Apr 18, 2018 | Instruments & Equipment, Laboratory Instruments & Laboratory Equipment, Laboratory Management and Operations, Laboratory News, Laboratory Operations, Laboratory Pathology, Laboratory Testing, Management & Operations
Three innovative technologies utilizing CRISPR-Cas13, Cas12a, and Cas9 demonstrate how CRISPR might be used for more than gene editing, while highlighting potential to develop new diagnostics for both the medical laboratory and point-of-care (POC) testing markets
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is in the news again! The remarkable genetic-editing technology is at the core of several important developments in clinical laboratory and anatomic pathology diagnostics, which Dark Daily has covered in detail for years.
Now, scientists at three universities are investigating ways to expand CRISPR’s use. They are using CRISPR to develop new diagnostic tests, or to enhance the sensitivity of existing DNA tests.
One such advancement improves the sensitivity of SHERLOCK (Specific High Sensitivity Reporter unLOCKing), a CRISPR-based diagnostic tool developed by a team at MIT. The new development harnesses the DNA slicing traits of CRISPR to adapt it as a multifunctional tool capable of acting as a biosensor. This has resulted in a paper-strip test, much like a pregnancy test, that can that can “display test results for a single genetic signature,” according to MIT News.
Such a medical laboratory test would be highly useful during pandemics and in rural environments that lack critical resources, such as electricity and clean water.
One Hundred Times More Sensitive Medical Laboratory Tests!
Co-lead authors Jonathan Gootenberg, PhD Candidate, Harvard University and Broad Institute; and Omar Abudayyeh, PhD and MD student, MIT, published their findings in Science. They used CRISPR Cas13 and Cas12a to chop up RNA in a sample and RNA-guided DNA binding to target genetic sequences. Presence of targeted sequences is then indicated using a paper-based testing strip like those used in consumer pregnancy tests.
MIT News highlighted the high specificity and ease-of-use of their system in detecting Zika and Dengue viruses simultaneously. However, researchers stated that the system can target any genetic sequence. “With the original SHERLOCK, we were detecting a single molecule in a microliter, but now we can achieve 100-fold greater sensitivity … That’s especially important for applications like detecting cell-free tumor DNA in blood samples, where the concentration of your target might be extremely low,” noted Abudayyeh.
“The [CRISPR] technology demonstrates potential for many healthcare applications, including diagnosing infections in patients and detecting mutations that confer drug resistance or cause cancer,” stated senior author Feng Zhang, PhD. Zhang, shown above in the MIT lab named after him, is a Core Institute Member of the Broad Institute, Associate Professor in the departments of Brain and Cognitive Sciences and Biological Engineering at MIT, and a pioneer in the development of CRISPR gene-editing tools. (Photo copyright: MIT.)
Another unique use of CRISPR technology involved researchers David Liu, PhD, and Weixin Tang, PhD, of Harvard University and Howard Hughes Medical Institute (HHMI). Working in the Feng Zhang laboratory at the Broad Institute, they developed a sort of “data recorder” that records events as CRISPR-Cas9 is used to remove portions of a cell’s DNA.
They published the results of their development of CRISPR-mediated analog multi-event recording apparatus (CAMERA) systems, in Science. The story was also covered by STAT.
“The order of stimuli can be recorded through an overlapping guide RNA design and memories can be erased and re-recorded over multiple cycles,” the researchers noted. “CAMERA systems serve as ‘cell data recorders’ that write a history of endogenous or exogenous signaling events into permanent DNA sequence modifications in living cells.”
This creates a system much like the “black box” recorders in aircraft. However, using Cas9, data is recorded at the cellular level. “There are a lot of questions in cell biology where you’d like to know a cell’s history,” Liu told STAT.
While researchers acknowledge that any medical applications are in the far future, the technology holds the potential to capture and replay activity on the cellular level—a potentially powerful tool for oncologists, pathologists, and other medical specialists.
Using CRISPR to Detect Viruses and Infectious Diseases
Another recently developed technology—DNA Endonuclease Targeted CRISPR Trans Reporter (DETECTR)—shows even greater promise for utility to anatomic pathology groups and clinical laboratories.
Also recently debuted in Science, the DETECTR system is a product of Jennifer Doudna, PhD, and a team of researchers at the University of California Berkeley and HHMI. It uses CRISPR-Cas12a’s indiscriminate single-stranded DNA cleaving as a biosensor to detect different human papillomaviruses (HPVs). Once detected, it signals to indicate the presence of HPV in human cells.
