Northwestern Medicine researchers have discovered a "two-faced" group of cells at work in human colon cancer, with opposing functions that can suppress or promote tumor growth. These cells are a subset of T-regulatory (Treg) cells, known to suppress immune responses in healthy individuals
In this previously unknown Treg subset, the presence of the protein RORãt has been shown to differentiate between cancer-protecting and cancer-promoting properties.
The Northwestern team, led by Khashayarsha Khazaie, research associate professor at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, recently reported their findings in the journal Science Translational Medicine.
"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 Khazaie. "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 RORãt that is detrimental."
The Northwestern team's work builds on observations, which demonstrated that the transfer of Tregs from healthy mice to mice with colitis or colitis-induced cancer actually protected the mice from colitis and colitis-induced cancer.
After identifying the abnormal Treg subset in mice with hereditary colon cancer, Khazaie and lead author Nichole Blatner, research assistant professor at Lurie Cancer Center, worked with Mary Mulcahy, MD, associate professor of hematology and oncology, radiology, and organ transplantation, and David Bentrem, MD, Harold L. and Margaret N. Method Research Professor in Surgery, of Northwestern University Feinberg School of Medicine, to look for the same cells in colon cancer patients.
"To our delight, we found the same Treg alterations in cancer patients," said Khazaie.
Of cancers affecting both men and women, colorectal cancer (cancer of the colon and rectum) is the second leading cancer killer in the United States. In 2012, approximately 140,000 Americans were diagnosed with colon or rectal cancer, while more than 50,000 deaths occurred from either cancer, according to the Centers for Disease Control.
"The significance of our discovery became apparent when by inhibiting RORgt in Tregs we were able to protect mice against hereditary colon cancer," Khazaie said.
He notes that several ongoing clinical trials exist based on targeted elimination of all Tregs in cancer patients. However, the discovery of Treg diversity in cancer, and its central role in control of cancer inflammation, may lead to new approaches for therapeutics.
"Tregs are actually very useful in the fight against cancer," he says. "We can do better by targeting RORãt 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."
Khazaie's team is moving forward with plans to test novel drugs that inhibit RORãt.
This research was made possible by philanthropic support through the Lurie Cancer Center and Steven Rosen, MD, director of the Lurie Cancer Center and the Genevieve E. Teuton Professor of Medicine at the Feinberg School.
In addition to Northwestern University researchers, Khazaie and Blatner collaborated with Fotini Gounari, University of Chicago, and Christophe Benoist, Harvard Medical School, on this discovery.
Marla Paul | EurekAlert!
Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University
Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences