Researchers based in the US have identified the molecules located on the surface of cancer cells, which allows for the identification and destruction of it by the immune system.
This research could result in new, more effective immunotherapies, which could be used in different cancer types.
According to Dr Sergio Quezada from Cancer Research UK, the researchers were searching for ‘signatures’ on the surface of the cancer cells which is linked to current immunotherapy responses. However, their findings have gone way beyond that. They discovered molecular motifs which will be used in the development of a new generation of treatments.
The research was led by a team from the Memorial Sloan Kettering Cancer Centre, New York. They undertook analysis of cancer DNA taken from 64 melanoma patients who had received treatment with a drug called ipilimumab. Half of the participants had responded to this drug.
The drug works by turning on the immune system of the body to attack the cancer, however it is only effective in a few patients. According to Dr Jedd Wolchok, this drug was found to be experimentally effective, but there was no information on the effect it had on patients.
After an analysis of the cancer DNA of the patients, the researchers looked for genetic mutations present in the cancer cells which could offer them a prediction of whether the patients had or had not responded to the drug. This allowed them to uncover a range of genetic mutations in some of the participants, which allowed the cancer cells to produce peptide antigens, protein molecules, which make the cancerous cells visible to the body’s immune response.
It seems that the mutations cause the antigens to copy small sections of proteins which are produced by viruses and bacteria, which explains their effectiveness at triggering the response from the immune system. The researchers state that more research is required to confirm this process.
Dr Quezada said that this research is huge news for immunotherapy researchers as this is the first time that scientists have been able to garner an idea of what is seen on a tumour by the immune system. He said this has been a hot topic of debate until now.
These findings could be used to decide which patients should receive ipilimumab.
Dr Timothy Chan, the leader of the research team, said that this is the first time that it has become feasible to develop a diagnostic test to aid in treatment decisions based on the prediction of who will respond.
Image Credit: NIAID