Recent research into transposons within DNA dark matter may produce new biomarkers for clinical laboratory testing and diagnostics
There’s been another interesting development in the study of genetic “dark matter” which may give rise to new biomarkers for clinical laboratory diagnostics and testing. This is worth noting, because biological dark matter has long been considered non-critical and immaterial to the human organism or human evolution. Researchers often refer to it as junk DNA.
However, newly-released research suggests that transposons (aka, transposable elements) contained within our genetic dark matter may play a “critical role in mammalian development,” according to a UC Berkeley news release. Transposons, the release notes, are “viral elements [that] have invaded mammalian genomes for millions of years and currently make up nearly half the DNA in the genomes of all living mammals.”
The study, led by researchers at the University of California, Berkeley, and Washington University in St. Louis, found at least one family of transposons that affected the viability of test mice. They believe the transposon could play a similar role in all mammals—including humans.
Molecular biologist Lin He, PhD (above), led the study conducted at the University of California, Berkeley, and Washington University in St. Louis, which found that bits of DNA once considered “junk” may actually perform important functions, such as ensuring fertility. These findings may one day confirm new biomarkers for clinical laboratory testing. (Photo copyright: MacArthur Foundation.)
How Removal of a Transposon Led to Death
The researchers found that the function of one type of transposon affected whether a mouse fetus could form properly and survive birth. The transposon “regulates the proliferation of cells in the early fertilized embryo and the timing of implantation in the mother’s uterus,” the news release notes.
To perform the research, the scientists removed a specific transposon that controls the proliferation of cells in the early fertilization of an embryo from the mice. After extracting that transposon, half of the mouse pups died before birth.
The researchers then looked at other mammalian species—including humans—and “found virus-derived regulatory elements linked to cell proliferation and timing of embryo implantation, suggesting that ancient viral DNA has been domesticated independently to play a crucial role in early embryonic development in all mammals,” UC Berkeley noted.
The researchers suggest that some of our dark matter DNA has an important function in our embryonic maturation and survival.
“The mouse and humans share 99% of their protein coding genes in their genomes—we are very similar with each other,” said molecular biologist and senior author of the study Lin He, PhD, Associate Professor, Department of Molecular and Cell Biology, UC Berkeley, in the news release.
“So, what constitutes the differences between mice and humans? One of the major differences is gene regulation—mice and humans have the same genes, but they can be regulated differently. Transposons have the capacity to generate a lot of gene regulatory diversity and could help us to understand species-specific differences in the world.”
“The real significance of this story is it tells us how evolution works in the most unexpected manner possible,” said geneticist and study co-author Ting Wang, PhD, Sanford and Karen Loewentheil Distinguished Professor of Medicine, Department of Genetics, Washington University School of Medicine, in the UC Berkeley news release.
“Transposons were long considered useless genetic material, but they make up such a big portion of the mammalian genome. A lot of interesting studies illustrate that transposons are a driving force of human genome evolution. Yet, this is the first example that I know of where deletion of a piece of junk DNA leads to a lethal phenotype, demonstrating that the function of specific transposons can be essential,” he added.
Their research could have implications for human fertility as many miscarriages in humans are due to undiagnosed conditions or have no apparent genetic component.
“If 50% of our genome is non-coding or repetitive—this dark matter—it is very tempting to ask the question whether or not human reproduction and the causes of human infertility can be explained by junk DNA sequences,” he said.
Thus, the UC Berkeley/Washington University study is building on prior research demonstrating that dark matter DNA may not be “junk” after all. More specifically, transposons may eventually have value as biomarkers for clinical laboratory tests and diagnostics.
Of course, additional research and studies are needed to validate these findings and provide greater knowledge about the function of specific transposons. But it’s an intriguing development that’s worth following.
Unlike most other CRISPR/Cas-9 therapies that are ex vivo treatments in which cells are modified outside the body, this study was successful with an in vivo treatment
Use of CRISPR-Cas9 gene editing technology for therapeutic purposes can be a boon for clinical laboratories. Not only is this application a step forward in the march toward precision medicine, but it can give clinical labs the essential role of sequencing a patient’s DNA to help the referring physician identify how CRISPR-Cas9 can be used to edit the patient’s DNA to treat specific health conditions.
