I need to know two ways that chemotherapy drugs might inhibit DNA replication and sides effects?

Answered here: https://biology-forums.com/index.php?topic=332636.0

Also keep in mind that the chemotherapeutic agents inhibit DNA in any dividing cell and not specifically in only cancerous cells. therefore, the side effects include the non-division of normally dividing cells like skin, hair cells, liver etc that are nearby. thus u see such patients undergoing chemotherapy with hair loss and pale skin sometimes with scabs, sometimes also with some organ failures. Furthermore, scientists are still working with studying the surface molecules especially receptors on cancer cells (which have many more receptors than normal cells). they will then identify some antigens specific only to cancer cells and can thus synthesize antibodies specific only to cancer cells and then fuse them with the chemotherapeutic agents so that these agents can specifically localize only at cancerous cells and greatly reduce the side effects, such as the action on non-cancerous cells

Thank you! the second part of the question was answered well, but the first part of my question was not answered in the link you included, so I was wondering if you could answer the first part as well. Thanks again.

You're right, my bad. So the way we teach how chemotherapy works is generally by saying it stops cells from replicating OR slows it down. First know that there are many different types of chemotherapy drugs, including alkylating agents, antimetabolites, anti-tumor antibiotics, topoisomerase inhibitors, mitotic inhibitors, and corticosteroids.

Alkylating agents modify DNA bases, which interferes with DNA replication and transcription. Although alkylating agents affect transcription, this isn’t the aim of the treatment. The goal of using alkylating agents in chemotherapy is to produce enough DNA damage to cause the cell to undergo apoptosis (programmed cell death). Furthermore, some chemotherapy drugs that affect transcription also inhibit ribosomal RNA transcription. And ribosomes play an integral role in the process of translation. Obviously with this, one of the downsides of chemotherapy is that not only are cancer cells destroyed, but healthy cells are also killed in the process.

So, there are a lot of mechanisms at play with chemotherapy drugs. As a second mechanism, you could describe how it disrupts mitosis. Mitotic inhibitors work by interfering with and halting mitosis (usually during the M phase of the cell cycle), so that the cell will no longer divide. Tubulin, a necessary protein for mitosis to occur, is suppressed by the mitotic inhibitor, preventing mitosis altogether.