Chemotherapy Biotherapy Certification ONS Practice Testq

What is a key feature of antimetabolite drugs in cancer treatment?

1. They are specific for solid tumors

2. They create false messages during DNA replication

3. They disrupt the M phase of the cell cycle

4. They can cross the blood-brain barrier

The correct answer is: They create false messages during DNA replication

A key feature of antimetabolite drugs in cancer treatment is that they create false messages during DNA replication. Antimetabolites are designed to mimic the normal substrates that are used in the production of nucleic acids. When these drugs enter the metabolic pathways, they interfere with the synthesis of DNA and RNA by substituting for the actual metabolites. This can lead to the incorporation of faulty nucleotides into the DNA strand during replication, which disrupts the normal function of the DNA and can induce apoptosis in rapidly dividing cancer cells. This mechanism is particularly effective in treating cancers that are characterized by high rates of cell division, as systemic interference with nucleic acid synthesis can significantly hinder the growth of these tumors. The other options, while relevant to certain chemotherapy agents, do not specifically characterize the action of antimetabolites. For example, antimetabolites are not exclusively specific for solid tumors and do not universally act by disrupting the M phase of the cell cycle; rather, they mainly affect the S phase, where DNA synthesis occurs. Additionally, not all antimetabolites can cross the blood-brain barrier, which limits their effectiveness in treating central nervous system tumors.