Doctors might soon be able to harness a protein that kills cancerous cells without also attacking healthy ones.

New research uncovers how the molecule works: According to a study in Oncogene, the protein called “Cluster of Differentiation 40” takes advantage of the fact that the malignant cells are under stress, a side effect of their constant multiplying. That type of stress is known as oxidative stress, and can be damaging to cells — even causing disease — in an oxygen-driven process that is similar to how metal turns to rust.

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The cancer cells “have developed protective properties that enable them to cope,” England’s University of Huddersfield said in a statement. “CD40 removes this protection so that the tumour cells die, but because normal cells are not placed under ‘oxidative stress’ they are unharmed by the protein.”

What makes the protein attractive as a potential cancer treatment is how it leaves healthy cells alone — unlike current treatments that eradicate everything in sight, unable to distinguish between disease and host.

“The discovery opens up the potential for highly effective new cancer treatments that are free of serious side effects,” the university said, adding that the research team hopes to start clinical trials on a CD40-based cancer therapy soon.

Source: Georgopoulos NT, Dunnill CJ, Ibraheem K, Mohamed A and Southgate J. A redox state-dictated signalling pathway deciphers the malignant cell specificity of CD40-mediated apoptosis. Oncogene. 2017.

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