The mechanism of anti cancer action of fluoruracil is: (A) Cross linking of double standard DNA and the resulting inhibition of DNA replication and transcription, (B) Cytotoxicity resulting from metabolite that interferes with the production of dTMP, (C) Irreversible inhibition of dihydrofolic acid reductase, (D) Selective action of DNA polymerase
Answer is C. 5-FU is an antimetabolite.it us a thymidine analogue and acts by conversion to 5'-dUMP .latter inhibits the formation of dTMP and result in Thymineless dealth of cells Ref-KDT 6/824