Finding Shows Arsenic Can Cause Cancer
Arsenic has long been known as a human carcinogen. Now, researchers are calling the inorganic material a cancer-causing element.
Scientists at the National Institutes of Health’s (NIH) National Toxicology Lab have evidence that exposure to arsenic can turn normal stem cells into cancer stem cells and spur tumor development. Dr. Michael Waalkes, who led the laboratory team in the research and development of a paper that appears online in Environmental Health Perspectives, says that normal cells become cancerous when they are treated with inorganic arsenic. When these cancer cells are placed near, but not in contact with normal stem cells, the stem cells quickly acquire the characteristics of cancer stem cells.
“This paper shows a different and unique way that cancers can expand by recruiting nearby normal stem cells and creating overabundance of cancer stem cells,” says Waalkes. “The recruitment of normal stem cells into cancer stem cells could have broad implications for the carcinogenic process in general, including tumor growth and metastases.”
Waalkes points out that normal stem cells are essential to normal tissue regeneration and to the stability of organisms and processes. Cancer stem cells are thought to be the driving force for the formation, growth, and spread of tumors. 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.
Stem cells have long been controversial in regards to research and claims that they increase abortions, but the cells are unique in the human body providing an excellent platform to study cell growth. Stem cells tend to hang around for years and are capable of dividing and renewing themselves. Dr. Linda Birnbaum, director of the National Institute of Environmental Health Sciences says the cells may be a key to understanding diseases in adults.
“Most cancers take 30 to 40 years to develop,” said Birnbaum says. “It makes sense that stem cells may play a role in the developmental basis of adult disease. We know that exposure to toxicants during development and growth can lead to diseases later in life.”
Waalkes and his team are only beginning their look at the importance of stem cell development and cancers. The laboratory team will now research whether this finding is unique to arsenic or if it is applicable to other organic and inorganic cancinogens.