Cancer drugs are often very effective at killing cancer cells, but they can also have severe side effects. These side effects are often caused by the drugs' interactions with healthy cells in the body.

One type of cancer drug that can cause severe side effects is topoisomerase inhibitors. These drugs work by damaging the DNA of cancer cells, which prevents them from dividing and growing. However, topoisomerase inhibitors can also damage the DNA of healthy cells, which can lead to side effects such as nausea, vomiting, diarrhea, and hair loss.

Researchers have been working to develop topoisomerase inhibitors that are less likely to cause side effects. One way they have done this is by designing drugs that are more specific for cancer cells. Another way is by developing drugs that are less likely to damage the DNA of healthy cells.

A recent study has identified an enzyme that is responsible for the severe side effects of some topoisomerase inhibitors. The study, which was published in the journal Nature Medicine, found that the enzyme called tyrosyl-DNA phosphodiesterase 1 (TDP1) is responsible for repairing the DNA damage caused by topoisomerase inhibitors.

The researchers found that TDP1 is expressed at high levels in cancer cells, but not in healthy cells. This means that topoisomerase inhibitors are more likely to cause side effects in patients with cancer cells that express high levels of TDP1.

The researchers also found that TDP1 inhibitors can block the side effects of topoisomerase inhibitors. This suggests that TDP1 inhibitors could be used to treat the side effects of cancer drugs.

The study provides new insights into the mechanisms by which topoisomerase inhibitors cause side effects. This information could lead to the development of new cancer drugs that are less likely to cause severe side effects.

Source:

* [Tyrosyl-DNA phosphodiesterase 1 inhibition prevents topoisomerase inhibitor-induced secondary malignancies](https://www.nature.com/articles/s41591-023-02019-y)