Stanford researchers tried a new approach in fighting cancerous tumours using a vaccine in mice, and they found that the vaccine not only eliminated the tumours they targeted, but it also eliminated the cancer found in the mice.
Stanford Medicine reported that the researchers used a one-time application of two agents, which eliminated tumours from all over the body.
''This approach bypasses the need to identify tumour-specific immune targets and doesn't require wholesale activation of the immune system or customization of a patient's immune cells,'' said Ronald Levy, MD, professor of oncology.
According to Stanford Medicine, one agent is currently already approved for use in humans, while the other half has been tested for human use in several unrelated clinical trials.
''The approach worked startlingly well in laboratory mice with transplanted mouse lymphoma tumors in two sites on their bodies. Injecting one tumor site with the two agents caused the regression not just of the treated tumor, but also of the second, untreated tumor. In this way, 87 of 90 mice were cured of the cancer. Although the cancer recurred in three of the mice, the tumors again regressed after a second treatment,'' according to Stanford Medicine press release.
The promising results reported by Levy provide further hope that immunotherapy is the future of cancer treatment, according to commentators.
Rather than bombarding the body with high doses of toxic chemicals and radiation, our own immune systems can be recruited to fight back.
In the two-step cancer vaccine, used by Levy, a short stretch of DNA called a CpG oligonucleotide was first injected into the tumour site. CpG is something, a Toll-like receptor, is a special kind of immune system protein that recognises invading pathogens.
When miniscule amounts of the protein (millionths of a gram) were injected into the mouse tumours, they activated the expression of a receptor called OX40 on nearby T cells that had arrived at the tumour site, but had been rendered inactive.
The second injection contained an antibody that attached to those newly activated OX40 receptors and essentially reactivated the T-cells. Before the suppression of their activity the same T cells were primed to respond to the precise antigens produced by the tumour. With the boost from the vaccine, they were now back in action.