Despite the current focus on HPVs, the researchers told Gizmodo they believe the same methods could identify other viral or bacterial infections, detect cancer biomarkers, and uncover chromosomal abnormalities.
Future Impact on Clinical Laboratories of CRISPR-based Diagnostics
Each of these new methods highlights the abilities of CRISPR both as a data generation tool and a biosensor. While still in the research phases, they offer yet another possibility of improving efficiency, targeting specific diseases and pathogens, and creating new assays and diagnostics to expand medical laboratory testing menus and power the precision medicine treatments of the future.
As CRISPR-based diagnostics mature, medical laboratory directors might find that new capabilities and assays featuring these technologies offer new avenues for remaining competitive and maintaining margins.
However, as SHERLOCK demonstrates, it also highlights the push for tests that produce results with high-specificity, but which do not require specialized medical laboratory training and expensive hardware to read. Similar approaches could power the next generation of POC tests, which certainly would affect the volume, and therefore the revenue, of independent clinical laboratories and hospital/health system core laboratories.
—Jon Stone
Related Information:
Multiplexed and Portable Nucleic Acid Detection Platform with Cas13, Cas12a, and Csm6
Rewritable Multi-Event Analog Recording in Bacterial and Mammalian Cells
CRISPR-Cas12a Target Binding Unleashes Indiscriminate Single-Stranded DNase Activity
Researchers Advance CRISPR-Based Tool for Diagnosing Disease
CRISPR Isn’t Just for Gene Editing Anymore
CRISPR’s Pioneers Find a Way to Use It as a Glowing Virus Detector
With New CRISPR Inventions, Its Pioneers Say, You Ain’t Seen Nothin’ Yet
New CRISPR Tools Can Detect Infections Like HPV, Dengue, and Zika
Breakthrough DNA Editing Tool May Help Pathologists Develop New Diagnostic Approaches to Identify and Treat the Underlying Causes of Diseases at the Genetic Level
CRISPR-Related Tool Set to Fundamentally Change Clinical Laboratory Diagnostics, Especially in Rural and Remote Locations
Harvard Researchers Demonstrate a New Method to Deliver Gene-editing Proteins into Cells: Possibly Creating a New Diagnostic Opportunity for Pathologists
Nov 17, 2017 | Laboratory Instruments & Laboratory Equipment, Laboratory Management and Operations, Laboratory News, Laboratory Operations, Laboratory Pathology, Laboratory Testing, Management & Operations
Ongoing research at the University of Washington promises new methods for identifying and cataloging large numbers of cells quickly, which could lead to more individualized treatments in support of precision medicine initiatives
Researchers have found a new method for identifying specific cell types by groups, a breakthrough that some experts say could lead to new and more accurate methods for diagnosing and treating disease in individual patients, and new tools for fighting cancer and other chronic diseases. If this happens, both clinical laboratories and anatomic pathology labs would benefit from this technology.
A study published in the journal Science titled, “Comprehensive Single-Cell Transcriptional Profiling of a Multicellular Organism,” describes advances in cataloging cells that are much faster than the traditional method of using a microscope. The research is still in the experimental stage, but it is being hailed as both exciting and promising by experts in the field.
Barcoding Large Numbers of Cells for Viewing Simultaneously
To test their method, researchers from the University of Washington (UW) sequenced each cell of an individual Caenorhabditis elegans (nematode). Nematodes are transparent roundworms that have been extensively studied making them ideal for the UW study, since much information exists about their cellular structure.
The researchers developed a strategy they dubbed “single-cell combinatorial indexing RNA sequencing,” or “sci-RNA-seq” for short, to profile the transcriptomes of nuclei. A New York Times article on the study describes sci-RNA-seq as a kind of barcoding that shows which genes are active in each cell.
“We came up with this scheme that allows us to look at very large numbers of cells at the same time, without ever isolating a single cell,” noted Jay Shendure, PhD, MD, Professor of Genome Sciences at the University of Washington.
The UW researchers used sci-RNA-seq to measure the activity in 42,035 cells at the same time. Once all of the cells were tagged, or barcoded, the researchers broke them open so the sequences of tags could be read simultaneously.
“We defined consensus expression profiles for 27 cell types and recovered rare neuronal cell types corresponding to as few as one or two cells,” wrote the researchers in their published study.
