Cover Story SidebarSlippery Path A special kind of fat can change cell signaling
pathways and block cancer in animals.by JANE M. SANDERS
CANCER CELLS WANT to live forever, and, in fact, they lose the ability to die on their own
as normal cells do. Georgia Tech Professor of Biology Al Merrill wants to figure out how to fix them.
photo by Gary Meek ![]()
Biology graduate students Jia Wei, left, and Chris Haynes use mass spectrometry to explore a potential link between vitamins, lipids and cancer. (300-dpi JPEG version - 796k)
To that end, Merrill is applying his expertise in cell signaling the processes cells use to let information in from the outside to induce intracellular changes ranging from nutrient handling to cell division, and even cell death.
He focuses on a group of signaling molecules called sphingolipids, which work at the intersection where cells decide whether to grow or die.
“Sphingolipids are mostly involved in cell structure and signaling,” says Merrill, who holds the Smithgall Chair in Molecular Cell Biology. “They help define the cell membrane a functional wall that interacts in specific ways with the cell surface proteins and other components. These interactions often turn proteins on and off.”
photo by Gary Meek ![]()
Biology graduate student Chris Haynes and other researchers at Georgia Tech and Emory University are testing the suppression effects of sphingolipid analogues on human prostate cancer cells in mice. Preliminary results are promising. Here, Haynes inspects samples ready for mass spectrometry testing. (300-dpi JPEG version - 558k)
Also, cells use sphingolipid molecules to receive extracellular stimuli that tell the cell to change its behavior. “This signaling pathway is very important to a cell’s life cycle,” Merrill explains. “If it is interrupted by an enzyme-induced remodeling of the cell membrane, cancer may result.”
About 10 years ago, Merrill hypothesized that foods containing sphingolipids, a special kind of fat if delivered via natural digestion in the right amounts and combinations could enter the body and tap the relevant signaling pathway.
photo by Gary Meek ![]()
Just as scientists cracked the human genome, researchers at Georgia Tech are helping develop mass spectrometry methods to identify and quantify all the small molecules in cells collectively called the “metabolome.” (300-dpi JPEG version - 828k)
Merrill and his collaborators have shown that this process could normalize cell function and block several types of cancer colon, breast and prostate in several animal models.
“We know we can change the signaling pathway with this molecule,” Merrill says. “We can do it in mice, and we hope to do it in people someday.” While animal studies continue, Merrill and his research team are beginning to pursue the steps necessary for FDA approval of human trials using sphingolipids.
For now, Merrill is testing the suppression effects of sphingolipids on human prostate cancer cells in mice with a team of investigators that includes Cameron Sullards at Georgia Tech and Professors Dennis Liotta, Dirck Dillehay, David Pallas and Frank McDonald at Emory University.
Funded by a National Cooperative Drug Discovery grant from the National Cancer Institute, the researchers are moving away from the difficult-to-control diet-based delivery of sphingolipids to drug-based intervention. Preliminary results from tests of sphingolipid analogues are promising, Merrill adds.
For more information, contact Al Merrill at 404-385-2842 or al.merrill@biology.gatech.edu.
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Last updated: July 7, 2004