Canadian researchers say they have identified a protein that may play a critical role in breast cancer cell growth.The study, published in the Journal of Biological Chemistry, says the protein -- known as ARF1 -- is also involved in the spread of tumors.

"Until now, ARF1 has been associated with harmless albeit important housekeeping duties of cells," senior study author Audrey Claing of the University of Montreal says in a statement. "The University of Montreal and the University of Alberta team is the first to characterize the role of ARF1 in breast cancer."

Claing and colleagues used invasive breast cancer cell lines to study ARF1's role. These cells are sensitive to a particular growth factor, called epidermal growth factor, which has been shown to stimulate tumor growth and invasion.

The researchers suggest epidermal growth factor works through ARF1 in these cells. In addition, when ARF1 activity was chemically blocked, breast cancer cell migration and growth was reduced. Conversely, when ARF1 was overproduced in these cells, their movement was enhanced."Taken together our findings reveal an unsuspected role for ARF1 and indicate that this small protein may be a potential therapeutic target for the treatment of invasive breast cancers," Claing said.