Because such a rich body of research on nematodes exists, the researchers could easily compare the results that got to those procured in previous studies.
Jay Shendure, MD, PhD (above), Professor of Genomic Sciences at the University of Washington, and an Investigator at the Howard Hughes Medical Institute, was just a graduate student when his work with genetics led to the development of today’s next-generation gene sequencing technologies. His new cell-type identification technology could eventually be used by clinical laboratories and anatomic pathology groups to diagnose disease. (Photo copyright: Howard Hughes Medical Institute.)
One Giant Leap for Medical Diagnostics
Identifying cell types has been a challenge to the medical community for at least 150 years. It is important for scientists to understand the most basic unity of life, but it has only been in the last few years that researchers have been able to measure transcriptomes in single cells. Even though the research so far is preliminary, the scientific community is excited about the results because—should the methods be refined—it could mean a great leap forward in the field of cell-typing.
However, the study did not identify all of the cell types known to exist in a nematode. “We don’t consider this a finished project,” stated Shendure in a New York Times article.
Nevertheless, researchers not associated with the study feel confident about the promise of the work. Cori Bargmann, PhD, a neurobiologist and Torsten N. Wiesel Professor at The Rockefeller University, and an Investigator for the Howard Hughes Medical Institute from 1995 to 2016, states that the results “will be valuable for me and for the whole field,” adding, “Of course, there’s more to do, but I am pretty optimistic that this can be solved.”
“The ability to measure the transcriptomes of single cells has only been feasible for a few years, and is becoming an extremely popular assay,” wrote Valentine Svensson, predoctoral fellow et al, of EMBL-EBI in the UK, in a paper titled, “Exponential Scaling of Single-Cell RNA-Seq in the Last Decade.” He added, “Technological developments and protocol improvements have fueled a consistent exponential increase in the numbers of cells studied in single cell RNA-seq analyses.” The UW research represents another such improvement.
Human Cell Atlas—Understanding the Basis of Life Itself
There are approximately 37-trillion cells in the human body and scientists have long believed there are 200 different cell types. Thus, there is an enormous difference between a nematode and a human body. For medical science to benefit from these studies, massive numbers of human cells must be identified and understood. Efforts are now underway to catalog and map them all.
The Human Cell Atlas (HCA) is an effort to catalog all of those disparate cell types. The mission of HCA is “To create comprehensive reference maps of all human cells—the fundamental units of life—as a basis for both understanding human health and diagnosing, monitoring, and treating disease.”
According to HCA’s website, having the atlas completed will impact our understanding of every aspect of human biology, from immunologic diseases to cancer. Aviv Regev, PhD, of the Broad Institute at MIT, who also is an Investigator with the HHMI and is co-chair of the organizing committee at the Human Cell Atlas notes, “The human cell atlas initiative will work through organs, tissues, and systems.”
One of the many complications of creating the atlas is that the locations of cells vary in humans. “The trick,” Regev noted in the New York Times article, “is to relate cells to the place they came from.” This would seem to be at the heart of the UW researchers’ new method for “barcoding” groups of cells.
Just as sequencing the entire human genome has brought about previously unimagined advances in science, so too will the research being conducted at the University of Washington, as well as the completion of the Human Cell Atlas Project. It is possible that pursuing the goal of quickly identifying and cataloging cells will lead to advances in anatomic pathology, and allow medical laboratory scientists to better interpret genetic variants, ultimately bringing healthcare closer to the delivery of true precision medicine.
—Dava Stewart
Related Information:
Comprehensive Single-Cell Transcriptional Profiling of a Multicellular Organism
A Speedier Way to Catalog Human Cells (All 37 Trillion of Them)
Exponential Scaling of Single-Cell RNA-Seq In the Last Decade
Human Cell Atlas
Genetic Fingerprint Helps Researchers Identify Aggressive Prostate Cancer from Non-Aggressive Types and Determine if Treatment Will Be Effective
Big Data Projects at Geisinger Health Are Beginning to Help Physicians Speed Up Diagnosis and Improve Patient Care
Biomarker Trends Are Auspicious for Pathologists and Clinical Laboratories
Pathologists and Clinical Laboratories May Soon Have a Test for Identifying Cardiac Patients at Risk from Specific Heart Drugs by Studying the Patients’ Own Heart Cells
Jun 14, 2017 | Digital Pathology, Instruments & Equipment, Laboratory Instruments & Laboratory Equipment, Laboratory Management and Operations, Laboratory News, Laboratory Operations, Laboratory Pathology, Laboratory Testing, Management & Operations
New discoveries about the genetics of prostate cancer could lead to better tools for diagnosing the disease and selecting effective therapies based on each patient’s specific physiology
In recent decades, the biggest challenge for urologists, and for the pathologists who diagnosed the prostate tissue specimens they referred, has been how to accurately differentiate between non-aggressive prostate cancer, which can exist for decades with no apparent symptoms, and aggressive prostate cancer that kills quickly.
