That normal cells become cancerous when they are treated with inorganic arsenic has been previously determined by this same group of researchers. Their new research shows that when these cancer cells are placed close to -- but not in contact with -- normal stem cells, the normal stem cells very rapidly acquire the characteristics of cancer stem cells, demonstrating that malignant cells are able to send molecular signals through a semi-permeable membrane, where cells can't normally pass, and turn the normal stem cells into cancer stem cells.
"This paper shows a different and unique way that cancers can expand by recruiting nearby normal stem cells and creating an overabundance of cancer stem cells," said Michael Waalkes, Ph.D., Group Leader at the National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, part of NIH.
This may help explain observances by researchers working with arsenic that arsenic often causes multiple tumors of many types to form on the skin or inside the body.
Inorganic arsenic affects the drinking water of millions of people worldwide. A growing body of evidence suggests that cancer is a stem-cell based disease. Normal stem cells are essential to normal tissue regeneration, and to the stability of organisms and processes. But cancer stem cells are thought to be the driving force for the formation, growth, and spread of tumors.
"Using stem cells to answer questions about disease is an important new growing area of research. Stem cells help to explain a lot about carcinogenesis, and it is highly likely that stem cells are contributing factors to other chronic diseases," added Waalkes.
Adapted from the NIH/National Institute of Environmental Health Sciences announcement.