Mitoxyperilysis Drives Immunosuppressive Tumor Microenvironment Remodeling and Hepatocellular Carcinoma Progression via ANXA1-Mediated Macrophage M2 Polarization

Background: Mitoxyperilysis is a recently described form of regulated cell death, but its clinical and immunological relevance in hepatocellular carcinoma (HCC) remains unclear. This study investigated the prognostic significance of mitoxyperilysis-related transcriptional activity and its role in remodeling the tumor immune microenvironment. Methods: A Mitoxyperilysis Score was generated by single-sample gene set enrichment analysis. Prognostic associations were evaluated using Kaplan–Meier analysis, multivariable Cox regression, independent cohort validation, and random-effects meta-analysis. Immune infiltration and cell–cell communication were examined using bulk transcriptomic and single-cell RNA-sequencing data. The functional role of ANXA1 was assessed by ELISA, Western blotting, macrophage co-culture, immunofluorescence, flow cytometry, ANXA1 knockdown, and subcutaneous tumor models. Results: High Mitoxyperilysis Scores were associated with shorter overall survival in TCGA-LIHC (log-rank p = 0.032), although the association was attenuated after adjustment for age, sex, stage, grade, and vascular invasion. The adverse survival association was independently reproduced in the Gao2019 CHCC-HBV cohort (log-rank p = 0.00383). Across TCGA-LIHC, GSE14520, and Gao2019 CHCC-HBV, a random-effects analysis showed an overall hazard ratio of 1.42 per 1-standard-deviation increase in score (95% CI, 1.08–1.86; p = 0.011), with substantial between-cohort heterogeneity (I2 = 77.5%). High-score tumors displayed increased immune and stromal infiltration, immune-checkpoint expression, and M2-like macrophage enrichment. ANXA1 expression correlated positively with the Mitoxyperilysis Score in independent cohorts. Mitoxyperilysis induction increased both intracellular and extracellular ANXA1, while ANXA1 overexpression promoted CD163+CD206+ macrophage polarization. ANXA1 knockdown attenuated this response, reduced subcutaneous tumor burden, and decreased intratumoral CD163 staining. Conclusions: Mitoxyperilysis-related transcriptional activity is associated with adverse survival and an M2-enriched immunosuppressive microenvironment in HCC. ANXA1 is an important, although probably not exclusive, mediator of this process and may represent a potential therapeutic target.