Medical Pharmacology: Cancer Chemotherapy
Anti-Metabolite Practice Questions
Click on the correct answer.
Methotrexate (Trexall):
Inhibits dihydrofolate reductase (DHFR)
Reduction in tetrahydrofolate (THF) synthesis
Both
Neither
Reduction in tetrahydrofolate synthesis, secondary to methotrexate-mediated inhibition of dihydrofolate reductase (DHFR) results in which one(s) of the following?
Reduced serine synthesis
Reduced methionine synthesis
Inhibition of purine nucleotide synthesis
Inhibition of thymidylate synthesis
A & B
C & D
D only
All answers are correct (A-D)
Actions of methotrexate inhibit formation of not only DNA and RNA but also important cellular proteins.
True
False
Therapeutic effectiveness methotrexate is dependent upon cellular formation of polyglutamate metabolites which may consist of as many as 5--7 glutamate residues.
True
False
Methotrexate polyglutamates effect(s):
Inhibition of de novo purine nucleotide biosynthesis
Inhibition of thymidylate biosynthesis
Both
Neither
Folic acid, a dietary factor, is converted to tetrahydrofolate (FH4) cofactors which provide methyl groups important for thymidylate and purine synthesis.
True
False
The antifolate class of anti-metabolites:
Administration of agents from this class resulted in the first highly significant leukemia remissions (temporary)
Administration of agents from this class resulted in the first cure other solid tumor (choriocarcinoma).
Both
Neither
Methotrexate and anticancer activity:
Methotrexate administered systemically and intrathecally was central in. Combination protocols for childhood acute lymphocytic leukemia.
Methotrexate with leukovorin (rescue) extended methotrexate effectiveness in treatingosteogenic sarcoma, CNS lymphoma, systemic lymphomas and leukemias generally.
Permetrexed, a methotrexate analog, appears effective in treating lung cancer and mesothelioma..
A & B
B & C
A & C
A, B & C
Methotrexate is a direct inhibitor of folate-dependent de novo purine and thymidylate synthesis.
