"Since each of these gene expression signatures is regulated by a specific pathway, these genes essentially report to us which pathway might be causing the cancer," Gilbertson said. "Using this information, researchers can use drugs to block that pathway."
The St. Jude team proved that the principle of identifying genes linked to abnormal signaling pathways is valid by generating gene expression profiles from 46 medulloblastoma samples. The investigators identified five medulloblastoma subgroups that differed from each other by their patterns of gene expression. These subgroups also differed according to their histologic (microscopic) characteristics and by how they behaved in patients.
For example, medulloblastomas in subgroup B occurred in patients who were older than 3 years and whose cancer was of the standard or classic type usually recognized under the microscope. In contrast, medulloblastomas in subgroup D occurred in children younger than 3 years, and these tumors had different characteristics from those in subgroup B.
The investigators showed that activation of different signal pathways contributes to the different medulloblastoma gene expression signatures found in each subtype. For example, the team found that genes in a pathway called WNT are especially active in tumors from subgroup B, while genes in the SHH pathway are e
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Contact: Bonnie Kourvelas
media@stjude.org
901-495-3306
St. Jude Children's Research Hospital
17-Apr-2006