Pawson, chair of molecular oncology at the Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital in Toronto, died late Wednesday of an undisclosed cause.
His death has stunned and saddened the scientific community both in Canada and abroad, long-time colleagues said Friday.
"Tony's passing represents a profound loss for Canada's scientific community and will be felt throughout the international medical research world," Dr. Jim Woodgett, director of the institute, said in a statement.
"All of us here at Mount Sinai Hospital are deeply saddened. He was an extraordinary colleague, brilliant mind and dear friend. His research team ... has revolutionized our understanding of how cells work and his legacy will always be felt here as we continue to pursue his lifelong dedication to discovery."
Fellow scientist and close friend Alan Bernstein, head of the Canadian Institute for Advanced Research, said Pawson would have been a likely candidate for a Nobel Prize in Medicine or Physiology because his sentinel research laid the groundwork for discoveries by other scientists.
In 1990, Pawson's team first reported on key protein interactions involved in "signal transduction" — or how cells communicate and control each other's behaviour through chemical signals. Miscommunication among cells can give rise to such diseases as cancer, diabetes or heart disease.
"Tony really uncovered a fundamental mechanism by which cells in our body communicate with each other," said Bernstein. "And breakdowns in that mechanism — whether it's in cancer or diabetes or in neurological or embryonic development — quite often involve this mechanism that Tony discovered."
Pawson's insight paved the way for the development of designer medications such as Gleevec, a drug that locks out an abnormal cell signal that causes chronic myelogenous leukemia, a form of blood cancer. Other drugs based on the same principle are also in the works.
"He's just been transformative in Canadian science and really had an impact on how patients are treated currently and will be in the future," said Sian Bevan, director of research at the Canadian Cancer Society, which helped fund much of his work.
"It's very shocking news," she said of his death, "and we're really saddened that we've lost one of our great scientists in the family."
Michael Wosnick, former head of research at the Cancer Society, called Pawson's passing a "huge loss" for the global scientific community and for Canada.
"One of the things he did for Canada, ironically, was stay in Canada. This is a guy who could have written his own ticket anywhere ... and the fact that he chose to stay here speaks volumes," said Wosnick.
The British-born Canadian was the recipient of numerous awards, including Japan's "Nobel" — the Kyoto Prize — in 2008. He was also honoured with the Wolf Prize in Medicine and the Gairdner Foundation International Award, as well as being named by the Queen in 2007 to the Order of the Companions of Honour.
"We were anticipating one day a Nobel Prize for this guy," said Wosnick. "Tony certainly would have been the odds-on favourite to be the next Canadian (to win).
"I think Tony should have won the Nobel and I think would have in time," agreed Bernstein, who described his friend — a fly-fishing aficionado away from the lab — as being passionate about science and "pretty well everything."
"He was a lot of fun to be around. He was exceptionally bright and articulate. He cared about his family deeply."
Pawson's wife Maggie died of lung cancer two years ago, and Bernstein and others said he had never fully recovered from her loss. He is survived by two adult children and a stepson.
Despite his international stature in the scientific world, Pawson was described repeatedly as unpretentious, even humble.
"He was very proud of his work, he was very proud of the people in his lab who did the work," said Bernstein, adding that Pawson trained numerous scientists who have gone on to research institutions around the world.
"But in terms of his overall place in the universe, yeah, I think he was a modest guy."