VANCOUVER - Scientists at the B.C. Cancer Agency are trumpeting what they say is an important advance in the study of breast cancer, particularly the role of stem cells as a cause of the disease.
The lead researcher in a study says the work holds the potential to develop better treatments for this major killer in 10 to 15 years.
An article being published in this week's Nature Medicine scientific journal outlines the Vancouver-based research team's success in growing transplanted normal female breast stem cells in mice.
It's considered significant because many investigators believe normal breast stem cells that malfunction are behind breast cancers.
"So if we can understand the way breast stem cells work it might be possible in the future to develop a drug that would be very effective in targeting these cells when they go wrong," said Peter Eirew, lead author of the study and a doctoral student in genetics at the agency's Terry Fox Lab and University of British Columbia.
The study involved taking normal breast stem cells and transplanting them into specially bred mice whose immune systems would not reject the human tissue.
This allowed the stem cells to regrow a complete miniature, milk-producing mammary gland after being transplanted into the immune-deficient mice.
"Stems cells are quite difficult to detect and the way to detect them is to give them a chance to show what they can do," Eirew said Sunday in an interview.
"It's by transplanting that we're able to give stem cells, if they're present, a chance to show themselves by regenerating little milk-producing glands."
The cells are first suspended in a gelatin disc and then the disc is slipped under the kidney capsule of mice that have no immune system.
The mice can't tell the human cells are foreign and so allow them to grow freely. The human stem cells replicate into functional mammary glands fed by a blood supply provided by the mouse.
Eirew said breast stem cells were selected for the study because breast cancer is a major killer among all cancers. But researchers believe malfunctioning stem cells are behind many types of cancer.
"To some extent any techniques that are discovered in breast cancer may well be applicable to other types of cancer as well," Eirew said.
Co-author Dr. Samuel Aparicio said the long-term goal is to learn what makes normal breast stem cells tick and use the information to see what causes them to develop into malignant tumours.
Eirew said the study built on work by Dr. Connie Eaves, director of the Terry Fox Laboratory and a co-author of the paper. Her group published a study in 2006 that identified a similar population of breast stem cells in mice.
Eirew said it's hard to chart a reliable timeline for when this research might pay off in new cancer treatments but suggested work done in the 1990s on the link between blood stem cells and leukemia could provide a yardstick.
"Some 10 to 15 years later we are actually seeing new drugs being applied to treat patients and drugs which are vastly more effective than previous treatments," he said.
