黑色素瘤细胞的表型异质性对于患有进展性疾病的患者而言，会导致耐药性增加、转移能力增强以及免疫规避。以往的研究已经单独报道了多种机制对于肿瘤内部和肿瘤间的表型异质性产生影响，比如IFNγ信号传导和增殖转化为侵袭性过程，然而它们如何相互作用对于肿瘤进展的影响还是不够清楚。在本研究中，我们结合动力系统建模与批量和单细胞水平的转录组数据分析，探究了黑色素瘤表型异质性的潜在机制以及其对于靶向治疗和免疫检查点抑制剂适应性的影响。我们构建了一个涉及与该过程有关的转录因子的最小核心调控网络，并确定了这个网络所能实现的表型景观中的多个“吸引子”。我们的模型预测关于PD-L1在IFNγ信号传导和增殖转化之间的协同调控已经在三个黑色素瘤细胞系——MALME3，SK-MEL-5和A375中得到了实验验证。我们展示了我们的调控网络（包括MITF，SOX10，SOX9，JUN和ZEB1）的紧密动力学可以复现关于多种表型（增殖型，神经嵴样，浸润性）的共存及其之间可逆的细胞状态转换的实验观察结果，包括对靶向治疗和免疫检查点抑制剂的响应。这些表型表现出不同水平的PD-L1，驱动了免疫抑制的异质性。这种PD-L1的异质性可以通过这些调节因子与IFNγ信号传导的联合动力学而加剧。我们的模型关于增殖转化和PD-L1水平在黑色素瘤细胞规避靶向治疗和免疫检查点抑制剂时的变化已经在离体和体内实验的多个RNA-seq数据集中得到了验证。我们经过校准的动力学模型为测试联合治疗提供了平台，并为转移性黑色素瘤的治疗提供了合理途径。我们对于PD-L1表达、增殖转化为侵袭性过程和IFNγ信号传导之间的相互作用的改进理解可以用于改善对于难治性和转移性黑色素瘤的临床管理。© 作者（或其雇主）2023。经许可进行再使用，按照CC BY-NC进行。不得进行商业性再利用。由BMJ出版。

Phenotypic heterogeneity of melanoma cells contributes to drug tolerance, increased metastasis, and immune evasion in patients with progressive disease. Diverse mechanisms have been individually reported to shape extensive intra-tumor and inter-tumor phenotypic heterogeneity, such as IFNγ signaling and proliferative to invasive transition, but how their crosstalk impacts tumor progression remains largely elusive.Here, we integrate dynamical systems modeling with transcriptomic data analysis at bulk and single-cell levels to investigate underlying mechanisms behind phenotypic heterogeneity in melanoma and its impact on adaptation to targeted therapy and immune checkpoint inhibitors. We construct a minimal core regulatory network involving transcription factors implicated in this process and identify the multiple 'attractors' in the phenotypic landscape enabled by this network. Our model predictions about synergistic control of PD-L1 by IFNγ signaling and proliferative to invasive transition were validated experimentally in three melanoma cell lines-MALME3, SK-MEL-5 and A375.We demonstrate that the emergent dynamics of our regulatory network comprising MITF, SOX10, SOX9, JUN and ZEB1 can recapitulate experimental observations about the co-existence of diverse phenotypes (proliferative, neural crest-like, invasive) and reversible cell-state transitions among them, including in response to targeted therapy and immune checkpoint inhibitors. These phenotypes have varied levels of PD-L1, driving heterogeneity in immunosuppression. This heterogeneity in PD-L1 can be aggravated by combinatorial dynamics of these regulators with IFNγ signaling. Our model predictions about changes in proliferative to invasive transition and PD-L1 levels as melanoma cells evade targeted therapy and immune checkpoint inhibitors were validated in multiple RNA-seq data sets from in vitro and in vivo experiments.Our calibrated dynamical model offers a platform to test combinatorial therapies and provide rational avenues for the treatment of metastatic melanoma. This improved understanding of crosstalk among PD-L1 expression, proliferative to invasive transition and IFNγ signaling can be leveraged to improve the clinical management of therapy-resistant and metastatic melanoma.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.