To summarize how circadian regulation shapes tumor rhythmicity and its implications for immune modulation and chronotherapy in the tumor microenvironment (TME).
Approach:
Circadian Clock Architecture: Describes the organization of the mammalian circadian system, including the role of the suprachiasmatic nucleus and its integration of environmental signals with physiological programs.
Molecular Mechanisms: Explains the transcriptional–translational feedback loops involving CLOCK, BMAL1, PER, CRY, REV-ERB, and ROR that generate circadian rhythms at the cellular level.
Immune Modulation: Discusses the time-dependent features of immune responses within the TME, including dendritic cell migration, antigen presentation, CD8+ T cell infiltration, and T cell exhaustion.
Therapeutic Strategies: Explores emerging therapies that leverage circadian biology, including small-molecule clock modulators, rhythm-responsive nanomedicine, chronologically optimized CAR-T cell therapy, and time-of-day-dependent immune checkpoint blockade.
Key Findings:
Circadian rhythms influence tumor initiation, progression, and therapeutic response.
The TME exhibits temporal organization that affects immune competence.
Treatment timing may enhance anti-tumor efficacy and reduce toxicity.
Interpretation:
Limitations:
Most mechanistic evidence remains preclinical.
Many clinical observations are retrospective.
Conclusion:
Future opportunities include microbiome-informed chronotherapy and multi-omics profiling to enhance treatment strategies.
