London, Oct 20 : Scientists have discovered how the common childhood tumour, infantile hemangioma, grows rapidly.
Infantile hemangioma, made up of proliferating blood vessels is more frequently found in girls than boys. The tumour growth starts within days of birth-most often as a single, blood-red lump on the head or face-then grow rapidly in the following months. It slows later in childhood, and most tumours disappear entirely by the end of puberty.
But, despite being benign, the tumours can still lead to disfigurement or clinical complications. The new study could lead to a potential, non-invasive treatment for the condition.
The scientists focussed their study on tissue isolated from nine distinct hemangioma tumors and found that the endothelial cells lining the affected blood vessels were all derived from the same abnormal cell.
Just like other tumors, hemangiomas are caused by the abnormal proliferation of tissue. And as the self-replicating tendency was specific to endothelial cells, they were named as the source of the tumors' growth.
Later, the researchers found that the endothelial cells behaved as if were activated by a hormone called vascular endothelial growth factor (VEGF), which usually binds to a specific receptor, one that sits on the outskirts of the cell and prevents VEGF from telling the cell to proliferate.
But, the researchers closed in on at least two gene mutations that could trigger a chain of events that ultimately stymied those receptors, enabling VEGF to trigger unchecked growth in the endothelial cells.
According to study leader Bjorn R. Olsen, the Hersey Professor of Cell Biology at Harvard Medical School and Professor of Developmental Biology and Dean for Research at Harvard School of Dental Medicine, the findings pave the way for new treatment options,
"What the data suggests is that any therapy that is directed against vascular endothelial growth factor - anti-VEGF therapy - is the rational therapy to use in these tumors," Nature quoted Olsen, as sayiing.
The findings may prove to be good news to the many children and families affected by the disorder.
While the majority of cases have little impact on children's lives and many cases go unnoticed, according to estimates 10 percent of infantile hemangioma sufferers experience significant side-effects.
These can include psychological stress brought on by the social challenges of disfigurement, as well as physical complications caused by large, badly-placed tumours that obstruct vision, respiration, or other bodily functions.
Anti-VEGF therapies have already been approved for other conditions, including macular degeneration and certain types of cancer. The next step for Olsen's team is to get approval to test these therapies in clinical trials.
The findings will be published in the latest issue of Nature Medicine.