Antitumor antibiotics exert their effects by which mechanism?

Antitumor antibiotics exert their effects by which mechanism?

• A. Stabilize microtubules
• B. Bind directly to DNA, inhibiting DNA synthesis and transcription
• C. Cross-link DNA to prevent replication
• D. Inhibit topoisomerase

Answer: (B)

Antitumor antibiotics mainly work by interacting with DNA and disrupting its function, which blocks DNA replication and RNA transcription. When these drugs bind to DNA, they often intercalate between base pairs or otherwise distort the DNA helix, making it harder for DNA and RNA polymerases to copy and read the genetic code. Because cancer cells are rapidly dividing, they are especially susceptible to this disruption, leading to cell death. That makes the idea of binding directly to DNA and inhibiting DNA synthesis and transcription the best description of their general mechanism. Stabilizing microtubules describes a different class of drugs that target mitosis, not the classic action of these antibiotics. Cross-linking DNA is true for some agents within the broader category but isn’t the universal mechanism across all antitumor antibiotics. Inhibiting topoisomerase is characteristic of topoisomerase inhibitors, a separate mechanism outside the primary action of most antitumor antibiotics.

Antitumor antibiotics mainly work by interacting with DNA and disrupting its function, which blocks DNA replication and RNA transcription. When these drugs bind to DNA, they often intercalate between base pairs or otherwise distort the DNA helix, making it harder for DNA and RNA polymerases to copy and read the genetic code. Because cancer cells are rapidly dividing, they are especially susceptible to this disruption, leading to cell death.

That makes the idea of binding directly to DNA and inhibiting DNA synthesis and transcription the best description of their general mechanism. Stabilizing microtubules describes a different class of drugs that target mitosis, not the classic action of these antibiotics. Cross-linking DNA is true for some agents within the broader category but isn’t the universal mechanism across all antitumor antibiotics. Inhibiting topoisomerase is characteristic of topoisomerase inhibitors, a separate mechanism outside the primary action of most antitumor antibiotics.