Chemotherapy Biotherapy Certification ONS Practice Test 2025 - Free Practice Questions and Study Guide

The common mechanism of action for antitumor antibiotics primarily involves the inhibition of DNA and RNA synthesis. Antitumor antibiotics, such as doxorubicin and bleomycin, interact with the DNA molecule in various ways. They can intercalate between DNA base pairs, thereby disrupting the helix structure. This interference leads to the prevention of DNA replication and transcription, which are critical processes for cell division and tumor growth.

In addition to interfering with DNA synthesis, some antitumor antibiotics may exert their effects by generating reactive oxygen species or by causing double-strand breaks in the DNA, ultimately leading to cell cycle arrest and apoptosis. The key point here is that their action is predominantly focused on the DNA and RNA synthesis pathways rather than alteration of the cell membrane environment, blocking S phase enzymes, or directly inducing apoptosis as a primary mechanism.

Overall, understanding the mechanism of action is crucial when considering the therapeutic applications and potential side effects of these drugs in the context of cancer treatment.