HCN2 Promotes BGN Transcription via REST to Regulate Ferroptosis and Tumor Progression in Bladder Cancer

Bladder cancer is one of the most common malignancies of the urinary system. Identifying new potential therapeutic targets and exploring molecular mechanisms are crucial for improving treatment and prognosis. The hyperpolarization-activated cyclic nucleotide-gated (HCN) channel 2, known to play a key role in various physiological and pathological processes, has an unclear function and mechanism of action in bladder cancer. We employed bioinformatics analysis and immunohistochemistry to assess the role of HCN2 in bladder cancer, integrating in vitro and in vivo models to evaluate the impact of HCN2 on cell behavior. Molecular interactions were characterized using immunoprecipitation, chromatin immunoprecipitation, and dual-luciferase reporter assays. Our investigation revealed a significant upregulation of HCN2 in bladder cancer tissues, which was predictive of a poorer clinical outcome. Functionally, HCN2 knockdown in bladder cancer impeded cell proliferation, induced apoptosis, and curtailed migration and invasion. Mechanistically, the overexpression of HCN2 contributed to the translocation of the REST transcription factor into the nucleus and facilitated its binding to the BGN promoter for transcriptional activation of its expression. This regulatory mechanism was shown to suppress ferroptosis, a form of regulated cell death, thereby enhancing the proliferative and tumorigenesis of bladder cancer cells. This study uncovers the novel mechanism by which HCN2 regulates ferroptosis via the REST-BGN axis, affecting bladder cancer cell behavior, and provides new perspectives and strategies for future clinical treatment.