The idea of a cancer vaccine is something researchers have been working on for over 50 years, but until recently they were never able to prove exactly how such a vaccine would work.
In a recent study, researchers at Université de Montréal has demonstrated that a vaccine can work.
Not only that, it could become an extremely effective, non-invasive and cost-effective cancer-fighting tool.
The discovery represents a major breakthrough in the quest for a cancer vaccine, a highly competitive pursuit in which numerous research teams around the world are engaged.
Unlike other teams, this team looked for a solution in an unusual place: non-coding DNA sequences.
In 2000 and 2005, a number of studies were able to show that immune-defence cells (T lymphocytes) are capable of recognizing and penetrating cancer cells in order to attack them.
T lymphocytes recognize tumors by the presence of foreign antigens – or peptides – on the surface of cells.
However, even if these antigens are recognized by the immune system, they do not sufficiently stimulate it for the lymphocytes to target and destroy them.
As such, the search for a vaccine has focused on identifying tumor-specific antigens in order to allow the immune system to attack them more effectively.
Since these antigens are the result of defective genes, various research teams have tracked the culprits to the portion of DNA known to encode antigens and proteins.
But they have not been successful.
Using mice injected with various types of cancer cells, the team was able to identify numerous antigens deriving from the non-coding portion of DNA, several of which were both specific to cancer cells and common to different types of cancer.
This allowed the team to develop a vaccine based on leukemia cells containing some of the identified antigens, which was administered to the mice.
The results were highly encouraging.
The same antigens were subsequently identified in leukemia cells in humans.
The team’s findings are extremely promising and opening up the possibility for the development of vaccines to treat leukemia and lung cancer in humans.
The team focused on these two specific types of cancer because they are at opposite ends of the spectrum in terms of the number of mutations at their source.
The fact that the vaccine has proven effective to treat leukemia, which is caused by a small number of mutations, holds promise for the efficacy of this therapy in fighting all other types of cancer as well.
At the same time, one of the obstacles in developing a vaccine for humans is that our genetic diversity is much greater than that of mice.
The team believes that clinical trials with humans could start within the next two to three years.
Developing therapeutic cancer vaccines targeting the antigens identified by the team would be a cost-effective way to save lives, while at the same time greatly simplifying treatment of this terrible disease, notably by limiting the many side effects of chemotherapy.
The study is published in Science Translational Medicine.
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Source: Science Translational Medicine
