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.
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.
One question that researchers have been trying hard to answer is: How do we turn cold tumors into hot tumors that will respond to immunotherapy?
A team of investigators from the Rush University Medical Center in Chicago, IL, may now have found an effective way of doing just that by using inactivated flu viruses — essentially, flu vaccines — in mouse model experiments.
The researchers explain their process, as well as their findings, in a study paper that now features in the journal PNAS.
New approach shrinks tumors in mice
The 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.
“However,” he adds, “there are many factors we do not understand about live infections, and this effect does not repeat in tumors where influenza infections do not naturally occur, like skin.”
So, the researchers injected an inactivated influenza virus into melanoma tumors in mouse models.