Published: Wed, December 05, 2018
Medicine | By Brett Sutton

Nano-signature discovery could revolutionise cancer diagnosis

Nano-signature discovery could revolutionise cancer diagnosis

It is hoped that the new test will eventually be performed at the same time as routine blood tests, such as a cholesterol check - or even using a mobile phone app.

Researchers have discovered a curious difference between the DNA from cancer cells and that from healthy cells, and this finding could lead to a new blood test for cancer.

The researchers have dubbed it the cancer "methylscape" - for methylation landscape.

Joyce Ohm, an associate professor of oncology at Roswell Park Comprehensive Cancer Center in Buffalo, New York, agreed that the work is "an exciting potential advance" in looking for a general epigenetic biomarker for cancer. Trau said, "Virtually every piece of cancerous DNA we examined had this highly predictable pattern..."

Abu Sina, Research Fellow, The University of Queensland; Laura G. Carrascosa, Postdoctoral Research Fellow, The University of Queensland, and Matt Trau, Professor, The University of Queensland.

Healthy cells ensure they function properly by patterning their DNA with molecules called methyl groups. The test however can detect only the presence of the cancer and not the site of the cancer, stage of the cancer or the type of the cancer.

"Our technique could be a screening tool to inform clinicians that a patient may have a cancer, but they would require subsequent tests with other techniques to identify the cancer type and stage", Carrascosa said.

Cancer blood tests became possible after scientists realised the importance of DNA released when cancer cells die, which is carried in the bloodstream. These modifications do not change the DNA sequence, but instead affect how cells "read" genes.

Dr Ged Brady, from the Cancer Research UK Manchester Institute, said: 'Further clinical studies are required to evaluate the full clinic potential of the method'.

It spots tiny amounts of DNA floating through vessels that could only have come from tumors and not from healthy cells.

When placed in solution, those intense clusters of methyl groups also caused cancer DNA fragments to fold up into three-dimensional nanostructures that really like to stick to gold.

The DNA in cancer cells can be riddled with mutations that drive the growth of a specific tumour, but these mutations tend to differ depending on the type of cancer.

"That absolutely stunned us", Professor Trau said.

"This led to the creation of low-cost and portable detection devices that could eventually be used as a diagnostic tool, possibly with a mobile phone", said Professor Matt Trau, one of the lead researchers on the project.

Trials were conducted on 200 samples including breast, lymphoma, prostate and colorectal, and the results had 90 percent accuracy of detecting cancer.

Sina said: "It works for tissue-derived genomic DNA and blood-derived circulating free DNA".

Although not yet ideal, the researchers said it is a promising start and will only get better with time.

"If it's very sensitive, we could use it for early diagnosis of cancer ... especially for cancers where there is no screening paradigm, like ovarian and pancreatic", she said.

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