SCC specimens, the proposed studies will identify prognostic markers and therapeutic targets for high risk metastatic SCCs and develop interventional therapies that will be brought into clinic in the near future. Aim 1 will assess if molecules associated with multipotent CSC properties contribute to CSCs invasion and intravasation to blood vessels. Aim 2 will identify metastatic SCC-specific CAF ECM signatures and molecular markers that enhance metastatic CSC properties. Aim 3 will identify systemic effects of CAF-SCC interactions that establish a metastatic TME in primary SCC and pre-metastatic/metastatic niche in the lung. Our unique mouse model systems and cross-species comparisons with human SCCs, multiple high throughput assays and innovative approaches will significantly accelerate discovery of SCC metastasis mechanisms and simultaneously test therapeutic interventions.