Most pathologists and medical lab managers know that CRISPR-Cas9 gene editing technology has been touted as one of the most significant advances in the development of therapies for inherited genetic diseases and other conditions. Now, a pair of biotech companies have announced a milestone for CRISPR-Cas9 with early clinical data involving a treatment delivered intravenously (in vivo).
As with other therapies, determining which patients are suitable candidates for specific treatments is key to the therapy’s success. Therefore, clinical laboratories will play a critical role in identifying those patients who would most likely benefit from a CRISPR-delivered therapy.
Such is the goal of precision medicine. As methods are refined that can correct unwelcome genetic mutations in a patient, the need to do genetic testing to identify and diagnose whether a patient has a specific gene mutation associated with a specific disease will increase.
Cleveland Clinic describes ATTR amyloidosis as a “protein misfolding disorder” involving transthyretin (TTR), a protein made in the liver. The disease leads to deposits of the protein in the heart, nerves, or other organs.
According to Intellia and Regeneron, NTLA-2001 is designed to inactivate the gene that produces the protein.
The interim clinical trial data indicated that one 0.3 mg per kilogram dose of the therapy reduced serum TTR by an average of 87% at day 28. A smaller dose of 0.1 mg per kilogram reduced TTR by an average of 52%. The researchers reported “few adverse events” in the six study patients, “and those that did occur were mild in grade.”
Current treatments, the companies stated, must be administered regularly and typically reduce TTR by about 80%.
“These are the first ever clinical data suggesting that we can precisely edit target cells within the body to treat genetic disease with a single intravenous infusion of CRISPR,” said Intellia President and CEO John Leonard, MD, in a press release. “The interim results support our belief that NTLA-2001 has the potential to halt and reverse the devastating complications of ATTR amyloidosis with a single dose.”
He added that “solving the challenge of targeted delivery of CRISPR-Cas9 to the liver, as we have with NTLA-2001, also unlocks the door to treating a wide array of other genetic diseases with our modular platform, and we intend to move quickly to advance and expand our pipeline.”
“It’s an important moment for the field,” MIT biomedical engineer Daniel Anderson, PhD (above), told Nature. Anderson is Professor, Chemical Engineering and Institute for Medical Engineering and Science at the Koch Institute for Integrative Cancer Research at MIT. “It’s a whole new era of medicine,” he added. Advances in the use of CRISPR-Cas9 for therapeutic purposes will create the need for clinical laboratories to sequence patients’ DNA to help physicians determine the best uses for a CRISPR-Cas9 treatment protocol. (Photo copyright: Massachusetts Institute of Technology.)
In Part 2 of the Phase 1 trial, Intellia plans to evaluate the new therapy at higher doses. After the trial is complete, “the company plans to move to pivotal studies for both polyneuropathy and cardiomyopathy manifestations of ATTR amyloidosis,” the press release states.
Previous clinical trials reported results for ex vivo treatments in which cells were removed from the body, modified with CRISPR-Cas9 techniques, and then reinfused. “But to be able to edit genes directly in the body would open the door to treating a wider range of diseases,” Nature reported.
How CRISPR-Cas9 Works
On its website, CRISPR Therapeutics, a company co-founded by Emmanuelle Charpentier, PhD, a director at the Max Planck Institute for Infection Biology in Berlin, and inventor of CRISPR-Cas9 gene editing, explained that the technology “edits genes by precisely cutting DNA and then letting natural DNA repair processes take over.” It can remove fragments of DNA responsible for causing diseases, as well as repairing damaged genes or inserting new ones.
The therapies have two components: Cas9, an enzyme that cuts the DNA, and Guide RNA (gRNA), which specifies where the DNA should be cut.
Charpentier and biochemist Jennifer Doudna, PhD, Nobel Laureate, Professor of Chemistry, Professor of Biochemistry and Molecular Biology, and Li Ka Shing Chancellor’s Professor in Biomedical and Health at the University of California Berkeley, received the 2020 Nobel Prize in Chemistry for their work on CRISPR-Cas9, STAT reported.
It is important to pathologists and medical laboratory managers to understand that multiple technologies are being advanced and improved at a remarkable pace. That includes the technologies of next-generation sequencing, use of gene-editing tools like CRISPR-Cas9, and advances in artificial intelligence, machine learning, and neural networks.
