Controlling Temozolomide Efficacy by Light-Dependent Inhibition of O6‑Methylguanine DNA Methyltransferase.

The DNA repair enzyme O6-Methylguanine DNA Methyltransferase (MGMT) is a major contributor in conferring resistance to alkylating agents such as temozolomide (TMZ) in cancers. The use of MGMT inhibitors can suppress resistance and enhance the efficacy of TMZ. However, current inhibitors are nonselective for cancer cells, and as a result, MGMT is also inhibited in healthy cells leading to severe side effects. Here, we report the development of a photoactivatable MGMT inhibitor, whereby irradiation is required for MGMT inhibition and subsequent enhancement of the TMZ sensitivity in T98G cells. This strategy is promising for tissue-specific therapy, whereby TMZ efficacy can only be enhanced in the cancerous region and not healthy tissue, controlled spatially by light.