Researchers identify Achilles heel of common child...( BOSTON Mass. (Oct. 19 2008) Researc...)

BOSTON, Mass. (Oct. 19, 2008) Researchers have discovered a mechanism for the rapid growth seen in infantile hemangioma, the most common childhood tumor.

The tumors, which are made up of proliferating blood vessels, affect up to 10 percent of children of European descent, with girls more frequently afflicted than boys. The growths appear within days of birthmost often as a single, blood-red lump on the head or facethen grow rapidly in the ensuing months. The development of infantile hemangioma slows later in childhood, and most tumors disappear entirely by the end of puberty. However, while the tumors are benign, they can cause disfigurement or clinical complications. This new research offers hope for the most severe of these cases, pointing at a potential, non-invasive treatment for the condition.

These findings, the result of a collaboration between scientists from Harvard Medical School and the Harvard School of Dental Medicine, Children's Hospital Boston, and the de Duve Institute at the Catholique University of Louvain in Brussels, will be published October 19 in Nature Medicine.

In this study, researchers looked at tissue isolated from nine distinct hemangioma tumors. They found that the endothelial cells that lined the affected blood vessels were all derived from the same abnormal cell. Like other tumors, hemangiomas are caused by the abnormal proliferation of tissue. Since no other type of cell within the tissue displayed the same self-replicating tendency, the scientists concluded that the endothelial cells were the source of the tumors' growth.

Looking further, the team discovered that the endothelial cells behaved as if they were activated by a hormone called vascular endothelial growth factor (VEGF). VEGF usually binds to a specific receptor, one that sits on the outskirts of the cell and prevents VEGF from telling the cell to proliferate. However, the researchers found that at least two gene mutat
'/>"/>