Tabriz University of Medical Sciences BioImpacts 2228-5652 16 1 2026 01 04 Comprehensive pan-cancer analysis and experimental validation of mitotic arrest defective 2-like 1 (MAD2L1) in colorectal cancer 32796 32796 10.34172/bi.32796 EN Qingqing Wu https://orcid.org/0000-0003-4160-150X Zhuangzhuang Tian Liyu Cao https://orcid.org/0000-0003-2130-6554 Journal Article 10.34172/bi.32796 2025 09 13 2025 11 29 Introduction: This study investigates the function of MAD2L1 through comprehensive bioinformatics analysis of pan-cancer data and molecular functional validation experiments, with a particular focus on colorectal cancer. Methods: We analyzed MAD2L1 expression, prognosis, genetic and epigenetic alterations, immune infiltration, and copper apoptosis-related genes across multiple cancers. A lncRNA–miRNA–MAD2L1 regulatory network was constructed for CRC. Drug sensitivity related to MAD2L1 was assessed via GSCALite. Functional assays included GO/KEGG enrichment, RT-PCR, Western blot, CCK-8, cell cycle, and apoptosis analysis. Results: A comprehensive pan-cancer analysis revealed that MAD2L1 has diagnostic and prognostic value. Its expression correlated with methylation, immune cell infiltration, and immune checkpoint genes. In CRC, a lncRNA–miRNA–MAD2L1 network appears to regulate tumor progression. Enrichment analysis linked MAD2L1 to DNA replication and chromosome segregation. Functional experiments showed that MAD2L1 promotes proliferation and inhibits apoptosis, likely via cell cycle regulation. Conclusion: MAD2L1 is a potential biomarker for diagnosis, prognosis, immune response, and drug sensitivity in pan-cancer, including CRC. It facilitates tumor progression through a lncRNA-miRNA–miRNA network and regulates proliferation and apoptosis via DNA replication and cell cycle pathways.