Same Disease, Same Treatment—Drastically Different Outcomes
It was while Dr. Sheila Singh, Canada Research Chair in Human Cancer Stem Cell Biology, was in medical school that two little boys with brain tumours—both named Christopher—sowed the first seeds of her interest in research. Both were five years old and treated with the best current therapies. One flourished. The other died. Singh says the boy who died left her a legacy of questions: Why should two small boys with the same disease fare so differently? What is different about each individual’s tumour? As a scientist in McMaster University’s Stem Cell and Cancer Research Institute, Singh now spends her life looking for the molecular and genetic answers to these questions. She’s discovered an abnormal stem cell—the brain tumour initiating cell (BTIC)—that may drive the formation of brain tumours. It’s the first isolation of cancer stem cells in the central nervous system—a discovery with important implications for understanding how brain tumours start. Most important to Singh’s research is the idea that only a small population of cancer stem cells, and not every cell in a brain tumour, is capable of generating and propagating. Current approaches to brain tumours focus on every cell in the tumour rather than on the rare tumour stem cell, and this may explain the poor response of brain tumours to current treatments. Future therapies that target the BTIC could better halt the growth and propagation of tumours. Singh and her team will continue to search for better surface markers for the BTIC, making it possible to isolate the cell even more specifically and easily. Her work will offer insight into patient prognosis, as patients with a higher proportion of BTICs may have a shorter survival and worse prognosis. Her studies will form the basis for future trials of therapy directed against the BTIC.