Nav: Home

A universal DNA nano-signature for cancer

December 04, 2018

Researchers from the University of Queensland's Australian Institute for Bioengineering and Nanotechnology (AIBN) have discovered a unique nano-scaled DNA signature that appears to be common to all cancers.

Based on this discovery, the team has developed a novel technology that enables cancer to be quickly and easily detected from any tissue type, e.g. blood or biopsy.

The study, which was supported by a grant from the National Breast Cancer Foundation and is published in the journal Nature Communications, reveals new insight about how epigenetic reprogramming in cancer regulates the physical and chemical properties of DNA and could lead to an entirely new approach to point-of-care diagnostics.

"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," explains AIBN researcher Dr Abu Sina.

To address this, Dr Sina and Dr Laura Carrascosa, who are working with Professor Matt Trau at AIBN, focussed on something called circulating free DNA.

Like healthy cells, cancer cells are always in the process of dying and renewing. When they die, they essentially explode and release their cargo, including DNA, which then circulates.

"There's been a big hunt to find whether there is some distinct DNA signature that is just in the cancer and not in the rest of the body," says Dr Carrascosa.

So they examined epigenetic patterns on the genomes of cancer cells and healthy cells. In other words, they looked for patterns of molecules, called methyl groups, which decorate the DNA. These methyl groups are important to cell function because they serve as signals that control which genes are turned on and off at any given time.

In healthy cells, these methyl groups are spread out across the genome. However, the AIBN team discovered that the genome of a cancer cell is essentially barren except for intense clusters of methyl groups at very specific locations.

This unique signature -- which they dubbed the cancer "methylscape", for methylation landscape -- appeared in every type of breast cancer they examined and appeared in other forms of cancer, too, including prostate cancer, colorectal cancer and lymphoma.

"Virtually every piece of cancerous DNA we examined had this highly predictable pattern," says Professor Trau.

He says that if you think of a cell as a hard-drive, then the new findings suggest that cancer needs certain genetic programmes or apps in order to run.

"It seems to be a general feature for all cancer," he says. "It's a startling discovery."

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

Taking advantage of this, the researchers designed an assay which uses gold nanoparticles that instantly change colour depending on whether or not these 3D nanostructures of cancer DNA are present.

"This happens in one drop of fluid," says Trau. "You can detect it by eye, it's as simple as that."

The technology has also been adapted for electrochemical systems, which allows inexpensive and portable detection that could eventually be performed using a mobile phone.

So far they've tested the new technology on 200 samples across different types of human cancers, and healthy cells. In some cases, the accuracy of cancer detection runs as high as 90%.

"It works for tissue derived genomic DNA and blood derived circulating free DNA," says Sina. "This new discovery could be a game-changer in the field of point of care cancer diagnostics." It's not perfect yet, but it's a promising start and will only get better with time, says the team.

"We certainly don't know yet whether it's the Holy Grail or not for all cancer diagnostics," says Trau, "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."
-end-


University of Queensland

Related Breast Cancer Articles:

Does MRI plus mammography improve detection of new breast cancer after breast conservation therapy?
A new article published by JAMA Oncology compares outcomes for combined mammography and MRI or ultrasonography screenings for new breast cancers in women who have previously undergone breast conservation surgery and radiotherapy for breast cancer initially diagnosed at 50 or younger.
Blood test offers improved breast cancer detection tool to reduce use of breast biopsy
A Clinical Breast Cancer study demonstrates Videssa Breast can inform better next steps after abnormal mammogram results and potentially reduce biopsies up to 67 percent.
Surgery to remove unaffected breast in early breast cancer increases
The proportion of women in the United States undergoing surgery for early-stage breast cancer who have preventive mastectomy to remove the unaffected breast increased significantly in recent years, particularly among younger women, and varied substantially across states.
Breast cancer patients with dense breast tissue more likely to develop contralateral disease
Breast cancer patients with dense breast tissue have almost a two-fold increased risk of developing disease in the contralateral breast, according to new research from The University of Texas MD Anderson Cancer.
Some early breast cancer patients benefit more from breast conservation than from mastectomy
Breast conserving therapy (BCT) is better than mastectomy for patients with some types of early breast cancer, according to results from the largest study to date, presented at ECC2017.
One-third of breast cancer patients not getting appropriate breast imaging follow-up exam
An annual mammogram is recommended after treatment for breast cancer, but nearly one-third of women diagnosed with breast cancer aren't receiving this follow-up exam, according to new findings presented at the 2016 Annual Clinical Congress of the American College of Surgeons.
Low breast density worsens prognosis in breast cancer
Even though dense breast tissue is a risk factor for breast cancer, very low mammographic breast density is associated with a worse prognosis in breast cancer patients.
Is breast conserving therapy or mastectomy better for early breast cancer?
Young women with early breast cancer face a difficult choice about whether to opt for a mastectomy or breast conserving therapy (BCT).
Breast density and outcomes of supplemental breast cancer screening
In a study appearing in the April 26 issue of JAMA, Elizabeth A.
Full dose radiotherapy to whole breast may not be needed in early breast cancer
Five years after breast-conserving surgery, radiotherapy focused around the tumor bed is as good at preventing recurrence as irradiating the whole breast, with fewer side effects, researchers from the UK have found in the large IMPORT LOW trial.

Related Breast Cancer Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".