Experts have theorized that stubborn and apparently undetectable stem cells are left unscathed by existing treatments, linger in the body and eventually reform the tumor or cause the cancer to spread.
"They go into remission then we don't detect the disease at all for one, two, three years, and then it comes back," explained study senior author Dr. Timothy Cripe, professor of pediatrics at Cincinnati Children's Hospital Medical Center and the University of Cincinnati. "Stem cells would explain that. We need to understand those cells and target them."
"If cancers are being seeded by a few cells, they need to be the target. We have maxed-out therapy for cancers, in particular neuroblastoma. We need to identify something novel and different," he continued.
These researchers identified and then grew several lines of human neuroblastoma cells that seemed to have characteristics of neural stem cells -- meaning, among other things, that they could grow into different types of cells including tumors. The cells also carried the protein nestin, which is a marker for nerve stem cells and is also present in neuroblastoma cells.
When the stem cells were infected with a herpes simplex virus which specifically targets nestin, they did not form tumors over the next 60-day period. When infected with a different virus that does not target nestin, mice developed tumors within 40 days. Mice who were uninfected with either virus developed tumors within 30 days.
But, Cripe cautioned, "we used cell lines propagated in plastic dishes. [We need to know] how does that relate to cells in humans?"
There's more on neuroblastomas at the U.S. National Cancer Institute.
SOURCES: Timothy Cripe, M.D., professor, pediatrics, Cincinnati Children's Hospital
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