At some future point, it can be expected that these technologies will be combined and integrated in a way that allows clinical laboratories to make very early and accurate diagnoses of many health conditions.
Even more impressive is that the automated testing lab can reportedly process (with results in four hours) up to 3,000 patient samples daily for SARS-CoV-2, the coronavirus that causes the COVID-19 illness.
“All of our laboratories do PCR every day. But for this test we need to go above and beyond to ensure accurate detection,” said Jennifer Doudna, PhD, IGI Executive Director and UC Berkeley Professor of Molecular and Cell Biology, in an IGA news release.
“We put in place a robotic pipeline for doing thousands of tests per day,” she continued, “with a pipeline for managing the data and getting it back to clinicians. Imagine setting that up in a couple of weeks. It’s really extraordinary and something I’ve never seen in my career.”
Robert Sanders, UC Berkeley’s Manager Science Communications, told Dark Daily the COVID-19 lab performs about 180 tests per day and has tested 1,000 people so far—80% of the samples came from the campus community. About 1.5% to 4% of the tests were found to be positive for the SARS-CoV-2 coronavirus among the groups tested.
“We hope other academic institutions will set up testing labs too,” he said.
How Did Berkeley Set Up a COVID-19 Diagnostic Lab So Fast?
To get up and running quickly, university officials drew from the campus and surrounding business community to equip and operate the laboratory, as well as, train researchers to do clinical analysis of patient samples.
Though the methodology to test for the coronavirus—isolating RNA from a biological sample and amplifying it with PCR—is standard fare in most research labs worldwide, including at UC Berkeley, the campus’ research labs were shuttered due to the spread of the coronavirus.
IGI reached out to the idle labs for their high-throughput PCR systems to start-up the lab. Through its partnership with University Health Services and local and national companies, IGI created an automated sample intake and processing workflow.
Additionally, several research scientists who were under government-mandated stay-at-home orders made themselves available. “My own research is shut down—and there’s not very much I can do other than stay in my home … finally I’m useful,” said PhD candidate Holly Gildea in a Berkeleyside article which noted that about 30 people—mostly doctoral students and postdoctoral researchers—are being trained to oversee the process and monitor the automated equipment.
Postdoctoral fellows Jenny Hamilton (left) and Enrique Shao (right) with an automated liquid-handling robot (Hamilton Microlab STAR), which will be used to analyze swabs from patients to diagnose COVID-19. Hamilton and Shao volunteered to train to become CLIA certified so as to process patient samples. When analyzing real samples from patients, they would be wearing full personal protective equipment (PPE), including mask, face shield, gown and gloves. (Photo and caption copyright: Max and Jules Photography/UC Berkeley.)
Federal and State Authorities Remove Hurdles
In her article, “Blueprint for a Pop-up SARS-CoV-2 Testing Lab,” published on the medRxiv servers, Doudna summarized “three regulatory developments [that] allowed the IGI to rapidly transition its research laboratory space into a clinical testing facility.
“The second was California Governor Newsom’s Executive Order N-25-20, which modified the requirements for clinical laboratory personnel running diagnostic tests for SARS-CoV-2 in a certified laboratory.
“The third was increased flexibility and expediency at the state and federal levels for certification and licensure requirements for clinical laboratory facilities under the Clinical Laboratory Improvement Amendments (CLIA) program. Under these emergency conditions, the California Department of Public Health (CDPH) was willing to temporarily extend—once the appropriate regulatory requirements have been fulfilled—an existing CLIA certificate for high-complexity testing to a non-contiguous building on our university campus.”
“These developments,” wrote Doudna, “enabled us to develop and validate a laboratory-developed test (LDT) for SARS-CoV-2, extend the UC Berkeley Student Health Center’s clinical laboratory license to our laboratory space, and begin testing patient samples.”
Lessons Learned Implementing a Pop-Up COVID-19 Testing Laboratory
“Our procedures for implementing the technical, regulatory, and data management workstreams necessary for clinical sample processing provide a roadmap to others in setting up similar testing centers,” she wrote.
Learned strategies Doudna says could aid other academic research labs transform to a “SARS-CoV-2 Diagnostic Testing Laboratory include:
Leveraging licenses from existing CLIA-certified labs;
Following FDA authorized testing procedures;
Using online HIPAA training;
Managing supply chain “bottlenecks” by using donated equipment;
Adopting in-house sample barcoding;
Adapting materials, such as sampling tubes, to work with donated equipment;
Cost of equipment and supplies (not including staff) was $550,000, with a per test cost of $24, Doudna noted.
