August 11, 2008

Researchers Hunt Normal Cells That Give Rise to Cancer

MONDAY, Aug. 11 (HealthDay News) -- Learning more about normal cells that give rise to cancer may hold the key to understanding and treating cancer, according to Duke University Medical Center researchers who identified cells linked to a deadly brain cancer.

"Identifying the specific, normal cells that cancer come from can provide critical insight into how cancers develop. This may help us develop more rational and effective approaches to treatment," Robert Wechsler-Reya, an associate professor of pharmacology and cancer biology, said in a medical center news release.

In what's believed to be a first, the Duke team had identified two types of cells in the brain that can give rise to the malignant brain tumor medulloblastoma. It occurs most commonly in children and is treated with a combination of surgery, chemotherapy and radiation, which cause severe side effects.

In order to identify the normal cells associated with medulloblastoma, the Duke researchers and colleagues in Australia created mouse models of medulloblastoma by turning off the patched gene, an important regulator of cell growth in the cerebellum. Specifically, they switched off the patched gene in granule neuron precursors (GNPs), which make one particular type of neuron, or in stem cells, which can make all the different cell types in the cerebellum.

When the patched gene was turned off in GNPs, 100 percent of the mice developed medulloblastoma. When the gene was deleted from stem cells, most of them went on to form normal cell types within the cerebellum.

The findings provide the first definitive proof that medulloblastoma can be triggered in GNPs, the researchers said.

"Simply mutating a gene is not enough to cause cancer. The mutation has to happen in the right cell type at the right time. In the case of patched, GNPs provide the critical context for tumor formation," Wechsler-Reya said.

The study was published in the August issue of the journal Cancer Cell.

More information

The U.S. National Cancer Institute has more about cancer.

-- Robert Preidt
SOURCE: Duke University, news release, Aug. 11, 2008
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