Which class of agents cross-links DNA strands, causing abnormal base pairing?

The class of agents that cross-links DNA strands, leading to abnormal base pairing, is alkylating agents. These drugs work by adding alkyl groups to the DNA, which creates cross-links between DNA strands. As a result, this can inhibit DNA replication and transcription, ultimately triggering cell death, especially in rapidly dividing cancer cells.

Alkylating agents are particularly effective because they interfere with the DNA’s ability to accurately replicate and divide, causing cellular dysfunction and apoptosis. This mechanism is critical in cancer treatment as it directly targets the rapidly dividing tumor cells while also potentially affecting normal cells.

In contrast, antimetabolites primarily disrupt DNA and RNA synthesis by mimicking the building blocks of nucleic acids, while topoisomerase inhibitors interfere with the enzymes that help uncoil DNA for replication and transcription. Taxanes are a class of chemotherapy that prevent cell division by stabilizing microtubules, ultimately affecting the mitotic spindle during cell division. Each of these classes works through distinct mechanisms, but it is the alkylating agents that specifically cause DNA cross-links to induce the kind of cellular damage described.