Scientists’ potential cancer breakthrough
AN EXCITING new type of cancer treatment that could potentially stop tumours growing and spreading has been discovered by Queensland scientists.
The breakthrough by QIMR Berghofer researchers - in the field of immunotherapy - offers future hope for patients with cancers that do not respond to current immunotherapies.
Immunotherapy is a type of cancer treatment that helps the immune system fight cancer.
The team's research on mice is now to be replicated in humans.
QIMR Berghofer's Cancer Immunoregulation and Immunotherapy Laboratory Associate Professor Michele Teng said for the first time her team discovered many tumours displayed a particular molecule (MRI) on the cell surface which turned on an important regulatory MAIT cell that prevented the body's immune system from fighting the cancer.
"The cancer is effectively creating its own defence mechanism to evade immune attack and survive," she said.
The study findings have been published today in Cancer Discovery, a journal of the American Association for Cancer Research.
"While other regulatory cells of the immune system are known to stop T and NK cells from killing tumour cells, this is the first time it's been shown that these regulatory MAIT cells can do this job," the scientist said.
Associate Professor Teng said her team found that by giving mice an antibody that blocked MR1, this stopped the MAIT cells from becoming activated and the T and NK cells could respond, slowing cancer growth and stopping it spreading.
"This work demonstrates that antibodies that block MR1 could in future be an effective new immunotherapy," Associate Professor Teng said.
"It probably won't work on every cancer but it looks like it could be effective in treating cancers that can display the MR1 molecule.
"It also means this display of MR1 could be used to screen which patients would respond to this immunotherapy.
"We now need to replicate this research in humans."
Associate Professor Teng said while the research was at a very early stage and required more work, it was promising.
"The next step is to try to understand what kind of human tumours display MR1 as aprotective mechanism, which would then help us identify which tumours would respond bestto MR1-blocking immunotherapy," she said.
"Immunotherapies have been effectively used to treat more than 15 different cancer types butthe proportion of patients that respond for each cancer can differ."In patients with advanced melanoma for example, current approved immunotherapies workin about 50 per cent of cases, but half do not respond."