November 20 (HealthDay News) -- New research on mice suggests inhibiting a protein that allows certain tumor cells to refuel may prove to be key to cancer-fighting treatments.

A study by Pierre Sonveaux and colleagues at Universit catholique de Louvain, in Belgium, found that tumor cells use different fuel sources depending on whether they are in regions rich in oxygen or deprived of oxygen, called hypoxic regions. The researchers found that cells in hypoxic regions use glucose to generate energy, but well-oxygenated tumor cells instead use lactate.

The findings were published in the Nov. 20 online issue of The Journal of Clinical Investigation.

By inhibiting the protein MCT1, which takes in the lactate to convert it to fuel, in the well-oxygenated cells, they switched to using glucose. This upset the symbiotic relationship between the hypoxic and well-oxygenated tumor cells, causing decreased tumor growth in two mouse models.

As the hypoxic tumor cells became deprived of the glucose now going to the oxygen-rich tumor cells, they became sensitive to irradiation.

SOURCE: The Journal of Clinical Investigation, news release, Nov. 20, 2008