Researchers in Europe have made an interesting discovery that expands the knowledge of how proteins in humans reduce the efficacy of cancer treatments.
In this study, researchers show for the first time how T cells speed up the secretion in human cancer cells of a protein that enables cancer cells to evade the immune response.
This discovery could help in the effective treatment of some cancers that are currently incurable.
The study, published in the Journal for ImmunoTherapy for Cancer, was carried out by researchers from the Medway School of Pharmacy (MSOP), which is a collaboration between the University of Kent and the University of Greenwich. Counterparts from Switzerland’s University Hospital Bern (Inselspital) and Germany’s University of Oldenburg were also involved.
The role of galectin-9
In trying to grasp why cancer treatments don’t work in some cases, scientists have honed in on galectin-9. This protein is present in all mammals and is believed to regulate immune responses in humans.
There is a seemingly increasing focus on galectin-9 among researchers looking to develop or improve cancer treatments. This is because, when secreted, it blocks or suppresses the anti-cancer immune response and so enables the disease to worsen.
Galectin-9 expressly blocks the cancer-fighting activities of T cells, a form of white blood cells that should help remove tumors. The protein kills cytotoxic T lymphocytes and impairs natural killer (NK) cell activity.
Because of this observed role, researchers believe that being able to block galectin-9 could make it possible to cure more cancers. This would enable T cells to be more potent against cancer cells and make treatments more effective.
Researchers had previously observed a high expression of this immune-suppressing protein in many human cancers. These included glioblastomas (a deadly cancer of the brain or spinal cord) and other very aggressive types of tumors. The five-year survival rate for glioblastomas is lower than 10 percent, as per researchers.
Treatment of incurable cancer
The research team wanted to find out in this study whether T cells can promote the secretion of galectin-9 in human cancer cells obtained from solid malignant tumors. It was also interested in finding out if the soluble form fuels greater immunosuppression, compared to proteins on the cell surface.
The common belief was that, at rest, solid tumor cells secrete little or no galectin-9.
For the first time, researchers found in this study that T cells induce the secretion of this immune suppression protein. This was observed in diverse types of cancer cells derived from solid tumors in humans through differential biochemical mechanisms.
“These results not only confirm what we already knew about this cancer-treatment-fighting protein but also help us better understand its functions and how it works with other types of tumors,” said Dr. Vadim Sumbayev, MSOP Director of Research and leader of the research team.
These findings point out the need for further research into galectin-9 as well as its regulatory pathways.
“Understanding Galectin-9 and the whole anti-cancer immune evasion machinery would allow us to map these pathways and rapidly identify them in each individual patient by using simple biochemical marker tests and make existing, or new treatments, more effective,” said Dr. Sumbayev.
The researchers noted that this knowledge could help to personalize treatments for cancer patients, thereby enhancing efficacy. It could make more cancers become curable. This would expectedly also improve patients’ survival rate as well as their quality of life.
A deep knowledge of galectin-9 and its machinery for evading immune response would not only enhance treatment efficacy but may also make for affordable therapy.