University of Mississippi researchers say they have created the first-ever mammalian model of how alcohol consumption spurs tumor growth, showing that even moderate drinking resulted in larger and more robust tumors.
The research provides the first mammalian model of the links between alcohol, VEGF, and tumor growth, said Wei Tan, the study's lead author. The study increases understanding of how alcohol over-stimulates production of vascular endothelial growth factor (VEGF) -- a substance that the body needs, but which can be harmful when there is too much of it.
The new mouse model could lead to a way to block VEGF over-production, a step that could reduce the incidence of cancer and has important implications for cancer education and prevention. Wei Tan, Megan Shparago, Amelia P. Bailey and Jian-Wei Gu of the University of Mississippi Medical Center will present "Moderate alcohol intake stimulates tumor angiogenesis and expression of vascular endothelial growth factor (VEGF) in a mouse model," at the Experimental Biology Conference 2006, April 1-5 in San Francisco.
The study earned Tan a Caroline tum Suden/Frances A. Hellebrandt Professional Opportunity Award from the American Physiological Society (APS) for exemplary research. The presentation was part of the scientific program sponsored by APS.
Researchers develop mouse model
Unlike studies which use alcohol that would be the equivalent of high consumption in humans, the researchers gave mice a more moderate dose -- the equivalent to 2-4 glasses of alcohol per day.
Six male mice received 1% alcohol in their drinking water for eight hours each night during the four-week experiment, Tan said. The six mice in the control group received plain water. In the second week, the researchers injected the mice, both experimental and controls, with mouse melanoma. They ended the experiment after four weeks.
According to Tan, the tumors of the mice that ingested alcohol:
- were nearly twice as heavy compared to the mice that did not have alcohol
- showed a dramatic increase in new micro-vessels, that is, blood vessels that cannot be seen with the naked eye, such as capillaries
- were nearly twice as dense with blood vessels
- showed a significant increase in VEGF
Alcohol long identified as cancer risk "It's very important to have a model of how to prevent cancer," and this study provides that model, Gu said. "Epidemiologists have recognized alcohol as a risk factor for cancer for 100 years," but this study examines how that happens.
The mouse study builds on an earlier study with chicks that showed alcohol consumption increased the expression of a protein known as VEGF. VEGF fuels tumor growth by spurring the development of blood vessels in cancer cells that might otherwise die.
Normally, the immune system can kill off small tumors. However, when they grow large enough the body can no longer fight off the tumor cells. This is why angiogenesis is so important, Gu said.