The Princess Margaret “Transformers”

19 THE TRANSFORMERS • TECHNOLOGY ISSUE CRISPR: GENETIC ENGINEERING LIQUID BIOPSY: THE ANSWER IS IN YOUR BLOOD What if your blood could predict your response to cancer treatment? Dr. Suzanne Kamel-Reid Head, Laboratory Genetics, UHN, has been exploring how that question applies to lung cancer patients since 2016. The results of her study, co- led by Dr. Ming-Sound Tsao, Senior Scientist, and Dr. Tracy Stockley, Associate Director, Laboratory Genetics with The Princess Margaret, used blood to predict the presence of a mutation in tissue to optimize treatment. “We’ve been able to optimize and validate a simple blood test, and now implement it clinically. We believe we are the first lab in Canada to offer this to our patients,” says Dr. Kamel-Reid. In his role as UHN’s Executive Vice-President of Science and Research, Dr. Brad Wouters pays close attention to new technologies and their potential for cancer research and treatment. Today, he’s particularly excited by a technique based on a fundamental discovery of how bacteria defend themselves against virus infections, known as CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). CRISPR has demonstrated its potential as a tool for editing the genome (the complete set of genes) in any organism, including humans. Scientists can make changes to the genome, enabling them to study gene function and modify the genome to target disease. Dr. Wouters explains that CRISPR is already capable of manipulating genes to understand their function or their importance in tumours. “We can sequence the entire genome of a cancer cell in just a few days. CRISPR allows us to selectively mutate any gene in that tumour and test their importance on drug sensitivity or other important functional features of the tumour.” With that information, doctors can rule out treatments that are likely to fail and focus on the ones with the best chance of success. “These are approaches scientists only dreamed about a few years ago,” Dr. Wouters explains. He praises the speed and efficiency made possible by CRISPR. “Someone can be trained in a lab in a couple of months, and then be knocking out genes or changing mutations in a matter of weeks.” Samples were studied at laboratories across the country, including Ontario, British Columbia, Alberta, Quebec, and Nova Scotia. “Tumours shed cells and those cells release DNA, and we are looking for that DNA. It’s at very low levels, so you have to have technology that can detect it very sensitively,” says Dr. Kamel-Reid. As of October 2017, this liquid biopsy test is being offered to patients across Ontario. Dr. Kamel-Reid says the same non-invasive methodology could also be used to test for mutations in other cancers. PRECISION GENOMICS MEDICINE