FRIDAY, June 8, 2007 (HealthDay News) -- U.S. researchers have discovered that bone marrow stem cells attracted to an area of cancer growth frequently take on the outward appearance of the cancer cells around them.
But they say it's not clear that these stem cells actually help cancer develop.
Many scientists believe that the bone marrow stem cells do boost the growth and spread of cancer. But the University of Florida researchers say the stem cells may simply resemble the surrounding cancer cells, but not act like them.
The bone marrow stem cells "have the same kind of surface proteins" as cancer cells, noted study author Dr. Chris Cogle, an assistant professor of medicine at UF's College of Medicine Program in Stem Cell Biology and Regenerative Medicine.
But while the stem cells have the "same skin" as the surrounding cancer cells, the question is whether "they have the same guts," Cogle said.
"Our results indicate these cells act as developmental mimics; they come in and look like the surrounding neoplastic tissue, but they aren't actually the seed of cancer," Cogle said in a prepared statement.
"At the worst, these cells could help support cancerous tissue by providing it with growth factors or proteins that help the cancer grow and survive. At the very least, these marrow cells are just being tricked into coming into the cancerous environment and then made to walk and talk like they don't usually do," the researcher said.
The study will be published in the August issue of urnal Stem Cells.
Cogle noted that about five percent of cancerous tissue contains marrow-derived cells that resemble surrounding cancer cells. This "developmental mimicry" could affect the results of tests of new drugs on malignant tissue grown in the laboratory.
"If there are bone marrow cells in this cancerous tissue, these (bone marrow stem) cells may actually contaminate our cancer studies and could make a difference as to whether or not investigational drugs we're testing work or don't work," Cogle said.
"The significance of this is new treatments may work in the culture dish but may not translate to the clinic or the hospital room, and for many reasons. One of the reasons could be bone marrow contamination," the expert said.
The U.S. National Cancer Institute has more about cancer.