Which types of cells are most significantly impacted by antimetabolites?

Antimetabolites are a class of chemotherapy agents that interfere with DNA and RNA synthesis, primarily targeting cellular processes that occur during DNA replication. They resemble natural metabolites and can disrupt the normal functioning of enzymes involved in DNA synthesis, leading to cell cycle arrest and ultimately cell death.

Cells with high division rates are significantly impacted by antimetabolites because these drugs specifically target the S phase of the cell cycle, where DNA synthesis occurs. Rapidly dividing cells—such as those found in tumors as well as in healthy tissues like the bone marrow, gastrointestinal tract, and hair follicles—are more susceptible to the effects of antimetabolites. This is due to their reliance on the synthesis of DNA and RNA to facilitate their rapid proliferation.

In contrast, slowly dividing cells and resting cells are less affected because they are not actively replicating their DNA and are often in phases of the cell cycle that are less vulnerable to the disruptive effects of antimetabolites. Therefore, antimetabolites are particularly effective against tumors that have a high growth fraction, enhancing their role in cancer treatment. All cell types are not impacted equally; the action of antimetabolites is distinctly more pronounced in cells with high division rates.