An experimental drug that blocks an essential cell protein could be used to treat Wilms tumour, a childhood cancer that affects the kidneys.

IGF1R plays a key role in creating new tumour cells and keeping them alive. The scientists showed that targeting this protein in mice halted the production of new cells, and eventually killed existing cancer cells.

IGF1R-blocking drugs have already been developed and are showing promise in clinical trials for other cancer types, both alone and in combination with chemotherapy drugs. Using Wilms tumour cells, the team showed that combining IGF1R-blocking drugs with chemotherapy may also work for this disease.

How effective the treatment was depended on the activity of the protein, which sends signals to Wilms tumour cells – the more active the protein, the more effective the treatment.

The same team, led by the ICR’s Dr Chris Jones, previously found that tumours with extra copies of the IGF1R gene are linked to a significantly worse outcome for patients.

The research also showed the importance of testing drugs in cells grown in the organ from which the tumour originated, to provide the same environment.

The researchers used sophisticated techniques designed for testing new treatments and understanding cancer. When tumours were grown outside the kidney, they did not look like Wilms tumours and did not respond to the drug. But, when the cells were grown in the kidneys, the tumour cells looked exactly as they do in patients and responded well to the drug.

The study was published in the journal PNAS