New research suggests that a protein normally credited as a tumor suppressor may actually fuel an aggressive type of cancer, known as acute myeloid leukemia.
The protein, RUNX1, is a transcription factor, meaning it binds to certain DNA sequences and controls which genes are turned on or off. A team of researchers from Cincinnati Children's Hospital Medical Center found that blocking the protein, which plays an important role in regulating the development of blood cells, stopped the development of leukemia cells.
"We got the opposite of what we expected," says lead researcher James Mulloy. "Taking away RUNX1 had very rapid, dramatic effects."
Acute myeloid leukemia is a rare but fast-moving type of cancer that typically affects older people and accounts for just more than 1 percent of all cancer-related deaths. It starts in cells that would normally become blood cells and promotes the rapid growth of abnormal white blood cells.
Because this type of cancer spreads so quickly, it typically requires prompt treatments including chemotherapy, radiation or bone marrow transplants. But those treatments can sometimes be risky and are not always effective, according to the study.
The researchers' findings could provide hope for a more effective treatment in the future, Mulloy says.
Mulloy's colleague Paul Liu, who works at the National Cancer Institute and collaborated on the research, developed a molecule that blocks RUNX1. The team hopes that this finding could be used as a starting point to improve the compound and eventually develop a medicine that could be ingested orally.
"Maybe in 10 years we will have a new tool in our arsenal that will really be effective against these really bad outcome leukemias," Mulloy says.
Mulloy says another significant outcome of the study is the fact that it adds to a growing amount of research that questions how tumor suppressors function in different situations. Certain kinds can both promote cancer growth or inhibit it, depending on their activity levels and what types of cells they interact with.
A recent study from the Moffitt Cancer Center in Florida suggested, for example, that a protein complex that was known to promote cancer growth can also fight off cancerous cells when it is regulated differently.
"I think the scientific field is coming to an understanding that labeling something as tumor suppressor or an oncogene is too simplistic," Mulloy says.