Scientists at QIMR Berghofer Medical Research Institute have found that an antibody slows common cancers from metastasising, or growing and spreading.
During laboratory tests the antibody inhibited the spread of melanoma, lung, breast and prostate cancer cells by activating immune cells known as Natural Killer (NK) cells.
The ground-breaking discovery paves the way for a new direction in the field of cancer treatment.
The study was led by Professor Mark Smyth, who is the head of QIMR Berghofer’s Immunology Department, and has been published in the journal Cancer Discovery.
Professor Smyth and his colleagues have previously discovered that a protein on the surface of NK cells, known as CD96, helps to camouflage cancer cells by preventing the NK cells from responding to cues from cancer cells (see previous media release).
“The protein CD96 sits on the surface of these immune cells and its role is to stop the immune cells from becoming over-activated and attacking the body’s own healthy cells,” Professor Smyth said.
“We’ve previously found that cancers hijack this process and stop the immune system from recognising cancer cells and becoming activated. This allows the cancer to spread through the body.”
In the latest finding, Professor Smyth and his colleagues have shown that an antibody can be used to block CD96, enabling more effective NK cell activation, thereby allowing the NK cells to detect and destroy the cancer cells.
The finding paves the way for a new avenue in immunotherapy treatments to fight cancer. Immunotherapy is a fast-developing field that is revolutionising the treatment of cancer. It involves using a patient’s own immune system to treat cancer and other serious diseases.
“This is a very significant and exciting finding,” Professor Smyth said.
“Immunotherapy treatments are already proving highly successful in treating some cancers. But to date most of the focus has been on developing new treatments that work on a different kind of immune cell known as a cytotoxic T cell.
“By contrast, we have shown that we can slow the spread of cancer by targeting Natural Killer cells. We think that in future this method will be just as important and effective as other immunotherapy treatments that are already in use.”
Significantly, the study found that the antibody was even more effective in slowing the spread of the cancer cells and prolonging survival when used in combination with existing agents that target and activate cytotoxic T cells.
“We think that in future a human version of this antibody will be used in combination with existing immunotherapy treatments,” Professor Smyth said.
“We hope that by activating both the NK and cytotoxic T cells, we may be able to stop the spread of cancers before they become aggressively metastatic.”
The study was funded by the National Health and Medical Research Council (NHMRC), Cancer Council Queensland, the Cancer Research Institute and QIMR Berghofer.
It involved collaborators from the Washington University School of Medicine, Juntendo University in Tokyo and the Hannover Medical School.