One of the fascinating things about stem cell research is how quickly the field is evolving. It seems like every other day a new study is published that highlights a new discovery that makes us stop and think how this new knowledge affects our understanding of stem cells and the diseases we are trying to treat.
The latest example came this week with research from Canada identifying a new kind of stem cell population found in the colon that can lead to cancer growth.
The study, published in the journal Cell Stem Cell, is important because colon cancer is the third most commonly diagnosed cancer and the second leading cause of cancer death in both men and women, claiming around 50,000 lives in the U.S. alone every year.
Stem cells are essential for helping replace the lining of our colon and intestine every three or four days. In the intestine there are two kinds of stem cells, a rapidly recycling one called Lgr5+ and a slower one. However, scientists had only been able to identify Lgr5+ stem cells in the colon. Because this stem cell type is sensitive to radiation physicians believed that radiation therapy would be effective against colon cancer.
Now, researchers at Lawson Health Research Institute in Ontario, Canada, have identified another stem cell in the colon, one that is both long-lived and radiation resistant.
They also found that this new stem cell population can not only give rise to tumors in the colon, it can also help sustain and support the growth of the cancer.
In a news release Dr. Samuel Asfaha, a clinician-scientist at Lawson and the lead author of the study, says this new piece of information gives them vital new information in fighting the cancer:
“The identification of more than one stem cell pool in the colon has proven challenging. These findings are exciting, as we have identified an important new target for cancer therapy. It is also proof that more than one stem cell can give rise to and sustain tumors, telling us that our cancer therapy needs to target more than one stem cell pool.”
Asfaha says knowing that there is a pool of stem cells that don’t respond to radiation means researchers must now look for new, more effective ways of tackling them, so we are better able to help patients with colon cancer.
CIRM is funding a number of therapies that target solid tumor cancers, the kind that includes colon cancer. One, run by Dr. Dennis Slamon of University College, Los Angeles, is now in clinical trials. You can read about that work here.