“As the COVID-19 pandemic continues, our intention is to provide both PCR-based diagnostic testing and to advance research on asymptomatic transmission, analyze virus sequence evolution, and provide benchmarking for new diagnostic technologies,” she added.
Medical laboratory leaders understand that the divide between clinical and research laboratories is not easy to surmount. Nevertheless, UC Berkley’s IGI pulled it off. The lab marshaled resources as it took on the novel coronavirus, quickly developed and validated a test workflow, and assembled and trained staff to analyze tests with fast TAT to providers, students, and area residents. There’s much that can be learned from UC Berkeley IGI’s accomplishments.
The 80 scientists and engineers that comprise the consortium believe synthetic biology can address key challenges in health and medicine, but technical hurdles remain
Synthetic biology now has a 20-year development roadmap. Many predict this fast-moving field of science will deliver valuable products that can be used in diagnostics—including clinical laboratory tests, therapeutics, and other healthcare products.
Eighty scientists from universities and companies around the world that comprise the Engineering Biology Research Consortium (EBRC) recently published the 20-year roadmap. They designed it to “provide researchers and other stakeholders (including government funders)” with what they hope will be “a go-to resource for engineering/synthetic biology research and related endeavors,” states the EBRC Roadmap website.
Medical laboratories and clinical pathologists may soon have new tools and therapies for targeting specific diseases. The EBRC defines synthetic biology as “the design and construction of new biological entities such as enzymes, genetic circuits, and cells or the redesign of existing biological systems. Synthetic biology builds on the advances in molecular, cell, and systems biology and seeks to transform biology in the same way that synthesis transformed chemistry and integrated circuit design transformed computing.”
Synthetic biology is an expanding field and there are predictions that it may produce research findings that can be adapted for use in clinical pathology diagnostics and treatment for chronic diseases, such as cancer.
Another goal of the roadmap is to encourage federal
government funding for synthetic biology.
“The question for government is: If all of these avenues are now open for biotechnology development, how does the US stay ahead in those developments as a country?” said Douglas Friedman, EBRC’s Executive Director, in a news release. “This field has the ability to be truly impactful for society and we need to identify engineering biology as a national priority, organize around that national priority, and take action based on it.”
Designing or Redesigning Life Forms for Specific
Applications
Synthetic biology is an interdisciplinary field that combines
elements of engineering, biology, chemistry, and computer science. It enables
the design and construction of new life forms—or redesign of existing ones—for
a multitude of applications in medicine and other fields.
Another recent example comes from the Wyss Institute at Harvard. Scientist there developed a direct-to-consumer molecular diagnostics platform called INSPECTR that, they say, uses programmable synthetic biosensors to detect infectious pathogens or host cells.
The Wyss Institute says on its website that the platform can
be packaged as a low-cost, direct-to-consumer test similar to a home pregnancy
test. “This novel approach combines the specificity, rapid development, and
broad applicability of a molecular diagnostic with the low-cost, stability, and
direct-to-consumer applicability of lateral flow immunoassays.”
In March, Harvard announced that it had licensed the technology to Sherlock Biosciences.
Howard Salis, PhD (above), Associate Professor of biological engineering and chemical engineering at Pennsylvania State University (Penn State), co-chaired the EBRC Roadmapping Working Group that produced the roadmap. In a Penn State news story, Salis explained synthetic biology’s potential. “There are both traditional and startup companies leveraging synthetic biology technologies to develop novel biotech products,” he said. “Organisms that produce biorenewable materials; diagnostics to detect the Zika virus, Ebola and tuberculosis; and soil bacteria that fix nitrogen into ammonia for improved plant growth.” (Photo copyright: Twitter.)
Fundamental Challenges with Synthetic Biology
The proponents of synthetic biology hope to make it easier
to design and build these systems, in much the same way computer engineers
design integrated circuits and processors. The EBRC Roadmap may help scientist
worldwide achieve this goal.
However, in “What is Synthetic/Engineering Biology?” the EBRC also identifies the fundamental challenges facing the field. Namely, the complexity and unpredictability inherent in biology, and a limited understanding of how biological components interact.
