Reacción a "A study in mice and human tissue shows that the antioxidant glutathione feeds cancer cells"

Strategies targeting tumour metabolism represent approaches that could improve the effectiveness of various therapies. We know that caloric restriction and other forms of fasting induce changes in the metabolism of these cells, forcing them to reduce their reliance on glucose and increase the use of mitochondrial oxidative pathways. However, this work once again highlights the remarkable metabolic plasticity of tumour cells—a key aspect of cancer biology—which allows them to adapt to adverse nutritional conditions and, in many cases, to develop therapy resistance.

On this occasion, the authors expand our understanding of glutathione biology and identify extracellular glutathione (GSH), abundant in the tumour microenvironment, as an alternative source of essential amino acids to sustain tumour cell proliferation. Their results show that the availability of extracellular GSH can alter sensitivity to different treatments, or even confer resistance to drugs that block the uptake of these amino acids, with the implications that entails. Another important aspect of their research is that, for this system to function, the correct activity and coordinated action of the various enzymes involved in its complete breakdown are required, highlighting the complexity of these pathways and the ability of tumour cells to adapt and activate alternative metabolic routes.