This research could lead to a useful liquid biopsy test that would be a powerful new tool for clinical laboratories and anatomic pathologists
Cancer researchers have long sought the Holy Grail of
diagnostics—a single biomarker that can quickly detect cancer from blood or
biopsied tissue. Now, researchers in Australia may have found that treasure. And
the preliminary diagnostic test they have developed reportedly can return
results in just 10 minutes with 90% accuracy.
In a news release, University of Queensland researchers discussed identifying a “simple signature” that was common to all forms of cancer, but which would stand out among healthy cells. This development will be of interest to both surgical pathologists and clinical laboratory managers. Many researchers looking for cancer markers in blood are using the term “liquid biopsies” to describe assays they hope to develop which would be less invasive than a tissue biopsy.
“This unique nano-scaled DNA signature appeared in every type of breast cancer we examined, and in other forms of cancer including prostate, colorectal, and lymphoma,” said Abu Sina, PhD, Postdoctoral Research Fellow at the Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland (UQ), in the news release.
“We designed a simple test using gold nanoparticles that
instantly change color to determine if the three-dimensional nanostructures of cancer
DNA are present,’ said Matt
Trau, PhD, Professor of Chemistry at the University of Queensland, and
Deputy Director and Co-Founder of UQ’s AIBN, in the news release.
The team’s test is preliminary, and more research is needed before
it will be ready for Australia’s histopathology laboratories (anatomic
pathology labs in the US). Still, UQ’s research is the latest example of how
increased knowledge of DNA is making it possible for researchers to identify
new biomarkers for cancer and other diseases.
“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 inexpensive technology
that doesn’t require complicated lab-based equipment like DNA sequencing,” Trau
added.
The UQ researchers published their study in the journal Nature Communications. In it, they noted that “Epigenetic reprogramming in cancer genomes creates a distinct methylation landscape encompassing clustered methylation at regulatory regions separated by large intergenic tracks of hypomethylated regions. This methylation landscape that we referred to as ‘Methylscape’ is displayed by most cancer types, thus may serve as a universal cancer biomarker.”
While methyl patterning is not new, the UQ researchers say they were the first to note the effects of methyl pattern in a particular solution—water. With the aid of transmission electron microscopy, the scientists saw DNA fragments in three-dimensional structures in the water. But they did not observe the signature in normal tissues in water.
“To date, most research has focused on the biological consequences of DNA Methylscape changes, whereas its impact on DNA physicochemical properties remains unexplored,” UQ scientists Matt Trau, PhD (left), Abu Sina, PhD (center), and Laura Carrascosa (right), wrote in their study. “We exploit these Methylscape differences to develop simple, highly sensitive, and selective electrochemical or colorimetric one-step assays for the detection of cancer.” (Photo copyright: University of Queensland.)
Their test averaged 90% accuracy during the testing of 200
human cancer samples. Furthermore, the researchers found the DNA structure to
be the same in breast, prostate, and bowel cancers, as well as lymphomas, noted
The Conversation.
“We find that DNA polymeric
behavior is strongly affected by differential patterning of methylcytosine
leading to fundamental differences in DNA solvation and DNA-gold affinity
between cancerous and normal genomes,” the researchers wrote in NatureCommunications.“We exploit
these methylscape differences to develop simple, highly sensitive, and
selective electrochemical or one-step assays for detection of cancer.”
Next Steps for the
“Gold Test”
“This approach represents an exciting step forward in
detecting tumor DNA in blood samples and opens up the possibility of a generalized
blood-based test to detect cancer, Ged Brady, PhD, Cancer Research UK
Manchester Institute, told The
Oxford Scientist. “Further clinical studies are required to evaluate
the full clinic potential of the method.”
Researchers said the next step is a larger clinical study to
explore just how fast cancer can be detected. They expressed interest in
finding different cancers in body fluids and at various stages. Another opportunity
they envision is to use the cancer assay with a mobile device.
DiCarlo told USA Today
that such a mobile test could be helpful to clinicians needing fast answers for
people in rural areas. However, he’s also concerned about false positives. “You
don’t expect all tumors to have the same methylation pattern because there’s so
many different ways that cancer can develop,” he told USA Today. “There
are some pieces that don’t exactly align logically.”
The UQ researchers have produced an intriguing study that differs
from other liquid biopsy papers covered by Dark Daily. While their test may need to be used in combination with other
diagnostic tests—MRI, mammography, etc.—it has the potential to one day be used
by clinical laboratories to quickly reveal diverse types of cancers.
