Scientists find way to starve cancer cells without harming healthy cells

(Web Desk) - Many cancer treatments harm healthy tissue along with tumors, often leading to serious side effects. To reduce this collateral damage, researchers are searching for therapies that act only on cancer cells.

An international research team led by the Universities of Geneva (UNIGE) and Marburg has identified an unusual approach involving a “mirror” version of the amino acid cysteine.

This sulfur-containing molecule sharply slows the growth of certain cancers while leaving healthy cells unaffected. Because it is taken up mainly by specific cancer cells, the compound disrupts essential functions such as cellular respiration and DNA production.

In experiments with mice, this strategy significantly reduced the growth of aggressive breast tumors, suggesting a promising and highly targeted treatment avenue. The results are reported in Nature Metabolism.

The research team, led by Jean-Claude Martinou, Honorary Professor in the Department of Molecular and Cellular Biology at the UNIGE Faculty of Science, examined how different amino acids influence cancer cell behavior. Their experiments revealed that the D form of cysteine (D-Cys), which contains a sulfur atom, strongly suppresses the growth of certain cancer cells in laboratory conditions.

Notably, healthy cells were unaffected, highlighting a striking level of selectivity.

“This difference between cancer cells and healthy cells is easily explained: D-Cys is imported into cells via a specific transporter that is present only on the surface of certain cancer cells,” explains Joséphine Zangari, a PhD student in Professor Martinou’s laboratory and the study’s first author.

“In fact, we observed that if we express this transporter on the surface of healthy cells, those cells stop proliferating in the presence of D-Cys.”

Thanks to a collaboration with the team of Professor Roland Lill at the University of Marburg, the scientists uncovered how D-Cys exerts its toxicity: “It blocks an essential enzyme called NFS1, located in the mitochondria – the cell’s ‘powerhouses’.

This enzyme plays a key role in producing iron-sulfur clusters, small structures that are indispensable for many processes such as cellular respiration, DNA and RNA production, and maintaining genetic integrity,” explains Roland Lill.