As well as removing the need for invasive procedures required by current tissue acquisition methods, this approach would be available to all brain cancer patients, even those whose tumours are currently considered inoperable, and would ultimately help clinicians determine the most effective treatment approach.
“In a liquid biopsy, we can find and analyse circulating tumour cells (CTCs) that have been shed by the original tumour. We can also find molecular fragments of the cancer, such as DNA, that will determine how the cancer may respond to certain treatments,” Associate Professor Becker says.
The research, which is currently at an early stage, is focused on glioblastoma (GBM), a type of brain tumour that more commonly appears in adults; and diffuse intrinsic pontine gliomas (DIPG), which are more likely to impact children.
As a first step, Becker and her team have established a world-first method for separating CTCs from billions of other cells in the blood. To do it, they use antibodies that recognise the molecules that are present on the surface of the cancer cell.
“Cancer cells are different from other cells,” Associate Professor Becker says.
“In particular, blood cells and cancer cells have different molecules on their surfaces. So, we can use particular antibodies that recognise molecules on the cancer cells.
“These antibodies are linked to small ion particles – what we call magnetic beads. Once we have those magnetic beads attached to the cancer cells – and they will only recognise the cancer cells – we can use magnetic force to separate them from billions of blood cells.”
By extracting these CTCs, the researchers can then look at them more closely to determine which genes are being expressed in the cells and look for mutations that predict response to specific treatment types.
The research team has also developed a series of analytical processes, called assays, to detect these mutations from tumour DNA found within the blood. To date, they have developed and validated three assays that can detect biomarkers for childhood DIPG and two for GBM – an important step towards a blood test to inform brain cancer treatment.
The research was funded by a seed grant from the Cancer Clinical Academic Group (CAG). Part of part of the Maridulu Budyari Gumal (SPHERE) academic health science partnership in Sydney, the CAG supports the development of collaborative cancer research across four key themes: cancer with poor outcomes, bringing ‘omics’ to clinical practice, reducing variation in clinical practice, and living better with and after cancer. As a brain cancer project, Associate Professor Becker’s research sits firmly within the cancers with poor outcomes theme.
As well as funding the development of novel research, the grant – a partnership between UNSW, the Ingham Institute, Western Sydney University, the South Western Sydney Local Health District and the Sydney Children’s Hospital Network – also fosters collaboration among researchers and clinicians.
“The funding allowed us to make progress with this project and more generally allowed us to start the communication and build collaborations with various clinicians who are seeing brain cancer patients,” Associate Professor Becker says.
“This seed grant puts us not only on the map in the context of this particular project, but it puts on the map as a team that does research in that area and collaborates with other clinicians and scientists with similar interests.”