The EBRC roadmap report, “Engineering Biology: A Research
Roadmap for the Next-Generation Bioeconomy,” covers five categories of applications:
Health and medicine are of primary interest to pathologists.
Synthetic Biology in Health and Medicine
The Health and Medicine section of the report identifies
four broad societal challenges that the EBRC believes can be addressed by
synthetic biology. For each, the report specifies engineering biology
objectives, including efforts to develop new diagnostic technologies. They
include:
Existing and emerging infectious diseases: Objectives include development of tools for treating infections, improving immunity, reducing dependence on antibiotics, and diagnosing antimicrobial-resistant infections. The authors also foresee tools for rapid characterization and response to “known and unknown pathogens in real time at population scales.”
Non-communicable diseases and disorders, including cancer, heart disease, and diabetes: Objectives include development of biosensors that will measure metabolites and other biomolecules in vivo. Also: tools for identifying patient-specific drugs; tools for delivering gene therapies; and genetic circuits that will foster tissue formation and repair.
Environmental health threats, such as toxins, pollution, and injury: Objectives include systems that will integrate wearable tech with living cells, improve interaction with prosthetics, prevent rejection of transplanted organs, and detect and repair of biochemical damage.
Healthcare access and personalized medicine: The authors believe that synthetic biology can enable personalized treatments and make new therapies more affordable.
Technical Themes
In addition to these applications, the report identifies
four “technical themes,” broad categories of technology that will spur the
advancement of synthetic biology:
Gene editing, synthesis, and assembly: This refers to tools for producing chromosomal DNA and engineering whole genomes.
Biomolecule, pathway, and circuit engineering: This “focuses on the importance, challenges, and goals of engineering individual biomolecules themselves to have expanded or new functions,” the roadmap states. This theme also covers efforts to combine biological components, both natural and non-natural, into larger, more-complex systems.
Host and consortia engineering: This “spans the development of cell-free systems, synthetic cells, single-cell organisms, multicellular tissues and whole organisms, and microbial consortia and biomes,” the roadmap states.
Data Integration, modeling, and automation: This refers to the ability to apply engineering principles of Design, Build, Test and Learn to synthetic biology.
The roadmap also describes the current state of each
technology and projects likely milestones at two, five, 10, and 20 years into
the future. The 2- and 5-year milestones are based on “current or recently
implemented funding programs, as well as existing infrastructure and facilities
resources,” the report says.
The longer-term milestones are more ambitious and may
require “significant technical advancements and/or increased funding and
resources and new and improved infrastructure.”
Synthetic biology is a significant technology that could
bring about major changes in clinical pathology diagnostics and treatments.
It’s well worth watching.
“On-a-chip” devices continue to advance and medical laboratories will be natural repositories for patient data as the technology continues to improve
Dark Daily has predicted that the future of clinical laboratory testing will include highly complex multi-analyte test panels. The biomarkers, however, could number in the hundreds or thousands. So, it’s interesting to see new research by a Massachusetts Institute of Technology (MIT) team currently developing a multi-biomarker organ test device for clinical purposes.
Motivated by the costly failure of animal testing efforts to develop drug safety and efficacy in humans, the MIT research engineers created a microfluidic platform technology they dubbed “physiome-on-a-chip,” or more colloquially, “body-on-a-chip.” Their goal is to identify drug reaction in different cell groups within the body (in vivo).
They acknowledged contributions of in vitro microphysiological systems (MPSs), AKA “organ-on-a-chip” (OOC) systems. They note, however, in their paper published in Scientific Reports, that more complex systems that interconnect and receive data from multiple MPSs are needed due to increasing limitations arising from drugs’ “lack of efficacy” rather than toxicity.
“Here we describe the development and implementation of multi-MPS platforms, AKA physiome-on-a-chip, supporting four-way, seven-way, and 10-way MPS interactions for several weeks,” the MIT engineers wrote.
Though MIT’s new technology needs further research and development time, as well as clinical trials, this type of chip design and its ability to scale is a positive development and progress toward Dark Daily’s prediction. Once finalized, it could be adopted in medical laboratories for many types of diagnostic testing purposes.
