An overview of the relationship between melatonin and drug resistance in cancers.

The most common methods of treating cancer are surgery, chemotherapy, and radiotherapy. However, given that some cancers are not operable, the best method is chemotherapy and radiotherapy. Over time, people become resistant to chemotherapy drugs, and increasing the dose of the drug leads to damage to normal cells. In this article, various sources such as Google Scholar, PubMed, and Semantic Scholar were used, and articles between 1997 and 2025 that were relevant to our topic were selected. Various factors are involved in drug resistance. Melatonin is a hormone that has various roles in the body. One of its most important functions is regulating the circadian rhythm of sleep and its anti-inflammatory and antioxidant properties. According to studies, melatonin plays a role in the treatment of some diseases and cancers. The roles of melatonin in cancer treatment include anti-apoptotic, anti-angiogenic, and anti-migratory effects, as well as drug resistance and cell cycle regulation. As mentioned, one of the main reasons for the failure of cancer treatment is drug resistance, and the role of melatonin in drug resistance in cancers has been proven. Therefore, in this study, our goal is to investigate the mechanisms through which melatonin plays a role in drug resistance in different types of cancer.