Which of the following antineoplastic drugs targets rapidly replicating cells withoutaffecting DNA…

➤ How does vincristine differ mechanistically from methotrexate, doxorubicin, and cyclophosphamide?
Vincristine blocks microtubule assembly and acts during M phase. Methotrexate inhibits dihydrofolate reductase and blocks nucleotide synthesis in S phase. Doxorubicin intercalates DNA and inhibits topoisomerase II, causing double-strand breaks. Cyclophosphamide alkylates DNA to form crosslinks. These differences determine cell-cycle specificity, cytotoxic profiles, and clinical toxicities.