Which agents are used to disrupt the G2 phase of the cell cycle?

Topoisomerase inhibitors are specifically designed to target the G2 phase of the cell cycle. During this phase, the cell prepares for mitosis, and topoisomerase enzymes are crucial for managing DNA supercoiling and entanglements that occur as DNA is replicated. By inhibiting these enzymes, topoisomerase inhibitors disrupt the replication process, leading to DNA damage and triggering apoptotic pathways in the cell, thus effectively halting the cell cycle.

Other agents, while effective in other phases of the cell cycle, do not focus on inhibiting the G2 phase specifically. Antifolates primarily target the S phase of the cell cycle by interfering with the synthesis of nucleic acids. Alkylating agents act throughout multiple phases, particularly on the DNA during replication and synthesis, without a focused action during the G2 phase. Antimetabolites also typically disrupt the S phase by mimicking and inhibiting the use of nucleotides necessary for DNA synthesis. Hence, the specificity of topoisomerase inhibitors to disrupt the G2 phase is what makes this choice the most accurate.