A Clear Signal

By David McLaughlin

They say communication is everything. In fact, it’s critical right down to the cellular level. Cells control their behaviour and influence each other through chemical signals. When they miscommunicate, we can become ill.

So, when a team led by Late Professor Tony Pawson from the Department of Molecular Genetics identified how cell receptors transmit the signals that instruct cells to change, it touched on nearly every aspect of medical research and the treatment of disease.

Scientists had long known that cells communicated, but did not understand the exact mechanism. Pawson’s team discovered that a certain protein structure plays a critical role in transmitting cancer-inducing signals in malignant cells.

The structure — which Pawson called the SH2 domain — exists on the surface of every cell membrane. This knowledge has led to new drugs that can “turn off” cancer cells and stop the proliferation of some types of the disease.

Pawson, whose colleagues often referred to him as a "cell biology revolutionist," published more than 300 scientific articles, and he is one of the most cited biomedical scientists in the world.

Pawson died at the age of 60 in 2013. Only months before his death, his lab had achieved a new breakthrough in understanding cell signaling. The new discovery shed light on how normal cells communicate and control their growth — insights that could improve the selection of cancer drug therapies in clinical trials, and improve drug resistance in cancer patients.

“We’ve been studying the proteins involved in this signalling pathway for over 20 years,” said Pawson, also a scientist at Mount Sinai Hospital’s Tanenbaum-Lunenfeld Research Institute. “What is exciting about these findings is that they provide exquisite detail on how these proteins interact with each other and the exacting control that is placed on them to ensure accurate transmission of a growth signal.”

Pawson received the Michael Smith Prize in Health Research from the Canadian Institutes of Health Research, the Gairdner Foundation International Award and the Heineken Prize from the Royal Netherlands Academy. In 2008, he was named a Kyoto Prize Laureate, the first Canadian scientist to hold this title.