A young man with leukemia is treated with methotrexate. Which of the following is the mechanism of action of this drug?
The most likely mode of action of methotrexate is by tightly binding dihydrofolate reductase (DHFR), which maintains the intracellular folate pool in its fully reduced form as tetrahydrofolates. These compounds are required in the de novo synthesis of pyrimidines and purines.
preventing absorption of folic acid
inhibiting dihydrofolate reductase
preventing formation of messenger ribonucleic acid (mRNA)
forming a cytotoxic metabolite
Oncology