Mitoxyperilysis-based molecular subtyping identifies SPP1+ macrophages and IL1B as critical mediators of tumor progression and immunotherapy resistance in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy characterized by poor clinical outcomes. Although mitoxyperilysis has recently emerged as a novel form of regulated cell death, the clinical relevance of mitoxyperilysis-related molecular subtypes in ICC remains largely unexplored. This study aimed to elucidate the clinical significance, immune microenvironment features, and potential therapeutic targets of mitoxyperilysis-related molecular subtypes in ICC. Based on the expression profiles of 45 mitoxyperilysis-related genes, ICC patients were classified into two subtypes using consensus clustering, and the robustness of the classification was validated in the independent GSE89749 cohort. Survival analysis, immune microenvironment characterization, single-cell transcriptomic profiling, in vitro/in vivo experiments, and nomogram construction were subsequently performed to investigate the underlying biological mechanisms and therapeutic implications. Two robust mitoxyperilysis-related molecular subtypes were identified. Patients in the high-mitoxyperilysis subtype exhibited significantly poorer overall survival (OS), and subtype classification remained an independent predictor of adverse prognosis. The high-mitoxyperilysis subtype was closely associated with lymph node metastasis, elevated CA19-9 levels, and KRAS mutation. Furthermore, this subtype demonstrated pronounced inflammatory activation, an immunosuppressive tumor microenvironment (TME), increased infiltration of neutrophils and M2 macrophages, and elevated expression of immune checkpoint molecules. Single-cell transcriptomic analysis revealed a marked enrichment of SPP1 + macrophages in the high-mitoxyperilysis subtype, with IL1B and CXCL3 identified as key regulatory molecules. IL1B promoted ICC cell invasion and metastasis. Notably, treatment with diacerein, an IL1B inhibitor, synergized with anti-PD-1 immunotherapy to suppress tumor progression and overcome immunotherapy resistance. Mitoxyperilysis-related molecular classification provides a clinically relevant framework for prognostic stratification and prediction of immunotherapeutic responsiveness in ICC. SPP1 + macrophages and IL1B represent potential therapeutic targets, providing a promising strategy for precise diagnosis and treatment of ICC.