As part of the Canadian Institutes of Health Research (CIHR) Team Grants: Bringing Biology to Cancer Prevention, CHUM Research Centre (CRCHUM) researcher Vikki Ho has been awarded $2 million over five years.

Her project “Environmental eXposure Profiling for Signatures of Early ColoRectal Cancer (EXPOSE-CRC)” brings together an interdisciplinary team co-led by Drs. Vikki Ho (CRCHUM), Lee-Hwa Tai (Université de Sherbrooke), Bouchra Nasri (Université de Montréal) and Daniel von Renteln (CHUM), uniting public health scientists, molecular biologists, clinician researchers and patient partners around a common goal: to better understand how modifiable factors contribute to the onset of colorectal cancer.

Better understanding colorectal cancer

The first component of EXPOSE-CRC follows an exposome approach. The concept of the exposome refers to all environmental factors, including chemical, physical, biological, lifestyle and psychological stressors, an individual experiences throughout their lifetime. It aims to identify individual or combined modifiable risk factors capable of predicting the future diagnosis of colorectal cancer. To do so, the team is drawing on the national study Canadian Partnership for Tomorrow's Health, which gathers data on the lifestyle, health and environmental exposures of hundreds of thousands of people in Canada.

The second component of the project, in collaboration with an interdisciplinary team including researchers from Université de Sherbrooke and McGill University/Lady Davis Institute, explores the initial biological changes associated with these modifiable factors. Human colonic organoids—small 3D structures derived from biopsies of patients undergoing a screening colonoscopy—will be exposed to the identified risk factors. This model will enable the team to monitor how these exposures influence the early stages of cellular transformation at the molecular level.

Finally, the team hopes to establish a cohort of patients undergoing screening colonoscopies at the CHUM to gather information on exposures and to measure genetic, epigenetic and microbial markers in normal-appearing colonic tissue. The goal is to examine the influence of individual or combined risk factors on a set of biomarkers present in tissue samples in order to determine whether these biomarkers predict the presence of precancerous polyps.

“These goals combine the strengths of both population health and molecular biology research, moving beyond the current paradigm in which these fields work separately, explains Vikki Ho. Our results will guide and prioritize future public health strategies aimed at reducing the burden of colorectal cancer.”

About the study

EXPOSE-CRC brings together an interdisciplinary team whose complementary skills are essential to the success of this ambitious program. The team combines expertise in epidemiology, exposure science, biostatistics, genomics, molecular biology, immunology, bioinformatics, oncology, surgery and social epidemiology. Key members include patient partner and colorectal cancer survivor Natalie Lipshultz (British Columbia), as well as Drs. Michael Witcher (McGill University), François-Michel Boisvert (Université de Sherbrooke), Marie-Josée Boucher (Université de Sherbrooke), Marie Brunet (Université de Sherbrooke), Yves Collin (Centre hospitalier universitaire de Sherbrooke), Sophie Marcoux (Université Laval), Jérôme Lavoué (Université de Montréal), Arielle Elkrief (CRCHUM), Roy Hajjar (CRCHUM) and Manuela Santos (CRCHUM).