Islamabad (Pakistan Point News / Online - 12th January, 2020) Recent experiments in mouse models have shown that injecting an inactivated flu virus into cancer tumors makes them shrink and boosts the effectiveness of immunotherapy.Is the flu shot the next step in fighting cancer?When it comes to cancer tumors, many factors influence whether or not they will respond to treatment. One of these is whether the tumors are "hot" or "cold." What does this mean?In recent years, a new type of anticancer therapy has been gaining in popularity: immunotherapy.
This form of therapy works by boosting the body's own immune response to cancer tumors.However, for the therapy to have a higher chance of working, the tumors have to be "hot" tumors that is, they must contain immune cells. If a tumor does not contain (enough) immune cells, or contains immunosuppressant cells, it is called a "cold" tumor.New approach shrinks tumors in miceThe researchers got the idea for their new study by looking at data from the National Cancer Institute.
The data indicated that people with lung cancer who had also been in the hospital with influenza-related lung infections tended to live longer than those with lung cancer who had not had a flu virus.When they recreated this scenario in mouse models, the researchers confirmed that those with cancer tumors and influenza-related infections tended to live longer.Going forward, the team wants "to understand how our strong immune responses against pathogens like influenza and their components could improve our much weaker immune response against some tumors," says senior study author Dr.
Andrew Zloza.They found that this "vaccine" turned tumors from cold to hot by increasing the concentration of dendritic cells in the tumors. These cells can stimulate an immune response, and indeed, they led to an increase in CD8+ T cells. These can recognize and destroy cancer cells.As a result, the mice's melanoma tumors either grew at a slower rate or started shrinking.Flu shots might boost immunotherapy"Our successes with a flu vaccine that we created made us wonder if seasonal flu vaccines that are already [Food and Drug Administration]-approved could be repurposed as treatments for cancer," Dr.
Zloza adds."Since these have been used in millions of people and have already been shown to be safe, we thought using flu shots to treat cancer could be brought to patients quickly."The researchers therefore worked with specially engineered mouse models, into which they were able to transplant both tumors and immune cells from humans with lung cancer and metastatic melanoma.Dr. Zloza and colleagues found that injecting these human-derived tumors with a regular, FDA-approved flu shot led them to shrink.
"Such [a] transplant allows us to utilize patient-grade drugs in a living system. This is as close as we can get to testing something ahead of a clinical trial," he explains.The researchers also wanted to see if they could use flu shots as an adjuvant therapy that is, as an aid to existing anticancer therapies.So, in additional experiments, they delivered the flu shots alongside a form of immunotherapy that relies on immune checkpoint inhibitors. These are drugs that stimulate immune cells to mount an attack against cancer tumors.
