Chemotherapy can undermine itself by causing a rogue response in healthy cells, which could explain why people become resistant,
according to researchers at the Fred Hutchinson Cancer Research Centre in Seattle.
In their study, they looked at fibroblast cells, which normally play a critical role in wound healing and the production of collagen, the main component of connective tissue such as tendons. But chemotherapy causes DNA damage that causes the fibroblasts to produce up to 30 times more of a protein called WNT16B than they should.
The protein fuels cancer cells to grow and invade surrounding tissue – and to resist chemotherapy. It was already known that the protein was involved in the development of cancers – but not in treatment resistance. Around 90% of patients with solid cancers, such as breast, prostate, lung and colon develop resistance to chemotherapy.
Treatment is usually given at intervals, so that the body is not overwhelmed by its toxicity. But that allows time for tumour cells to recover and develop resistance.
The researchers said they hoped their findings will help find a way to stop this response, and improve the effectiveness of therapy.