Which statement best differentiates Taxanes from Vinca alkaloids?

Which statement best differentiates Taxanes from Vinca alkaloids?

• A. Taxanes destabilize microtubules
• B. Taxanes stabilize microtubules
• C. Taxanes inhibit DNA replication
• D. Taxanes inhibit RNA transcription

Answer: (B)

Taxanes and Vinca alkaloids both disrupt cell division by affecting microtubules, but they do so in opposite ways. Taxanes bind to microtubules and lock them in a stable state, preventing their normal breakdown. This stabilization stops the dynamic remodeling required during mitosis, so cells arrest in metaphase and may die. This stabilization is the key differentiator from Vinca alkaloids, which inhibit tubulin polymerization and promote microtubule disassembly, leading to defective spindle formation. Therefore, the statement taxanes stabilize microtubules is the best differentiator. The other options imply effects on DNA replication or RNA transcription, which are not the primary actions of taxanes.

Taxanes and Vinca alkaloids both disrupt cell division by affecting microtubules, but they do so in opposite ways. Taxanes bind to microtubules and lock them in a stable state, preventing their normal breakdown. This stabilization stops the dynamic remodeling required during mitosis, so cells arrest in metaphase and may die. This stabilization is the key differentiator from Vinca alkaloids, which inhibit tubulin polymerization and promote microtubule disassembly, leading to defective spindle formation. Therefore, the statement taxanes stabilize microtubules is the best differentiator. The other options imply effects on DNA replication or RNA transcription, which are not the primary actions of taxanes.