Which two pyrimidine analogs are known to target thymidylate synthase?

The two pyrimidine analogs that specifically target thymidylate synthase are 5-Fluorouracil and Capecitabine. These drugs are known for their role in cancer therapy, particularly in the treatment of solid tumors such as colorectal cancer.

5-Fluorouracil (5-FU) is a well-established antimetabolite that mimics uracil and inhibits thymidylate synthase, an enzyme crucial for the synthesis of thymidine, which is necessary for DNA replication. By inhibiting this enzyme, 5-FU effectively reduces the availability of thymidine, leading to disrupted DNA synthesis and ultimately inducing apoptosis in rapidly dividing cancer cells.

Capecitabine is an oral prodrug of 5-FU that is converted into active 5-FU in the body. It allows for more convenient administration while retaining the same mechanism of action against thymidylate synthase. By effectively delivering 5-FU, Capecitabine maintains the therapeutic benefits in targeting thymidylate synthase.

The other choices consist of different classes of chemotherapy agents that do not primarily target thymidylate synthase. Options like Dihydrofolate and Tetrahydrofolate are related