KROK 1 2008 – Question 190 · KROK (Medicine) · Biological Chemistry
An oncological patient was prescribed methotrexate. With the lapse of time target cells of the tumour lost susceptibility to this drug. There is change of gene expression of the following enzyme:
- A. Thiaminase
- B. Deaminase
- C. Folate oxidase
- D. Folate decarboxylase
- E. Dihydrofolate reductase
Hint
Methotrexate is a folate analogue that blocks the enzyme regenerating tetrahydrofolate; resistant tumour cells typically change how much of that target enzyme they produce.
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