Regulation of Targeted Therapeutic Response by the Immune Microenvironment in HNSCC

尽管优化了治疗方案，但头颈部鳞状细胞癌的5年生存率 （HNSCC）保持在50%左右。EGFR是受体酪氨酸激酶（RTK）网络的关键组分， 在HNSCC细胞系中作为非突变的“驱动”，并且是FDA批准的药物西妥昔单抗的靶点。 就个体而言，HNSCC患者对西妥昔单抗以及ERBB家族表现出广泛的应答程度- 靶向酪氨酸激酶抑制剂（TKI），如阿法替尼。重要的是，即使与化疗或 在放疗中，EGFR抑制剂不能消除100%的肿瘤细胞。这些耐药肿瘤细胞，称为 “残留病细胞”被认为是致命的耐药癌症最终产生的储存库。 以推动进步。作为支持，治疗诱导的肿瘤缩小程度与以下因素相关： 某些癌症的无进展生存期。因此，深化HNSCC对靶向药物的反应， 预测精确攻击残留疾病状态的基于机制的药剂组合将延长 无进展生存期和总生存期。 目前，肿瘤细胞持久性和治疗异质性的生物学机制- 在HNSCC患者中观察到的诱导的肿瘤反应是不明确的，突出了关键的知识差距。我们 初步数据表明用靶向EGFR或MEK抑制剂抑制EGFR-MEK-MAPK轴 在人和鼠HNSCC细胞系中，快速刺激先天性免疫应答，导致诱导 向肿瘤微环境（TME）中的免疫细胞以及抗原发出信号的趋化因子和细胞因子 呈递途径（MHC I类）。重要的是，效应T细胞和NK细胞的可变诱导 趋化因子、CXCL 10、促肿瘤细胞因子、TGFβ和IL 6以及I类MHC在肿瘤细胞内表达。 一组HNSCC细胞系，支持这种EGFR/MEK抑制剂内的内在异质性- 诱导的先天免疫反应指示直接但可变的免疫细胞参与治疗 反应 我们建议询问HNSCC残留疾病状态与患者标本，同基因小鼠， 肿瘤模型和人HNSCC细胞系作为描绘新的旁分泌途径的手段， 治疗诱导的癌细胞-TME串扰。这项提议将检验快速转录 靶向EGFR-MEK-MAPK轴抑制剂刺激的重编程诱导可变谱的抗- 以及与免疫微环境沟通的促肿瘤趋化因子和细胞因子， 直接参与治疗反应。此外，HNSCC患者的内在异质性 在这种先天反应的总体抗肿瘤与促肿瘤平衡中， 观察到的反应程度。成功完成这些研究可能是目前的重点 未被重视的免疫途径，用于未来基于机制的药物组合的合理靶向。 目的1：表征患者中早期EGFR/MEK介导的重编程和免疫细胞含量， 小鼠原位HNSCC肿瘤，并与治疗反应相关。这些研究将检验这一假设 更大程度的治疗反应与效应T细胞浸润增加有关， 髓样细胞含量以及增加的MHC I类表达。目的2：将小鼠HNSCC细胞系 在免疫活性和免疫缺陷宿主中原位繁殖，以测试特异性抗体的直接贡献。 免疫细胞群体对EGFR和MEK抑制剂治疗反应的影响。目标3：确定 EGFR/MEK受体在HNSCC细胞系中诱导的先天性免疫应答，并测试其在体内的作用。 治疗反应

Despite optimized therapeutic regimens, the 5-year survival rate for head and neck squamous cell carcinoma (HNSCC) remains around 50%. EGFR is a key component of a receptor tyrosine kinase (RTK) network that functions as a non-mutated “driver” in HNSCC cell lines and is the target for the FDA-approved agent, cetuximab. Individually, HNSCC patients exhibit wide-ranging extent of response to cetuximab as well as ERBB family- targeted tyrosine kinase inhibitors (TKIs) such as afatinib. Importantly, even in combination with chemo- or radiotherapy, EGFR inhibitors fail to eliminate 100% of tumor cells. These therapy-resistant tumor cells, termed “residual disease cells”, have been invoked as a reservoir from which lethal drug resistant cancers ultimately emerge to drive progression. In support, the extent of therapy-induced tumor shrinkage correlates with progression-free survival in some cancers. Thus, deepening the HNSCC response to targeted drugs through mechanism-based combinations of agents that precisely attack the residual disease state is predicted to extend progression-free and overall survival. At present, the biological mechanisms that underlie tumor cell persistence and the heterogeneity of therapy- induced tumor responses observed in HNSCC patients are ill-defined, highlighting a critical knowledge gap. Our preliminary data demonstrate that inhibition of the EGFR-MEK-MAPK axis with targeted EGFR or MEK inhibitors in human and murine HNSCC cell lines rapidly stimulates an innate immune response leading to induction of chemokines and cytokines that signal to immune cells in the tumor microenvironment (TME) as well as antigen presentation pathways (MHC class I). Importantly, variable induction of the effector T cell and NK cell chemoattractant, CXCL10, pro-tumorigenic cytokines, TGFβ and IL6, and MHC class I are observed within a panel of HNSCC cell lines, supporting the idea that intrinsic heterogeneity within this EGFR/MEK inhibitor- induced innate immune response instructs direct, yet variable immune cell participation in the therapeutic response. We propose to interrogate the HNSCC residual disease state with patient specimens, syngeneic murine tumor models and human HNSCC cell lines as a means for delineating novel paracrine pathways mediating therapy-induced cancer cell-TME cross-talk. This proposal will test the hypothesis that rapid transcriptional reprogramming stimulated by targeted EGFR-MEK-MAPK axis inhibitors induces a variable spectrum of anti- and pro-tumorigenic chemokines and cytokines that communicate with the immune microenvironment, leading to its direct participation in the therapeutic response. Moreover, intrinsic heterogeneity among HNSCC patients in the overall anti- vs. pro-tumorigenic balance of this innate response contributes to the observed variability in the extent of the observed responses. Successful completion of the studies may highlight presently unappreciated immune pathways for rational targeting with mechanism-based drug combinations in the future. Aim 1: Characterize early EGFR/MEK inhibitor-induced reprogramming and immune cell content in patient and murine orthotopic HNSCC tumors and associate with therapeutic response. The studies will test the hypothesis that greater degree of therapeutic response is linked to increased effector T cell infiltration and decreased myeloid cell content as well as increased MHC class I expression. Aim 2: Murine HNSCC cell lines will be propagated orthotopically in immune-competent and -deficient hosts to test the direct contributions of specific immune cell populations to the EGFR and MEK inhibitor therapeutic response. Aim 3: Define the mechanism of the EGFR/MEK inhibitor-induced innate immune response in HNSCC cell lines and the test the role in the in vivo therapeutic response.