Dr. Tak Mak and scientists at The Campbell Family Institute for Breast Cancer Research at Princess Margaret Hospital have discovered the role of two “cousins” in the genetic family tree of cancer development.

The findings, published online today in the journal Genes and Development, plant the seed for a critical new branch of scientific inquiry, says Dr. Mak, principal investigator. Dr. Mak, Director of The Campbell Family Institute is also a Professor, University of Toronto, in the Departments of Medical Biophysics and Immunology.

The cousins are proteins related to the gene p53 family – the patriarch known for two decades to be the master gatekeeper that controls all cancer development. When gene p53 is defective, it loses its ability to regulate healthy cells and suppress cancer.

“Until now, we thought these cousins (TAp73 protein isoforms) were not involved in cancer. Our results prove that they are. This is fundamental to understanding every human cancer and furthering the science.”

In the lab, Dr. Mak and his team challenged traditional thinking about the role of these proteins. “Before, scientists studied only whether these proteins were present or absent. We decided to study how they interact with each other and discovered that they actually have a split personality. When we turn one ‘on’ or ‘off’, the other changes behavior and becomes part of the cancer-causing process. The key is understanding the ratio of the interaction.”

“The next step is to understand how the ratio affects cell division that leads to human cancer,” says Dr. Mak, whose work was supported by the Canadian Institutes for Health Research.

About Dr. Tak Mak
Dr. Tak Mak is a pre-eminent Canadian scientist and internationally acclaimed immunologist, renowned for his 1984 discovery of cloning the human T-cell receptor. His discoveries have made an enormous contribution to the understanding of immunity and especially as it relates to cancer and HIV/AIDS. Dr. Mak, Director of The Campbell Family Institute for Breast Cancer Research at Princess Margaret Hospital, University Health Network, has published more than 600 articles and received more than 3,000 citations in leading scientific journals. He is also Professor, University of Toronto, in the Departments of Medical Biophysics and Immunology.

His honours include the Gairdner Foundation International Award, the Emil von Behring Prize, the E.W.R Steacie Prize, and the General Motors Research Foundation Alfred P. Sloan Prize. Dr. Mak is an Officer of the Order of Canada, a Member of the Order of Ontario and recipient of the Premier’s Summit Award, and a Fellow of the Royal Society of Canada and the Royal Society of London.

About The Campbell Family Institute for Breast Cancer Research
The Campbell Family Institute for Breast Cancer Research at Princess Margaret Hospital brings together an elite team of cancer researchers, scientists, clinicians and staff dedicated to the ultimate goal of conquering breast cancer by leveraging basic, translational and clinical research into dramatic breast cancer breakthroughs.

About Princess Margaret Hospital
Princess Margaret Hospital and its research arm Ontario Cancer Institute - which includes The Campbell Family Cancer Research Institute and The Campbell Family Institute for Breast Cancer Research - have achieved an international reputation as global leaders in the fight against cancer. Princess Margaret Hospital is a member of University Health Network, which also includes Toronto General Hospital and Toronto Western Hospital.

Source: University Health Network (UHN)