In 1981, as a young PhD student of Nahum Sonenberg, PhD, at McGill, Prof. Pelletier delved into the intricacies of how the genetic code is used to make proteins, particularly the final step of the process, which is known as mRNA translation. His work revealed the mechanism used by polio and related viruses to hijack the host cell’s mRNA translation machinery. This landmark discovery in molecular biology and virology is highly relevant to the modern quest to design antiviral drugs and RNA therapeutics.

After completing his PhD, Prof. Pelletier joined the laboratory of Professor David Housman, PhD, at the Massachusetts Institute of Technology. There, he immersed himself in genetics, focusing on Wilms’ tumour (WT), a kidney cancer that mainly affects young children. He was involved in the discovery of the WT1 gene, which is frequently mutated in WT. Predating the modern genomics era, this accomplishment was the result of painstaking work using difficult techniques. Prof. Pelletier’s subsequent groundbreaking studies showed how the WT1 protein functions in normal development and how changes in WT1 cause cancer.

In 1991, Prof. Pelletier returned to McGill University to establish his laboratory. Soon after, along with colleagues Philippe Gros, PhD, and Michael Dubow, PhD, he co-founded a biotech company focused on developing a new class of antibiotics, culminating in the FDA approval of the drug Oritancin.

By 2002, Prof. Pelletier had risen to the ranks of full professor and went on to become one of Canada’s top molecular biologists and an international expert in RNA biology and therapeutics. With a passion for drug discovery, he and his team explored the therapeutic potential of new classes of natural and synthetic molecules, discovering and characterizing several drugs, many of them from natural sources, that inhibit a key regulator of mRNA translation known as eIF4A. He showed that these drugs prevent the production of proteins required by cancer cells, important work that enabled ongoing clinical trials of eIF4A inhibitors in cancer patients. Prof. Pelletier was also instrumental in bringing the RNA-guided genome editing technology known as CRISPR/Cas9 to McGill, and in ongoing efforts to exploit the chemical and biological properties of RNA to develop new therapies for cancer and other diseases.

In 2017, Prof. Pelletier was honoured as a fellow of the Royal Society of Canada and in 2019 he was the recipient of the Robert L. Noble Prize from the Canadian Cancer Society for his groundbreaking work in elucidating the initiation and control of protein synthesis.

Prof. Pelletier’s journey in the field of RNA biology and therapeutics is a testament to his unwavering commitment to scientific research and unyielding curiosity. From his self-described upbringing as an army brat in Saint-Jean-sur-Richelieu to his roles as a distinguished professor, co-founder of a biotech company, recipient of numerous awards, and co-founder of McGill’s Centre for RNA Sciences, his life reflects a tapestry of diverse experiences and groundbreaking discoveries.

Our condolences go out to Prof. Pelletier’s family, friends, colleagues and all those whose lives he touched. He will be greatly missed but his legacy will endure.