Researchers have devised a test that can quickly and cheaply identify any type of cancer from any type of tissue, be that blood or a biopsy sample. Indeed, this test is so convenient and affordable that in the not-too-distant future we could all be carrying around our own personal cancer detector – on our cell phones.
The test hinges on a unique DNA signature that appears to be found in all cancers, discovered by a team of scientists at the University of Queensland's Australian Institute for Bioengineering and Nanotechnology (AIBN). Their findings are published in the journal Nature Communications.
"Because cancer is an extremely complicated and variable disease, it has been difficult to find a simple signature common to all cancers, yet distinct from healthy cells," Abu Sina, a researcher at the Institute, said in a statement.
And so, Sina and colleagues compared the epigenetic patterns on the genomes of cancer cells to those of healthy cells, specifically focusing on patterns of methyl groups. These work a little bit like a remote control device, turning various genes on and off.
The team noticed that in cancer cells, methyl groups were clustered at certain positions on the genome – a stark contrast to healthy cells where the groups are dispersed throughout. This "unique" signature was studied in all types of breast cancer looked at as well as various other types of cancer, including bowel, prostate, and lymphoma cancers. Matt Trau, a professor at AIBN who led the research, describes it as like a genetic program or app that the cancerous cell needs in order to function.
"Virtually every piece of cancerous DNA we examined had this highly predictable pattern," he explained.
But that's not all. These signatures are gold-hungry, which makes them possible to identify with a simple color-change test. Trials are still in the initial stages and it has only been tested on breast, bowel, prostate, and lymphoma cancers but the researchers say it could have the ability to spot any type of cancer with up to 90 percent accuracy.
So, how does it work?
First, it relies on a phenomenon called circulating free DNA, which circulates the body after it is emitted from the cancer. These DNA fragments contain cancer's unique signature but can be picked up in a blood sample or biopsy, making it possible to identify cancer in a test even if its source is unknown.
The actual test uses a water-based solution containing gold nanoparticles, which turn the liquid a reddish color. When cancerous cells are added, the methyl groups cause the DNA fragments to fold up into 3D structures. These are attracted to the gold nanoparticles and the solution remains the reddish color. In contrast, when healthy cells are added, the DNA and gold nanoparticles interact differently and the solution turns blue.
While the test might not be able to tell you exactly where the cancer is located, a positive result could spur further testing to identify the source. Plus it is cheap and quick, offering up a result in under 10 minutes.
What's more, the researchers say this type of technology has been adapted for electrochemical systems, which could pave the way for portable detection that could one day be carried out on a cell phone near you.
"We certainly don't know yet whether it's the Holy Grail or not for all cancer diagnostics,” Trau continued, "but it looks really interesting as an incredibly simple universal marker of cancer, and as a very accessible and inexpensive technology that does not require complicated lab-based equipment like DNA sequencing."