Undruggable?

Professor Michael Ohh and postdoctoral fellow Severa BundaProfessor Michael Ohh and postdoctoral fellow Severa Bunda

A notorious family of proteins called “Ras” is involved — directly or indirectly  — in virtually all cancers.

With the role of triggering cell growth, Ras can get carried away and spur uncontrolled growth. It is mutated in over 90 per cent of pancreatic cancers, one of the deadliest.

Scientists have struggled to find ways of stopping Ras, leading it to be deemed an “undruggable” protein. But by tapping into the “social networks” at play among proteins, researchers at the University of Toronto may have found a way. They’ve identified another player, which acts as an enabler to Ras, prodding it to misbehave.

The late University of Toronto Molecular Genetics Professor and pre-eminent cancer researcher Tony Pawson discovered how this type of enabler influences the behaviour of other proteins.

More recently, Laboratory Medicine and Pathobiology, and Biochemistry, Professor Michael Ohh targeted the enabler protein in an aggressive type of brain cancer in mice. By muzzling the enabler, he was able to essentially turn off Ras — like flipping a switch. The tumours shrunk by over 80 per cent.

The next steps are to treat mice with human pancreatic tumours and if successful, move on to human clinical trials.

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