Role of Melatonin in Cancer: Effect on Clock Genes Rodríguez Santana, César Florido Ruiz, Javier Martínez Ruiz, Laura López Rodríguez, Alba Acuña Castroviejo, Darío Escames Rosa, Germaine Melatonin Cancer Clock genes Circadian rhythms SIRT1 c-Myc The circadian clock is a regulatory system, with a periodicity of approximately 24 h, that generates rhythmic changes in many physiological processes. Increasing evidence links chronodisruption with aberrant functionality in clock gene expression, resulting in multiple diseases, including cancer. In this context, tumor cells have an altered circadian machinery compared to normal cells, which deregulates the cell cycle, repair mechanisms, energy metabolism and other processes. Melatonin is the main hormone produced by the pineal gland, whose production and secretion oscillates in accordance with the light:dark cycle. In addition, melatonin regulates the expression of clock genes, including those in cancer cells, which could play a key role in the numerous oncostatic effects of this hormone. This review aims to describe and clarify the role of clock genes in cancer, as well as the possible mechanisms of the action of melatonin through which it regulates the expression of the tumor’s circadian machinery, in order to propose future anti-neoplastic clinical treatments. 2023-03-21T12:35:29Z 2023-03-21T12:35:29Z 2023-01-18 journal article Rodríguez-Santana, C... [et al.]. Role of Melatonin in Cancer: Effect on Clock Genes. Int. J. Mol. Sci. 2023, 24, 1919. [https://doi.org/10.3390/ijms24031919] https://hdl.handle.net/10481/80720 10.3390/ijms24031919 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI