Radiosensitizer

A radiosensitizer is not a single molecule or receptor but rather a broad class of agents—drugs or chemicals—that make tumor cells more sensitive to the effects of radiation therapy. These agents are used alongside radiotherapy primarily in cancer treatment with the goal of enhancing the killing effect on tumor cells while minimizing harm to normal tissues. Radiosensitizers work through various mechanisms such as increasing DNA damage induced by radiation, inhibiting cellular repair processes that would otherwise fix this damage, altering cell cycle progression so that more cells are vulnerable during irradiation, and modifying hypoxic conditions within tumors that typically confer radioresistance. Common radiosensitizing drugs include certain chemotherapeutics like gemcitabine and cisplatin as well as specialized compounds like nitroimidazoles. The use of radiosensitizers is particularly important for treating tumors that are resistant to standard doses of radiotherapy due to factors like hypoxia or efficient DNA repair mechanisms within cancer cells. While effective at improving therapeutic outcomes in some cancers, their use can be associated with increased acute and chronic toxicities depending on the agent used and patient-specific factors. Note: "Radiosensitizer" does not refer to a specific molecular target such as an enzyme or receptor but rather describes any agent with this functional property; therefore it is not considered a canonical therapeutic target itself but rather an intervention strategy involving multiple possible targets/mechanisms.

Other names

RadiosensitizerRadiation sensitizerRadio-enhancer

Radiosensitizers enhance DNA damage caused by radiation or inhibit its repair through several mechanisms: - Incorporation into DNA to increase susceptibility to radiation-induced damage. - Inhibition of DNA repair enzymes or pathways. - Induction of cell cycle arrest in radiosensitive phases such as G2/M. - Mimicking oxygen to enhance free radical formation in hypoxic tumor cells.