Abstract 7232: KDM1A/UTX Mutations Modulate Innate Immune Responses to Influence Immunotherapy Outcomes in Lung Squamous Cell Carcinoma

Abstract Introduction: Immunotherapy has come of age for lung cancers, especially lung squamous cell carcinoma (LUSC), which lacks targeted therapies . KDM6A/UTX is frequently mutated in LUSC and is associated with poor prognosis. However, the mechanisms by which KDM6A/UTX mutations influence the efficacy of immunotherapy in LUSC remain unclear. Methods: We developed genetically engineered murine models of LUSC by culturing lung organoids from adult C57B/L6 mice, using Cas9 and sgRNAs to introduce driver mutations of LUSC. These organoids were then orthotopically transplanted into the lungs of recipient C57B/L6 mice to establish in vivo LUSC models. Tumor growth and progression were monitored through live imaging and micro-CT. Histopathological assays were performed to validate the models' accuracy in representing human LUSC. Multi-omics methods were used to analyze the the biological behavior of Kdm6a-mutant tumor cells, their response to immunotherapy, and identify key regulatory target genes. Potential therapeutic targets identified through these analyses are currently under further validation. Results: A LUSC mouse models with sgTrp53; sgPten; SOX2; Myc; Cas9 (TPSM) was established. Histopathological analyses showed that these models represented the features of human disease. Tumor organoids were successfully developed from these models and serial transplantation confirmed that these organoids remained the characteristics of the original models. Loss of Kdm6a/UTX significantly enhanced the growth of LUSC tumor organoids in vivo and promoted metastasis. Notably, LUSC tumors with Kdm6a/UTX mutations exhibited a poor response to immune checkpoint inhibitors (ICIs), and showed significantly shortened survival in treated mice. Multi-omics analyses revealed that Kdm6a/UTX mutations upregulated several pathways associated with tumor progression, including focal adhesion, epithelial-mesenchymal transition (EMT), and epithelial cell migration. In contrast, immune-related pathways such as virus response and interferon-β signaling were downregulated. These mutations also resulted in a decreased recruitment of immune cells, including cytotoxic T cells (CD8+), into the tumor microenvironment, potentially contributing to immune evasion and the poor response to immunotherapy. Conclusion: The new LUSC mouse models developed in this study provide a platform for investigating the mechanisms of LUSC progression and response to immunotherapy. Our results suggest that Kdm6a/UTX play a critical role in modulating the tumor immune microenvironment, promoting immune evasion, and reducing the efficacy of immunotherapy. Further validation of the identified molecular targets and their therapeutic potential is underway. Citation Format: Feifei Na, Xiaofeng Deng, Yuying Wang, Zhenkun Zhang, Yang Yang, Liting You, Zuoyu Liang, Yu Liu, Chong Chen. KDM1A/UTX Mutations Modulate Innate Immune Responses to Influence Immunotherapy Outcomes in Lung Squamous Cell Carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7232.