Mechanisms of Dual Inhibition of TGFbeta/PD-L1 in HNSCC

摘要 鳞状细胞癌(SCC)占头颈部(HN)癌的90%以上。位於重型的HNSCCs 吸烟者对治疗的反应很差，在所有HNSCC中复发/复发率最高 病人。程序性死亡抑制剂-1(PD-1)已被FDA批准用于治疗复发/复发的HNSCC，但 仅对约25%的HNSCC有效，表明存在额外的免疫抑制/逃避机制。我们 据报道，转化生长因子-β-1(转化生长因子-β-1)是一种免疫抑制因子，在60%的烟草中含量升高。 关联的HNSCC。转化生长因子β1是肝非小细胞癌所特有的，可引起大多数肿瘤的过度炎症。 渗入的白细胞是髓系细胞。开发新的治疗干预措施，有效地针对这些 肿瘤微环境(TME)特征因缺乏转移的HNSCC模型而受阻 有免疫能力背景的潜力。该应用程序使用新的治疗剂来针对这两个 PD-L1和转化生长因子β在人非小细胞肺癌及其转移中的作用，并分析其可能的机制。我们已经创建了一个 烟草相关HNSCCs中经常缺失的肿瘤抑制因子Smad4缺失的小鼠模型 (Smad4-/-)。Smad4缺失导致鳞癌和转移，代偿性转化生长因子β1 生产过剩。初步数据显示，Smad4-/-SCCs也过表达PD-L1和短期转化生长因子β 抑制使SCCs对抗PD-L1增敏。此外，在鳞癌被根除的小鼠中，重新移植相同的鳞癌 细胞系未能启动新的肿瘤，提示记忆T细胞依赖的抗肿瘤反应。转化生长因子β 抑制也减少了免疫受损小鼠的鳞状细胞癌肺转移。总而言之，我们假设 减轻转化生长因子β诱导的Smad4突变体的免疫抑制和炎症反应 HNSCs使免疫治疗更加有效，因此双重的转化生长因子β/PD-L1抑制消除了这些 HNSCCs通过T细胞依赖和非依赖机制。目标1将进行实验 新型转化生长因子β/PD-L1抑制剂对遗传性小鼠模型和移植人类的治疗作用 HNSCCs确定Smad4缺失和转化生长因子β1过表达是否可预测转化生长因子β/PD-L1的治疗反应 免疫活性状态和免疫功能受损状态下HNSCCs的双重抑制。目标2将评估T细胞- 转化生长因子β抑制对抗PD-L1介导的鳞癌增敏或协同作用的依赖机制 根除，利用AIM 1中产生的肿瘤和患者HNSCC样本来检查Smad4丢失和 转化生长因子β/PD-L1水平与免疫抑制T细胞谱相关。AIM 3将使用在AIM中产生的肿瘤 1评估转化生长因子β/PD-L1抑制的髓系细胞依赖的靶向效应是否有助于治疗 检测Smad4缺失和转化生长因子β/PD-L1在肝细胞癌转移和转移中的作用 水平与髓系细胞和相关分子标记物的增加有关。这些研究将导致 复发率和转移率高的HNSCC患者的新治疗策略。此外， 机制研究将为未来的生物标记物驱动的选择提供新的见解，用于未来的临床试验 转化生长因子β/PD-L1双抑制在非小细胞肺癌中的作用

SUMMARY Squamous cell carcinoma (SCC) accounts for over 90% of head and neck (HN) cancer. HNSCCs in heavy smokers respond poorly to therapies and have the highest rate of relapse/recurrence among all HNSCC patients. Inhibitors of programmed death-1 (PD-1) are FDA approved to treat relapsed/recurrent HNSCCs, but are only effective in ~25% of HNSCCs, indicating additional immune suppressive/evasion mechanisms. We reported that transforming growth factor-β1 (TGFβ1), an immune suppressor, is elevated in >60% of tobacco- associated HNSCCs. Unique to HNSCC, TGFβ1 causes excessive inflammation with the majority of tumor infiltrating leukocytes being myeloid cells. Developing new therapeutic interventions that effectively target these tumor microenvironment (TME) characteristics is hindered by a dearth of HNSCC models with metastatic potential in an immune competent background. This application employs new therapeutic agents to target both PD-L1 and TGFβ in HNSCC and metastasis, and analyze the underlying mechanisms. We have created a mouse model in which Smad4, a tumor suppressor frequently lost in tobacco-associated HNSCCs, is deleted (Smad4-/-) in head and neck epithelia. Smad4 loss causes SCC and metastasis, and compensatory TGFβ1 overproduction. Preliminary data revealed that Smad4-/- SCCs also overexpress PD-L1 and short-term TGFβ inhibition sensitized SCCs to anti-PD-L1. Further, in mice with SCC eradicated, re-transplanting the same SCC cell line failed to initiate new tumors, suggesting a memory T cell-dependent anti-tumor response. TGFβ inhibition also reduced SCC lung metastases in immune compromised mice. Taken together, we hypothesize that attenuating a TGFβ-induced immune suppressive and inflammatory TME in Smad4 mutant HNSCCs makes immunotherapy more effective, thus dual TGFβ/PD-L1 inhibition eradicates these HNSCCs via T-cell-dependent and -independent mechanisms. Aim 1 will perform experimental therapeutics using novel TGFβ/PD-L1 inhibitor drugs on genetic mouse models and transplanted human HNSCCs to determine if Smad4 loss and TGFβ1 overexpression predict therapeutic response to TGFβ/PD-L1 dual inhibition in HNSCCs in immune competent and compromised conditions. Aim 2 will assess T cell- dependent mechanisms of TGFβ inhibition on sensitizing or synergizing with anti-PD-L1-mediated SCC eradication, utilizing tumors generated in Aim 1 and patient HNSCC specimens to examine if Smad4 loss and TGFβ/PD-L1 levels correlate with immune suppressive T cell profiles. Aim 3 will use tumors generated in Aim 1 to assess if myeloid cell-dependent targeting effects of TGFβ/PD-L1 inhibition contribute to therapeutic efficacy in HNSCC and metastasis, and patient HNSCC specimens to examine if Smad4 loss and TGFβ/PD-L1 levels correlate with increased myeloid cells and associated molecular markers. These studies will lead to a novel therapeutic strategy for HNSCC patients with high rates of recurrence and metastasis. Additionally, the mechanistic studies will offer novel insights into future biomarker-driven selection for future clinical trials of TGFβ/PD-L1 dual inhibition in HNSCC patients.