Stem Cells May Be at Root of Cancer
New Research May Explain Why So Many Tumor-Fighting Treatments Now Fail
WebMD News Archive
April 20, 2007 (Los Angeles) -- Are most current cancer treatments -- as well as many in development -- aimed at eradicating the wrong cancer cells?
That's the position of some leading researchers, who say that cancer is, fundamentally, a stem cell problem -- and that therapy should be targeted at so-called cancer stem cells.
"The models we currently use to develop cancer treatments are fundamentally flawed," says Max Wicha, MD, director of the University of Michigan Comprehensive Cancer Center in Ann Arbor.
"Most approaches up to now are targeting the wrong population of cancer cells," which explains why so many fail to produce a cure, he tells WebMD.
At the annual meeting of the American Association for Cancer Research here this week, Wicha moderated a session during which researchers discussed new discoveries suggesting that stem cells in leukemia, breast, and colon cancer are at the root of many tumors.
A Primer on Cancer Stem Cells
All stem cells -- regardless of their source -- share some general properties: They can reproduce and make exact copies of themselves, they live longer than ordinary cells, and they can give rise to other cells in our bodies.
Embryonic stem cells are a hot, if controversial, area of research. They are at such an early stage of development that they have potential to become many different types of cells, including those of the heart or brain, for example.
Adult stem cells, on the other hand, are generally limited to differentiating into cell types of their tissue of origin. Under typical conditions, for example, adult stem cells in liver tissue can only form liver cells, Wicha explains.
In labs worldwide, scientists are working furiously to figure out how to use both embryonic and adult stem cells to produce virtually unlimited quantities of healthy cells to replace the damaged ones in patients suffering from disorders ranging from Alzheimer's to Parkinson's disease.
Cancer stem calls are a perversion of other adult stem cells. "They are cells that have the ability to reproduce themselves and develop into cancer cells," Wicha says.
A New Model for Cancer
Wicha says that the current model of what causes cancer assumes that cells become malignant after a series of mutations disables their genetic control system.