Circular RNAs in Cancer: Epigenetic Regulation, Dual Functions and Clinical Translation

Circular RNAs (circRNAs), a class of non-coding RNAs with a closed-loop structure, have emerged as a focal point in cancer research due to their stability, tissue specificity, and high abundance in body fluids. This paper systematically elaborates on the dual roles of circRNAs in cancer. Specifically, they can act as tumor suppressors to inhibit tumor progression or as oncogenes to promote tumorigenesis. Their core mechanisms involve epigenetic regulation, including modulation of DNA methylation, histone post-translational modifications, and functioning as miRNA sponges to affect target gene expression. CircRNAs regulate cancer hallmarks through these mechanisms, such as cell proliferation, apoptosis resistance, angiogenesis, and invasion-metastasis. Additionally, due to their unique biological properties, circRNAs show great potential in cancer diagnosis and prognostic evaluation. Intervention strategies targeting the circRNA-epigenetic axis, such as antisense oligonucleotides and CRISPR technology, provide new directions for cancer therapy. This study aims to deeply analyze the complex regulatory networks of circRNAs in tumorigenesis and progression, explore key challenges in their translation from basic research to clinical practice, and offer theoretical basis and practical references for understanding epigenetic dysregulation in cancer and developing novel diagnostic and therapeutic approaches.