CBNS Researchers based at UNSW Sydney have found a way to detect a very low amount of a cancer biomarker in undiluted blood in just 15 minutes, a result that could eventually play a key role in evaluating the effectiveness of cancer treatments.
The researchers are hoping the technology to detect the PD-L1 biomarker in a blood sample will be available in the next five years. PD-L1 – or programmed death-ligand 1 – is a protein that is known to help tumour cells evade the immune system by preventing the activation of T-cells which are used to destroy cancer. It is a predictive biomarker for several types of cancers such as melanoma skin cancer, colorectal and bladder cancer as well as non-small-cell lung cancer.
PD-L1 levels are currently found using immunohistochemistry tests from a biopsy, or by using a scan or imaging techniques. Now the CBNS researchers, have released nanoparticles in blood samples to detect very low amounts of PD-L1 in undiluted whole blood for the first time.
“The nanoparticles are, in effect, dispersible electrodes,” first author and CBNS PhD student under the supervision of CI Professor Justin Gooding, Parisa Moazzam says. “When they are circulated through the matrices of undiluted whole blood, they capture PD-L1, a cancer biomarker, before a magnet is used to re-collect the nanoparticles with newly attached PD-L1.”
Ms Moazzam says the levels of PD-L1 in patients with cancer can show a strong correlation with the predicted response to immunotherapy and assessment of cancer treatment outcomes.
“A PD-L1 expression measurement in the blood means researchers can potentially identify patients who might respond well to immunotherapy treatment and evaluate treatment responses,” she says.
Ms Moazzam says while immunotherapy is showing excellent therapeutic results in multiple cancers for some patients, it is expensive. Current tests for PD-L1 only result in relative amounts of the biomarker, but she says this latest research can give absolute amounts, which greatly increases sensitivity and test accuracy.
“This is the first electrochemical detection process which has the potential to improve conventional tests with an early, sensitive and accurate diagnosis; to reduce treatment costs; and improve outcomes and patient survival rate,” she says.
Read the study in Chemical Communications.
17 MAY 2021, original news piece written by Dianne Nazaroff from UNSW.