MIT scientists and colleagues have found a way to create in the lab large amounts of cancer stem cells, or cells that can initiate tumors. The work, reported in the August 13 issue of Cancer Cell, could be a boon to researchers who study these elusive cells. Labs could easily grow them for use in experiments.
The findings also contradict an assumption about the trajectory of cancer cells. According to current cancer models, any normal cell can evolve toward a malignant state through a series of alterations, including mutations. Given the right alterations, any cell could eventually acquire the ability to invade other tissues.
But the new study suggests that some normal cells are more prone to become tumor-initiating and have a higher potential to metastasize, or spread to other tissues.
According to the researchers involved in the current work, in some ways certain tumors resemble bee colonies. Each cancer cell in the tumor plays a specific role, and just a fraction of the cells serve as "queens," possessing the unique ability to maintain themselves in an unspecialized state and seed new tumors. These cells can also divide and produce the "worker" cells that form the bulk of the tumor.
These "queens" are cancer stem cells, and they are the cells recently created by MIT biology professor and Whitehead Institute Member Robert Weinberg and colleagues. They did so by isolating and transforming a particular population of cells from human breast tissue. After being injected with just 100 of these transformed cells, mice developed tumors that metastasized.
"The operational definition of a cancer stem cell is the ability to initiate a tumor, so these are cancer stem cells," said Weinberg.
Illustration: Whitehead Institute for Biomedical Research.
MIT News (08/13/07)
Whitehead Institute for Biomedical Research (08/13/07)
The Register/UK (08/14/07)
United Press International (08/15/07)
Science Daily (08/15/07)
Dental Plans (08/17/07)
Cancer Cell Abstract (Cancer Cell, Vol 12, 160-170, 14 August 2007)