DALLAS Sept. 1, 2006 Mature muscle fibers, rather than their less-developed neighbors, are the tissues that turn malignant in a soft-tissue cancer that strikes children and teens, researchers at UT Southwestern Medical Center and Children's Medical Center Dallas have found.
The research, performed in fruit flies, not only provides a clue to how the cancer arises, but also means that scientists can use the flies to search for other genes involved in the cancer.
"Never before has any animal model system shown that new cells can be generated from differentiated skeletal muscle," said Dr. Rene Galindo, lead author of the study, assistant professor of pathology at UT Southwestern and a pediatric pathologist at Children's.
"Skeletal muscle had been viewed as being biologically fixed," he said.
The research is available online and is being published in the Sept. 5 issue of the Proceedings of the National Academy of Sciences.
The researchers focused on alveolar rhabdomyosarcoma, a subtype of rhabdomyosarcoma, the sixth most common childhood cancer. Alveolar rhabdomyosarcoma is an aggressive, often fatal form of cancer that occurs primarily in the trunk, arms and legs of older children or teenagers.
The disease starts when one of two genes, called PAX3 and PAX7, fuses with another gene called FKHR, or "Forkhead."
Scientists, however, had not known which type of tissue turned into tumor cells: mature muscle cells or the more immature cells that surround or form them. The question arose partly because of the number of nuclei found in each cell.
The tumor cells each have a single nucleus, while developed muscle tissue contains many nuclei up to several hundred. The muscle cells are surrounded by satellite cells, which can develop into mature muscle cells, each having a single nucleus. Both muscle and satellite cells are in turn surrounded by adult stem cell-like cells.
The researchers used la
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Contact: Aline McKenzie
aline.mckenzie@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
1-Sep-2006