In recent years, the role of epigenetics in tumor initiation and progression has attracted extensive attention. In addition to genetic mutations, epigenetic alterations and post-translational modifications have been demonstrated to play crucial roles in cancer development and maintenance. Among these, protein arginine methyltransferases (PRMTs) represent an important family of epigenetic regulators that catalyze the methylation of arginine residues, thereby modulating gene expression, protein function, signal transduction, and cell cycle progression. To date, nine PRMT isoforms have been identified and are classified into three types based on their catalytic products: Type I PRMTs (e.g., PRMT1, PRMT4, PRMT6) generate asymmetric dimethylarginine (ADMA); Type II PRMTs (e.g., PRMT5, PRMT9) produce symmetric dimethylarginine (SDMA); and Type III PRMTs (e.g., PRMT7) catalyze monomethylarginine (MMA) formation. These enzymes act on both histone and non-histone substrates, establishing a complex regulatory network that integrates multiple cellular processes. Accumulating evidence indicates that PRMTs are overexpressed in various human cancers, including melanoma, multiple myeloma, glioblastoma, lung cancer, urothelial carcinoma of the bladder, gastric, cervical, ovarian, and colorectal cancers, and their dysregulation is closely associated with poor patient prognosis. Consequently, targeting PRMTs has emerged as a promising strategy for anticancer therapy. Notably, the biological effects of PRMT inhibition extend beyond chromatin regulation to RNA processing and immune signaling, providing unique therapeutic advantages and potential biomarker opportunities. Several PRMT inhibitors have demonstrated potent antitumor efficacy in preclinical and clinical studies. In the future, PRMT-targeted therapy is expected to be combined with DNMT, HDAC, or BET inhibitors, as well as DNA damage response modulators and immunotherapies, to achieve synergistic therapeutic outcomes. Collectively, PRMTs represent novel and compelling therapeutic targets with significant research and clinical potential in cancer treatment.


















