PITTSBURGH, June 19 (UPI) -- U.S. cancer researchers have discovered cancer therapies often eliminate most of the disease but are thwarted by multiple-drug-resistant tumor cells.
University of Pittsburgh scientists said the resistant cells, called cancer stem cells, ultimately become the source of disease recurrence and eventual metastasis. But a team led by Assistant Professor Vera Donnenberg suggested effective chemotherapy must be able to target a small subset of cancer stem cells, which share the same protective mechanisms as normal lung stem cells.
The researchers identified a small, rare set of resting cancer stem cells in lung cancer samples that behave much like normal adult lung tissue stem cells. Both the cancer and normal stem cells were protected by multiple drug resistance transporters, even if the bulk of the tumor responded to chemotherapy.
"Because of the similarities between the way that normal stem cells and cancer stem cells protect themselves, cancer therapies have to be designed specifically to target cancer stem cells while sparing normal stem cells," Donnenberg said.
The research is available at www.regenerate-online.com/abstracts/1457.pdf
The study was presented last week in Toronto during a meeting of the Tissue Engineering and Regenerative Medicine International Society.
