Published on September 2, 2009 at 4:47 AM
Ewing's sarcoma is the second most common bone cancer in children and adolescents. The five-year survival rate is considered poor at about 30 percent if the cancer has spread by the time it is diagnosed, and there is an even poorer prognosis for patients who have suffered a relapse.
For this study, researchers focused on an abnormal protein known as EWS-FLI, which is found in most Ewing's sarcoma tumors. What they discovered is that EWS-FLI causes increased amounts of the GSTM4 gene - and the protein it produces - to be expressed in tumors, a previously unknown effect that led them to make the connection between poor outcomes and high levels of GSTM4. The discovery was made by focusing on repetitive DNA sequences called microsatellites. Microsatellites are sometimes referred to as "junk DNA" because they are not thought to have a normal role in the genome. By examining how EWS-FLI interacts with certain microsatellites, Lessnick and his team were able to identify GSTM4.
Lessnick says the next step in research is to focus on testing and treatments that may lead to better survival rates in patients. "Personalized medicine is the next frontier in the battle against cancer," he says. "We now know all cancers are not the same. By focusing on how these proteins are expressed in individual tumors, we may soon be able to offer the treatment that will work best for each patient, and that could lead to higher cure rates," he says.