Quick dividing stem cells are a major source of cancer. A new study from researchers at Washington University School of Medicine in St. Louis have found that mature cells can revert back to acting like rapidly dividing stem cells. The work was published last week in Gastroenterology.
"As scientists, we have focused a good deal of attention on understanding the role of stem cells in the development of cancers, but there hasn't been a focus on mature cells," said senior investigator Jason C. Mills, M.D., Ph.D., a professor of medicine in the Division of Gastroenterology. "But it appears when mature cells return back into a rapidly dividing stem cell state, this creates problems that can lead to cancer."
Most cancer therapies target the rapidly dividing stem cells, but not the mature cells. "Cancer therapies target stem cells because they divide a lot, but if mature cells are being recruited to treat injuries, then those therapies won't touch the real problem," said first author Megan Radyk, a graduate student in Mills' laboratory. "If cancer recurs, it may be because the therapy didn't hit key mature cells that take on stem cell-like behavior. That can lead to the development of precancerous lesions and, potentially, cancer."
In this study, the researchers blocked the ability for a mouse's body to call on stem cells for help in the stomach. However, even without stem cells, the mice still developed a precancerous condition because mature stomach cells reverted back to a stem cell state to heal the injury.
Looking at human tissue specimens from people with stomach cancer, the researchers also found that the same mature cells in the stomach also reverted to a stem cell-like state and had begun to change and divide rapidly.
"Knowing these cells are leading to increased cancer risk may allow us to find drugs to keep mature cells from starting to divide and multiply," Mills said. "That may be important in preventing cancer not only in the stomach and GI tract but throughout the body."
Image: Graduate student Megan Radyk and Jason Mills, M.D., Ph.D., led a study revealing that although many cancer therapies target rapidly dividing stem cells, mature cells also seem to play a key role in initiating cancer, at least in forming precancerous lesions. Image courtesy of Matt Miller.