Researchers Motivated to Improve Drug Efficacy
According to an MIT news release, “MIT engineers have developed new technology that could be used to evaluate new drugs and detect possible side effects before the drugs are tested in humans. Using a microfluidic platform that connects engineered tissues from up to 10 organs, the researchers can accurately replicate human organ interactions for weeks at a time, allowing them to measure the effects of drugs on different parts of the body.”
The “body-on-a-chip” technology, MIT says, is aimed at determining how drugs may affect one organ while also having side effects on others.
“Some of these effects are really hard to predict from animal models because the situations that lead to them are idiosyncratic. With our chip, you can distribute a drug and then look for the effects on other tissues and measure the exposure and how it is metabolized,” said Linda Griffith, PhD, Professor of Teaching Innovation at MIT’s School of Engineering, and a senior author of the study, in the news release.
According to MIT, factors affecting the effectiveness of pharmaceuticals may include:
Genetics;
Environment;
Personal lifestyles; and,
Interactions with other drugs.
TechCrunch called the study “unprecedented,” pointing to the platform’s connection of so many tissues and the technology’s ability to keep them stable for weeks.
“An advantage of our platform is that we can scale it up or down and accommodate a lot of different configurations,” Linda Griffith, PhD, MIT Professor, MIT School of Engineering, told Science Daily. “I think the field is going to go through a transition where we start to get more information out of a three-organ or four-organ system, and it will start to become cost-competitive because the information you’re getting is so much more valuable.” (Photo copyright: MacArthur Foundation.)
How “Body-on-a-Chip” Works
“Body-on-a-chip” is about the size of a tablet computer and links 10 organ types, including: liver, lung, gut, endometrium, brain, heart, pancreas, kidney, skin, and skeletal muscle.
Using microfluidic platform technology, the researchers placed one- to two-million cells from human tissue samples into the device and then pushed fluid through the chip to resemble blood flow, the Daily Mail reported, adding that MIT’s MPS platform design features:
Compartments made from a plastic block;
Passages for fluid to move (as a circulatory system does) between the compartments;
A water reservoir to limit fluid evaporation; and,
Ability to monitor flow of molecular exchanges and drug distribution.
Essentially, using the MIT device, a drug can be introduced to one organ, processed normally, and then passed to other organs for processing and use in other ways, TechCrunch summarized.
The physiome-on-a-chip system (above schematic) comprises bioengineered devices that nurture many interconnected 3D MPSs representing specified functional behaviors of each organ of interest, designed to capture essential features of in vivo physiology based on quantitative systems models tailored for individual applications such as drug fate or disease modeling. This technology could eventually be utilized for clinical laboratory and anatomic pathology testing. (Image and caption copyright: Victor O. Leshyk/Scientific Reports.)
Drug Delivery, Effects on Multiple Tissues Noted in MIT Study
The MIT researcher engineers reported these findings and accomplishments:
Delivering a drug to the gastrointestinal tissue;
Replicating digesting a drug;
Observing as a drug was transported to other tissues and metabolized;
Measuring a drug’s path; and,
Noting effects of a drug on different tissues and how drugs break down.
“The huge potential of MPS technology is revealed by connecting multiple organ chips in an integrated system for in vitropharmacology. This study beautifully illustrates that multi-MPS ‘physiome-on-a-chip’ approaches, which combine the genetic background of human cells with physiologically relevant tissue-to-media volumes, allow accurate prediction of drug pharmacokinetics and drug absorption, distribution, metabolism, and excretion,” said Kevin Healy, PhD, Professor of Bioengineering and Materials Science and Engineering, at University of California Berkeley in the MIT news release. Healy was not involved in the research.
Unique Device Design
In addition to making it possible to study so many different tissue types, the device design, according to MIT, is unique for these reasons:
Its open microfluidic system, rather than a closed system, means the lid can be removed to manipulate tissue samples;
Instead of external pumps common in closed systems, the MIT team used “on-board pumps” to control flow of liquid between the organs; and,
The pumps used enabled larger engineered tissues, such as those from tumors in an organ, to be assessed.
The MIT engineers next plan to focus on specific organs—including the brain, liver, and gastrointestinal tissue—to model Parkinson’s disease, Digital Trends reported.
As healthcare providers and medical laboratories adopt precision medicine, MIT’s contributions are both timely and important. The ability to accommodate many different configurations in one platform is impressive, and something Dark Daily has been anticipating.
