Epigenetic reprogramming holds promise in enhancing anti-tumor efficacy of CAR T cell therapy

Chimeric antigen receptor (CAR) T cell therapy has emerged as a pivotal treatment modality for advanced hematological malignancies. However, clinical evidence suggests that CAR T cell therapy has a low response rate, poor efficacy for solid tumor, and a high complication rate. Recent research highlighted the crucial role of epigenetics in tumor immunity, particularly in modulating the fate and function of T cells. The epigenetic landscapes among T cell subpopulations show substantial differences, which in turn have a profound impact on the effector function and persistence of T cells. Epigenetic reprogramming holds promise for enhancing the persistence of CAR T cells, augmenting T cell infiltration, and ameliorating the immunosuppressive microenvironment while impeding immune evasion. In addition, biomarkers derived from the epigenetics serve as indicators to predict patient prognosis. In recent years, a growing number of clinical trials have been initiated to explore the combination of epigenetic drugs with CAR T cell therapy, highlighting the therapeutic promise of this synergistic approach in improving efficacy and overcome therapeutic resistance. However, the non-specificity of epigenetic drugs, side effects of epigenetic gene editing, poor efficacy in solid tumors, and instability of epigenetic biomarkers for predicting prognosis remain areas for further exploration. In this review, we explored the characterization of epigenetic modification landscapes across CAR T cell subpopulations, discussed how epigenetic reprogramming addresses challenges associated with CAR T cell therapy, and provided insights into the limitations of combining epigenetic strategies with CAR T cell therapy.