As the still-developing pathology profession in China struggles to meet demand, 3rd-party medical laboratory groups, and university/industry arrangements, find opportunities to fill the needs of China’s hospitals
China is currently facing a severe shortage of anatomic pathologists, which blocks patients’ access to quality care. The relatively small number of pathologists are often overworked, even as more patients want access to specialty care for illnesses. Some hospitals in China do not even have pathologists on staff. Thus, they rely on understaffed anatomic pathology departments at other facilities, or they use imaging only for diagnoses.
To serve a population of 1.4 billion people, China has only 29,000 hospitals with seven million beds. Among the healthcare providers, there just 20,000 licensed pathologists, according to the Chinese Pathologist Association. By contrast, recent statistics show that the United States has a population of 326 million people with approximately 18,000 actively practicing pathologists and 5,815 registered hospitals with 898,000 beds.
The largest pathology department in China is at Fudan University Shanghai Cancer Center (FUSCC), a hospital with 1,259 beds in operation and 50 pathologists on staff. News accounts say those pathologists are expected to process 40,000 cases this year, surpassing their 2016 workload by 5,000 cases. The FUSCC pathologists are supported by a small number of supplemental personnel, which include assistants, technicians, and visiting clinicians.
Qifeng Wang, a pathologist at FUSCC, indicated that most leading hospitals in China with average or above-average pathology staffing are experiencing similar barriers as FUSCC. Large hospitals, such as:
“The diagnostic skill level at FUSCC is not that different from that in the U.S.,” Wang told Global HealthCare Insights (GHI). He added, however, that the competent skill level of their staffers is not sufficient to handle the internal workload at FUSCC plus the additional workload referred to them from other facilities.
Though not at the top of the list, as the graphic above illustrates, China is preceded only by Uganda, Sudan, and Malaysia for the number of patients per anatomic pathologist. China has approximately one pathologist per 74,000 people. By contrast, the United States has one pathologist for every 19,000 people. Studies indicate that, globally, the number of pathologists each year is shrinking. (Image copyright: Clinical Laboratory Products)
Patients Forced to Migrate to Receive Diagnoses
Because there are so few pathologists in the vast, heavily-populated country, many Chinese patients travel to major cities to increase their chances of obtaining reliable diagnosis and care, which further overwhelms the system.
The 1,530-bed Yunnan Cancer Hospital in the western city of Kunming handles more than 4,000 cases forwarded to them from other institutions annually. The 14 pathologists at the center also sometimes travel to rural communities to provide anatomic pathology services.
“It’s the complex cases that make it hard to keep up with our workload” said Yonglin Wang, an anatomic pathologist at the Yunnan Cancer Hospital, in the GHI article. The pathologists at Yunnan often refer their more demanding cases to larger hospitals to ensure the best analysis and outcomes for the patients.
Workload, Low Pay, and Lawsuits Discourage Pathology Enrollments
A logical solution to the critical shortage of pathologists in China would be to increase the number of people choosing the profession. However, medical students in the country tend to steer clear of surgical pathology due to the excessive workload, lower pay and status, and the threat of lawsuits relating to improper diagnoses.
To address the demand, a private pathology industry is emerging in China. There are currently more than 300 private medical laboratories located throughout the country. The largest of these businesses is KingMed Diagnostics in Guangzhou. According to their website, the 3rd-party medical laboratory group focuses on medical testing, clinical trials, food and hygiene testing, and scientific research. They examine more than 4,000 pathology cases annually, concentrating on:
“Because pathology has a history of being undervalued in China, the country has a shortage of pathologists trained to diagnose and interpret complex test results in specialized fields of medicine,” said Scott Binder, MD, Senior Vice Chair at UCLA Health in a statement. “Our partnership gives CTI and UCLA the opportunity to save lives by changing that.”
“Our collaboration will offer the people of China oncology, pathology, and laboratory medicine services they can trust. Many of these services are not largely available in China and are needed by physicians and healthcare providers to accurately diagnose and treat their patients,” stated Dr. Sangem Hsu, President of CTI in the UCLA statement.
As the need for pathologists increases worldwide, many countries will struggle to fulfill the demand. This may create even more opportunities for enterprising medical laboratory organizations and anatomic pathology groups who have the wherewithal and determination to make a difference overseas.
Mobile point-of-care (POC) smartphone-based nucleic acid assay allows for quick turn arounds and accurate information in any healthcare setting, including resource limited and remote environments
Clinical laboratory equipment is becoming more effective even as it shrinks in size and cost. One such device has been developed by Ozcan Laboratory Group, headed by UCLA professor Aydogan Ozcan, PhD. It is a portable, smartphone-based mobile lab with sensitivity and reliability on par with large-scale medical laboratory-based equipment.
