Cell 'Addiction' to Growth Factors May Help Spur Cancers

Cell 'Addiction' to Growth Factors May Help Spur Cancers
THURSDAY, Dec. 13 (HealthDay News) -- "Addiction" to certain growthfactors contributes to the development of cancers caused by epigeneticchanges, such as the inappropriate activation of a normally silent gene,scientists say.
The team of Johns Hopkins University researchers believe that blockingthis addiction might help prevent cancer growth.
They compared mouse cells with only one copy of the IGF-II(insulin-like growth factor two) gene activated to mouse cells with bothcopies of IGF-II activated. Normally, only one copy of the IGF-II gene isactivated.
In humans, activation of both IGF-II genes has been linked with afivefold increased risk of intestinal tumors.
Mouse cells with one activated copy of the IGF-II gene responded tonormal doses of IGF-II growth factor and recovered within 90 minutes. Thecells with both copies of the IGF-II gene responded to the smallest dosesof growth factor and stayed that way for more than 120 minutes.
Working with mice bred to develop colon cancer, the researchers thenadministered a drug that blocks the cell's ability to respond to IGF-IIgrowth factor. The mice developed 70 percent fewer precancerous lesionsthan untreated mice.
"Finding the molecular mechanism behind cancer development allowed usto use a specific drug to actually take care of these risky cells beforethe animal developed cancer. It's making us think about cancer preventionin a whole new way," Dr. Andrew Feinberg, professor of medicine, oncologyand molecular biology and genetics, and director of the Epigenetics Centerat Hopkins, said in a prepared statement.
"If this is transferable to people, it could be really exciting,"Feinberg said. "It means we might be able to do something about at-riskcells before cancer develops and treat these cells biochemically, andspecifically, rather than using current drugs that are nonspecific andkill everything in their path."
The study was expected to be published online next week in the journalProceedings of the National Academy of Sciences.
More information
The U.S. National Cancer Institute has more about cancer genetics.