A new study has revealed a group of colon cancer cells that can either suppress or promote tumor growth. Researchers stated that these "two-faced" cells are a subset of T-regulatory (Treg) cells that are known to suppress immune response.
The study, published in the journal Science Translational Medicine, also showed that the two-faced cells were differentiated in their cancer growth or suppression forms by the presence of a protein called RORγt.
"The subset of Tregs that expand in human colon cancer is different from the Tregs that abound in healthy individuals in their ability to suppress inflammation," said Khashayarsha Khazaie team leader of the research and an associate professor at the Robert H. Lurie Comprehensive Cancer Center at Northwestern University. "Since their discovery, Tregs have been assumed to be harmful in cancer based on the knowledge that they suppress immunity. More recent clinical studies have challenged this notion. Our work shows that Tregs, by suppressing inflammation, are normally very protective in cancer; it is rather their switch to the expression of RORγt that is detrimental."
The study identified the abnormal Treg subset in mice with hereditary colon cancer, then looked for the same cells in human colon cancer patients. Research has already demonstrated that transferring Tregs from healthy mice to cancerous mice protects the cancerous mice from colitis and colitis-induced cancer. By inhibiting RORγt in Tregs, Khazaie and his team were able to protect mice against hereditary colon cancer.
"Tregs are actually very useful in the fight against cancer," said Khazaie. "We can do better by targeting RORγt or other molecules that are responsible for the expansion of this Treg subset, instead of indiscriminately eliminating all Tregs. We are very excited about the therapeutic options that targeting specific subsets of Tregs could provide in human solid tumor cancers, and that is our next immediate goal."