Researchers at the Alpert Medical School have identified a new factor in cell growth that could aid scientists seeking to cure cancer and other diseases caused by cellular malfunction.
It's too early to know how the findings will translate to biomedical applications, but the discovery sheds light on how cells multiply.
"These findings may provide fresh approaches to (treating) a variety of disorders," said Alan Rosmarin MA'98, associate professor of medicine and the study's leader.
Working with Zhongfa Yang MS'04 PhD '05, a research fellow at Rhode Island Hospital and instructor at the Med School, Rosmarin and his team discovered that a transcription factor known as GABP - previously not considered crucial to cell growth - in fact plays a major role in cell division.
Biologists at Rosmarin's Rhode Island Hospital lab shut off GABP production in cells that were reproducing normally. What the scientists observed was startling - as soon as the cells became GABP-deficient, they stopped dividing.
"We showed that if we take away GABP, cell growth comes to a screeching halt," Rosmarin explained.
By a series of tests, the researchers concluded that GABP not only contributes to cell growth but also single-handedly initiates cellular reproduction.
Rosmarin's team - which included Rhode Island Hospital research associate Stephanie Mott - worked on the project for six years. They published their findings earlier this month in the scientific journal Nature Cell Biology.
Yang, who coordinated the experiments and was the lead author of the journal article, said previous understandings of cellular reproduction left some questions unanswered.
"This alternative pathway (for cell growth) will explain the contradictions in the previous theory," he said.
Whether the discovery will open the door to practical medical treatments depends on how precisely scientists are able to manipulate the GABP level in human cells. The challenge for researchers is to find a method of reducing GABP without eliminating it entirely.
Currently, by RNA-silencing, scientists can lower levels of GABP by turning off its coding gene, but the process is imprecise - scientists cannot control exactly how much GABP production is diminished. Lowering levels of GABP could keep cancer from spreading, but completely shutting off production would kill healthy cells as well as cancerous ones.
"You have to fine-tune this protein expression," Yang explained.
The key to combating other diseases may involve the opposite approach: boosting levels of GABP. Rosmarin, who is the director of clinical oncology research for the Rhode Island healthcare provider Lifespan, said the protein could also have applications for stem cell biology. Stimulating production of GABP may also allow scientists to re-grow muscle tissue, which can help treat diseases such as muscular dystrophy.
"I don't want to suggest that these treatments are around the corner, because they are not," Rosmarin said. "But that doesn't mean that, if we can find ways to manipulate the system, we couldn't come up with something."
