Medicine

DNA 'fingerprint' brings prospect of fast test for cancer

DNA 'fingerprint' brings prospect of fast test for cancer

Australian researchers at the University of Queensland have discovered a unique DNA structure that appears to be shared by many cancers and could be used to develop a simple diagnostic test that could be performed in under 10 minutes with the naked eye. In contrast, normal DNA folds in a somewhat different way, which does not result in such a strong affinity for gold, the researchers said.

"On normal cells, these [beads] are evenly distributed, but in cancer cells they're actually bunched up together", he said.

But on the genomes of cancer cells, methyl groups were positioned in intense clusters at specific locations.

Researchers at the University of Queensland have developed a simple test to see if there are DNA changes in the cells from blood and biopsy tissue.

The new method from the University of Queensland looks for differences in the genetic code of cancerous and healthy cells. In cancer cells, this patterning is hijacked so that only genes that help the cancer grow are switched on. Specifically, cancer DNA has clusters of methyl groups at specific locations and nearly no methylation elsewhere, while normal DNA's methyl groups are more evenly spread out across the entire genome.

Gold nanoparticles produced by laser ablation in heavy water. These 3D nanostructures could then be separated when they stick to solid surfaces, like gold.

Previous research has shown that the pattern of DNA methylation in cancer cells differs from that in healthy cells.

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The next step for the test will be validating it with tests on more cancer patients "to make sure that it actually stands up", followed by clinical trials that could take years, he said.

"We certainly don't know yet whether it's the Holy Grail for all cancer diagnostics, but it looks really interesting as an incredibly simple universal marker of cancer and as an accessible and cheap technology that doesn't require complicated lab-based equipment like DNA sequencing", Trau added.

The test can use "circulating free DNA", or DNA released into the blood from cancer or healthy cells. It's also unclear exactly how high the levels of cancer DNA need to be in order for the test to work, which would affect how early in the course of the disease the test could be used, the researchers said.

These instantly change color depending on whether the 3D nanostructures of cancer DNA are present.

So far they've tested the new technology on 200 samples across different types of human cancers, and healthy cells.

"This test could be done in combination with other simple tests, and become a powerful diagnostic tool that could not just say that you have cancer, but also the type and stage", said Carrascosa. He said, "We never thought this would be possible, because cancer is so complicated".

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'.