Researchers are developing a new oxygen-independent therapy for cancer

Tumors often contain areas of oxygen-depleted tissue that often resist conventional therapies. This is because the drugs used in tumors require oxygen to be effective. An international research team has developed a new mechanism of action that works without oxygen: nanocatalysts built into polymers selectively target tumor tissue and deactivate the glutathione that cells need to survive. The group led by Dr. Johannes Karges from the Faculty of Chemistry and Biochemistry at Ruhr University Bochum, Germany, published their findings on October 31, 2024 in the journal Nature Communications.

Why tumors shrink but don’t disappear

“Because tumors grow very quickly, consume a lot of oxygen and their vascular growth cannot necessarily keep pace, they often contain areas that are poorly supplied with oxygen,” explains Johannes Karges. These areas, often in the center of the tumor, often survive treatment with conventional medications, causing the tumor to initially shrink but not disappear completely. This is because the therapeutic agents require oxygen to be effective.

The mechanism of action developed by the Karges team works without oxygen. “It is a catalyst based on the element ruthenium, which oxidizes and disables the naturally occurring glutathione in cancer cells.”

Johannes Karges, Ruhr-University Bochum

Glutathione is essential for the survival of cells and protects them against a wide variety of factors. When it is no longer effective, the cell deteriorates.

The compound accumulates in tumor tissue

All cells in the body need and contain glutathione. However, the catalyst has a selective effect on cancer cells because it is packaged in polymeric nanoparticles that specifically accumulate in the tumor tissue. Experiments with cancer cells and with mice with human tumors, which were considered incurable, proved successful. “These are encouraging results that need to be confirmed in further research,” concludes Johannes Karges. “Yet, much research still needs to be done before it can be used in humans.”