This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Cancer, Subject name: Pharmacology
[{'content': 'Pemetrexed MOA is: \nSelect and explain. \nA. RNA synthesis inhibitor, B. Dihvdrofolate reductase inhibitor, C. Dopamine agonist, D. Folate antagonist', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ref: Goodman & Gillman's 13th ed. P 1179* Pemetrexed is a most recent folate analogue which is avidly transported into cells via the reduced folate carrier and is converted to its metabolite (PGs- Polyglutamate) that inhibit Thymidylate synthase and glycine amide ribonucleotide transformylase, as well as DHFR. (Dihydrofolate Reductase)* It is even more potent than methotrexate.* Like MTX, it induces p53 and cell-cycle arrest, but this effect does not depend on induction of p21.* Use: It has activity against ovarian cancer, mesothelioma, and adenocarcinomas of the lung.* Other effects and side effects are similar to methotrexate like myelosuppression, GI toxicity. The toxicity can be attenuated with folate and vitamin B12 supplementation.* A newer congener, pralatrexate, is more effectively taken up and polyglutamated than MTX and is approved for treatment of CTCL peripheral T cell lymphoma.* Pramipexole is an antiparkinsonism drug which is a dopamine agonist.", 'role': 'assistant'}]