Which class of chemotherapy agents primarily targets DNA replication?

Antimetabolites are a class of chemotherapy agents that primarily target DNA replication. These drugs work by mimicking the building blocks of DNA and RNA, which disrupts the synthesis of nucleic acids necessary for cell replication and division. By interfering with the incorporation of these essential components into DNA, antimetabolites effectively impede the replication process during the S phase of the cell cycle. This action leads to cell death, particularly in fast-growing cancer cells that are highly reliant on rapid DNA synthesis for their proliferation.

The use of antimetabolites is particularly common in treating various types of cancer, including leukemia, breast cancer, and gastrointestinal cancers. Their mechanism of action highlights the importance of nucleotide synthesis in tumor growth, making them effective in targeting not just cancer cells, but also affecting normal cells that rapidly divide.

In contrast, alkylating agents work by directly damaging DNA through the formation of cross-links, which prevents replication. Taxanes and microtubule inhibitors primarily interfere with the mitotic spindle and cell division rather than targeting the DNA replication process itself. Thus, while all of these classes play important roles in cancer treatment, antimetabolites uniquely focus on disrupting the essential processes involved in DNA replication.