Genes Identified In Infantile Hemangioma, The Most Common Childhood Tumor

For the first time in history, researchers 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, have identified the genes involved in infantile hemangioma, the most common childhood tumor. The study of these genetic abnormalities was published in the October 19th 2008 issue of the journal Nature Medicine.

Researchers investigated 9 different hemangioma tumor tissues. They found that certain cells within the tumor (called endothelial cells) were originating from abnormally dividing cells.

By further investigating those endothelial cells, researchers were able to see that they were activated by a hormone called vascular endothelial growth factor (VEGF). VEGF usually docks on to a receptor that prevents it from causing a cell to proliferate.

However, the researchers found that at least two gene mutations were able to trigger a series of biochemical events that ultimately affected these receptors, allowing VEGF to trigger abnormal growth of these cells. Definitely, those two mutated genes were involved in the unchecked growth of the endothelial cells.

According to the authors, learning more about the basic genetics of infantile hemangioma, opens new therapeutic options. Any therapy that targets vascular endothelial growth factor, that is an anti-VEGF therapy, could help infants with these tumors, especially those where clinical complications may affect their quality of life.

Although benign, ten percent of infantile hemangioma sufferers experience problems such as:

*Psychological stress because of social challenges brought on by disfigurement

*Physical complications caused by large tumors

*Obstruction of vision

*Problems with respiration

Anti-VEGF therapies, that is therapies that block the production of VEGF, have been applied successfully for other medical problems such as macular degeneration and certain types of cancer. At the present time anti-VEGF is not approved for hemangioma. But the results of this study will undoubtedly lead some to push for clinical trials to test the efficacy and safety of ant-VEGF therapies on infantile hemangioma.

Interesting enough, infantile hemangioma usually disappears when children reach puberty. Why does this happen? There's no consensus answer. Finding out may be the key to treating infantile hemangioma at its early ages. The study mentions that the research group is directing its effort to elucidating why infantile hemangioma tumors regress in puberty.

Bjorn R. Olsen. 2008 (October). Nature Medicine