Ozcan Lab’s portable DNA detection system, according to a UCLA press release, “leverages the sensors and optics of cellphones” and adapts them to read and report the presence of DNA molecules. The sensor uses a new detector dye mixture and reportedly produces a signal that is 10 to 20 times brighter than previous detector dye outputs.
Nucleic acid detecting assays are crucial tools anatomic pathologists use to identify pathogens, detect residual disease markers, and identify treatable mutations of diseases. Due to the need for amplification of nucleic acids for detection with benchtop equipment, there are challenges associated with providing rapid diagnostics outside the clinical laboratory.
The device developed by Ozcan Labs (above) is a “field-portable and cost-effective mobile-phone-based nucleic acid amplification and readout platform [that] is broadly applicable to other real-time nucleic acid amplification tests by similarly modulating intercalating dye performance. It is compatible with any fluorescence-based assay that can be run in a 96-well microplate format, making it especially valuable for POC and resource-limited settings.” (Caption and photo copyright: American Chemical Society.)
Using the new mobile POC nucleic acid testing system developed by Ozcan et al, pathologists can effectively step away from the lab to perform rapid POC testing and accelerated diagnostics onsite, rather than needing to transport materials to and from a central laboratory. The mobile testing assay enables pathologists to carry a medical laboratory with them into the field, or into limited-resource or decentralized testing environments, without sacrificing quality or sensitivity. And according to the ACS Nano article, at a relatively low-cost compared to benchtop nucleic acid testing equipment.
In an article published in Future Medicine, Ozcan and Hatice Ceylan Koydemir, PhD, a post-doctoral researcher in electrical engineering at UCLA, comment on the growing interest in mobile POC diagnostics, stating that smartphone-based devices and platforms have the potential “to be used for early detection and prevention of a variety of health problems.”
According to the article, smartphone-based sensing and imaging platforms have been developed to:
Smartphones, according to Ozcan and Koydemir, have been adapted to a range of biomedical measurement tools, “have the potential to transform traditional uses of imaging, sensing, and diagnostic systems, especially for point-of-care applications and field settings,” and can provide speedy results.
A ‘Highly Stable’ and Sensitive System
The proof-of-concept study of Ozcan Lab’s new smartphone-based detection system and new detector dye mixture was led by Janay E. Kong, PhD in bioengineering at UCLA, with the help of Ozcan and fellow professors Dino Di Carlo, PhD, professor of bioengineering and mechanical and aerospace engineering at UCLA, and Omai Garner, PhD, associate professor of clinical microbiology at the David Geffen School of Medicine at UCLA.
According to an article in Bioscience Technologies, the new smartphone DNA detection system addresses issues with detection of light emitted from intercalator dyes, which are normally “too subtle and unstable for regular cellphone camera sensors.” The new system uses loop-mediated isothermal amplification (LAMP) to amplify DNA in connection with a newly developed dye that uses hydroxynaphthol blue (HNB) as an indicator.
The inclusion of HNB into the dye, according to the original research study, “yields 20 times higher fluorescent signal change over background compared to current intercalating dyes,” making the results bright enough for smartphone camera sensors without “interfering with the nucleic acid amplification process.” The original study reports that the digital LAMP system and use of the HNB intercalating dye, in fact, provided “significantly enhanced performance compared to a benchtop reader with standard LAMP conditions.”
Ozcan labs shows no signs of slowing down their development of mobile POC diagnostic devices. The development of these smartphone-based tools may provide unique and much-needed equipment for clinical pathologists given the rising interest in mobile healthcare worldwide.
In studies, the automated microbial susceptibility testing device for smartphone performed with 98.2% accuracy, meeting FDA criteria
Imagine doing antimicrobial susceptibility testing outside a clinical laboratory. That’s the goal of researchers on the West Coast who are developing a smartphone-based diagnostic device with the capability of performing this type of point-of-care testing (POCT).
This new mobile POCT device is under development at the University of California-Los Angeles (UCLA). It promises to bring antimicrobial susceptibility testing—a routine procedure in the most medical laboratories—to remote, resource-limited areas of the world.
Experts believe compressive sensing could find wide application in medical laboratory and pathology testing, particularly where large amounts of data are generated
Pathologists and medical laboratory managers may soon be working with a new tool in their labs. It is called “Compressive Sensing” (CS) and it is an innovative mathematical approach that quickly and efficiently gets an answer by sampling large volumes of a data.
Currently compressive sensing is used in medical imaging technology. CS reduces radiation and speeds up imaging diagnostics. Some experts familiar with this technology believe that it can be used in those clinical laboratories that are working with new diagnostic technologies that generate large volumes of data. CS could dramatically reduce times to analyze results and lower the cost of expensive tests like whole-genome sequencing. (more…)
