In a biological rendition of fiction's Strange Case of Dr. Jekyll and Mr. Hyde, researchers from the Mayo Clinic campus in Florida and Harvard Medical School have found that a protein thought to protect against cancer development can actually spur the spread of tumors.
The scientists, reporting in the Sept. 3 issue of Molecular and Cellular Biology, found that FOXO3a, a transcription factor that regulates gene expression, becomes active when growing cancer cells begin to starve. Their research suggests that this protein then turns on molecular switches that allow the cancer cells to invade surrounding tissues.
"This is a complete reversal of what everyone thought about FOXO3a - that we should find a way to activate this transcription factor so as to fight cancer growth," says cancer biologist Peter Storz, Ph.D., the study's lead investigator from Mayo Clinic in Florida.
Findings from the study, which was funded in part by the Florida Department of Health, illustrate the growing recognition in the research community that proteins can play multiple roles with respect to tumor progression, he says.
"More and more we see that, when it comes to cancer, proteins can have split personalities," Dr. Storz says. "Proteins once firmly believed to be tumor suppressors that protect against cancer development have recently been found to act as oncogenes, or cancer promoters, in certain cancers and in some biological circumstances. We now understand that proteins behave in different ways, depending on the cellular context."