Over the past four decades researchers have made great progress in the War against Cancer, a disease that one in three women and half of men are at risk of developing during their lifetime.
Cancer researchers have learned to sequence cancer cells’ genomes, scan the cells for suspicious gene activity, profile the contents for symptomatic proteins and watch them grow in a petri dish.
What they haven’t been able to do, until now, is track cancer cells as they form new tumors.
A new article in Nature has added support to the idea that tumor growth is driven by a small subset of “cancer stem cells”. The studies, done in mice by three international groups, may be one of the biggest breakthrough in cancer research to date.
If it turns out this compelling but controversial hypothesis is correct for all cancer types, eliminating those cells could be the answer to curing cancer.
Just as ordinary stem cells produce normal tissues, some cancer researchers believe tumor development is fueled by cancer stem cells.
Previous studies have tested this idea by sorting cancer cells into subsets and injecting them into laboratory mice. The idea is, if cells generate new solid tumors they can be classified as cancer stem cells.
But some researchers reject the notion of cancer stem cells altogether.
Critics quickly point out that transplantation alters cells’ natural environment and thus, may change the cells' behavior. These experts say it's possible that cancer cells may act in far more complex ways than those observed.
It’s too soon to know if the results for brain cancer, gastric cancer and skin cancer will hold true for other cancer types, said Dr. Luis Parada, a developmental biologist at the University of Texas Southwestern Medical Center in Dallas, who led the brain study.
But if it does, “there is going to be a paradigm shift in the way that chemotherapy efficacy is evaluated and how therapeutics are developed.”
Parada told Nature that instead of testing to see if a treatment shrinks a tumor, researchers will assess whether it kills the right sorts of cell.