A cough syrup can make resistant breast cancer cells receptive to therapy. Researchers at the University of Basel discovered this by accident. The promising results for breast cancer patients were published on Tuesday in the journal Cell Reports Medicine. In the case of advanced breast cancer, treatment often fails because the tumors develop resistance to the drug. This is the case, for example, with the active substance alpelisib.
This active ingredient was approved in Switzerland three years ago for the treatment of breast cancer. “Unfortunately, however, it turned out that the success of the drug is severely limited by resistance,” said study leader Mohamed Bentires-Alj in a statement from the University of Basel on Tuesday.
The researchers therefore investigated which genetic changes lead to resistance. The result: mutations turned off a protein called NF1. This lack of NF1 disrupts certain mechanisms in the cell, which prevents the success of the therapy.
An analysis by the researchers showed that the loss of NF1 has an impact on the cell’s energy balance. Because of these changes, the researchers conducted experiments with the well-known antioxidant N-acetylcysteine, which has a similar effect on energy metabolism and was therefore intended to mimic the effects of NF1 loss. N-acetylcysteine is a well-known dietary supplement, as well as an ingredient in expectorant drugs and cough syrups.
To the researchers’ surprise, however, the substance had the opposite effect: it restored and even enhanced the effect of alpelisib in resistant cancer cells. This is done through an additional intervention in another signaling pathway, which also plays an important role in tumor growth, as the researchers discovered through further analysis.
Bentires-Alj thinks that combining N-acetylcysteine with alpelisib could improve the treatment of advanced breast cancer. The next step would now be to confirm the positive effects observed in the laboratory in clinical studies with breast cancer patients.