Role of the AHR pathway in UV-induced initiation and progression of melanoma and in resistance to therapy

黑色素瘤是最致命的皮肤癌类型，占全球癌症病例的近2%，由于娱乐性紫外线暴露的持续趋势，发病率不断增加。芳香烃受体（AHR）是一种配体结合转录因子，属于碱性螺旋-环-螺旋Per-ARNT-Sim家族，最初被描述为二恶英TCDD的受体，并已被证明介导环境污染物的解毒。最近，已经发现了许多生理和内源性配体，沿着越来越多的证据表明AHR在细胞增殖、分化和炎症反应中的生理作用。紫外线已经显示出产生高亲和力AHR激动剂FICZ，其促进皮肤晒黑作为对紫外线的保护反应。然而，在癌细胞中，AHR活化促进肿瘤进展。目前的项目是基于这样的假设，即AHR信号在生理环境中促进对UV照射的保护性黑素细胞反应，而在病理环境中，AHR信号增强恶性转化以及转移进展，并损害T细胞定向免疫疗法的功效。在该项目的第一个工作包中，我们将使用黑素细胞特异性的条件性AHR敲除小鼠来表征AHR信号传导对黑素细胞对紫外线的反应的影响。此外，我们还将分析AHR信号传导在UV诱导的肿瘤发展和进展中的作用，通过利用Hgf-Cdk 4黑色素瘤模型与黑素细胞特异性AHR敲除小鼠杂交。在第二个工作包中，我们将评估AHR信号在免疫治疗中的作用。为此，我们将使用具有和不具有CRISPR介导的AHR敲除的可移植黑色素瘤细胞系HCmel 12，并进行过继性T细胞转移。此外，我们还将结合联合收割机过继细胞转移疗法与药物AHR抑制在小鼠移植HCmel 12黑色素瘤细胞，以评估未来的前景治疗AHR抑制在man. In第三个工作包，我们将在体外黑色素细胞和黑色素瘤细胞的AHR信号动力学的特点。随后，我们试图分析AHR信号对炎症诱导的黑色素瘤细胞可塑性的影响，并揭示其潜在的分子机制。在最后的工作包中，我们将通过单细胞RNA测序分析AHR信号对黑色素瘤细胞转录可塑性动态的影响，以响应炎症和治疗刺激。此外，我们还将描述AHR信号在UVB照射后皮肤黑素细胞和黑色素瘤细胞分化轨迹上的特征。我们期望从该项目中获得的见解将为将来在黑色素瘤治疗中调节AHR信号传导提供理论基础。

Melanoma, the most lethal type of skin cancer, accounts for almost 2% of cancer cases worldwide, with an increasing incidence due to the unbroken trend of recreational UV exposure. The aryl hydrocarbon receptor (AHR), a ligand binding transcription factor of the basic helix-loop-helix Per-ARNT-Sim family, was initially described as the receptor for the dioxin TCDD and has been shown to mediate the detoxification of environmental pollutants. More recently, a multitude of physiological and endogenous ligands have been discovered, along with increasing evidence of physiological roles of AHR in cell proliferation, differentiation and inflammatory responses. UV light has been shown to generate the high affinity AHR agonist FICZ that promotes skin tanning as a protective response against UV. However, in cancer cells AHR activation promotes tumor progression. The current project is based on the hypothesis that AHR signaling promotes protective melanocyte responses to UV irradiation in physiological settings, whereas in pathologic settings, AHR signaling enhances malignant transformation as well as metastatic progression and impairs the efficacy of T cell directed immunotherapies. In the first work package of the project, we will use melanocyte-specific, conditional AHR knockout mice to characterize the impact of AHR signaling on the response of melanocytes to UV light. Additionally, we will also analyze the role of AHR signaling on UV-induced tumor development and progression by utilizing the Hgf-Cdk4 melanoma model crossed with the melanocyte-specific AHR knockout mice. In the second work package, we will assess the role of AHR signaling on immunotherapy. For this, we will use our transplantable melanoma cell line HCmel12 with and without a CRISPR mediated AHR knockout and perform adoptive T-cell transfer. Furthermore, we will also combine adoptive cell transfer therapies with pharmacological AHR inhibition in mice transplanted with HCmel12 melanoma cells to assess the future prospect of therapeutic AHR inhibition in man. In the third work package, we will characterize the AHR signaling dynamics in melanocytes and melanoma cells in vitro. Subsequently, we attempt to analyze the impact of AHR signaling on inflammation-induced melanoma cell plasticity and unravel the underlying molecular mechanism. In the final work package, we will analyze the impact of AHR signaling on the dynamics of melanoma cell transcriptional plasticity in response to inflammatory and therapeutic stimuli via single cell RNA sequencing. Additionally, we will also characterize AHR signaling on the differentiation trajectories of cutaneous melanocytes and melanoma cells following UVB irradiation. We expect that the insights gained from this project will provide a rationale for the future therapeutic modulation of AHR signaling in the treatment of melanoma.