Thus, a research study that has identified unique genetic features within prostate cancer that can help determine if the cancer is aggressive or not, and whether certain drugs may be effective, is good news for men, for urologists, and for the clinical laboratories that will be called upon to perform testing.
These types of breakthroughs bring precision medicine ever closer to having viable tools for effective diagnosis of different types of cancer.
Genetic Fingerprints of Cancer Tumor Types
One such study into the genetic pathways of prostate cancer is bringing precision medicine ever-closer to the anatomic pathology laboratory. Researchers from the Princess Margaret Cancer Centre, which is associated with the University of Toronto Faculty of Medicine, have discovered that some tumors in prostate cancer have a genetic fingerprint that may indicate whether or not the disease will become more aggressive and less responsive to treatment.
Robert Bristow, MD, PhD, and Paul Boutros, PhD, conducted a study of nearly 500 Canadian men who had prostate cancer. Published in the journal Nature, the researchers examined the genetic sequences of those tumors, looking for differences between those that responded to surgery or radiation and those that did not.
In the video above, Dr. Robert Bristow, clinician-scientist at Princess Margaret Cancer Centre, discusses the findings of a key piece in the genetic puzzle that explains why men born with a BRCA2 mutation develop aggressive prostate cancer. (Caption and photo copyright: University Health Network/Princess Margaret Cancer Centre.)
According to a FierceBiotech article, approximately 30% of men who have a type of prostate cancer thought to be curable eventually develop an aggressive metastatic type of the disease. About half of the men who developed a metastatic form of cancer had mutations to three specific genes:
“This information gives us new precision about the treatment response of men with prostate cancer and important clues about how to better treat one set of men versus the other to improve cure rates overall,” stated Bristow in a University Health Network (UHN) press release.
In another study, researchers looked at 15 patients with BRCA2-inheritied prostate cancer and compared the genomic sequences of those tumors to a large group of sequences from tumors in less-aggressive cancer cases. According to a ScienceDaily news release, they found that only 2% of men with prostate cancer have the BRCA2-inherited type.
Knowing what type of cancer a man has could be critically important for clinicians tasked with prescribing the most efficient therapies.
“The pathways that we discovered to be abnormal in the localized BRCA2-associated cancers are usually only found in general population cancers when they become resistant to hormone therapy and spread through the body,” noted Bristow in the ScienceDaily release. If clinicians knew from diagnosis that the cancer is likely to become aggressive, they could choose a more appropriate therapy from the beginning of treatment.
Genetic Mutations Also Could Lead to Breast and Brain Cancer Treatments
BRCA mutations have also been implicated in breast, ovarian, and pancreatic cancers, among some other types. The knowledge that BRCA1 and BRACA2 mutations could indicate a more aggressive cancer is likely to spark investigation into whether poly ADP ribose polymerase (PARP) inhibitors could be used as an effective therapy.
PARP inhibitors are increasingly of interest to scientists. In addition to being used to treat some BRCA1/BRCA2-implicated cancers, two recent studies show that it could be effective in treating brain cancer with low-grade gliomas that involve a mutation to the gene isocitrate dehydrogenase (IDH), according to an article published by the National Cancer Institute and the National Institutes of Health (NIH).
Researchers of the study published in the journal Clinical Cancer Research investigated how PARP inhibitors impact DNA repair in gliomas.
Researchers of the study published in the journal Science Translational Medicine stated that they “demonstrate mutant IDH1-dependent PARP inhibitor sensitivity in a range of clinically relevant models, including primary patient-derived glioma cells in culture and genetically matched tumor xenografts in vivo.”
According to the UHN press release, the next step in using the knowledge that BRCA1 and BRCA2 may indicate a more aggressive prostate cancer is for researchers to create a diagnostic tool that can be used to determine what type of prostate cancer a man has. They expect the process to take several years. “This work really gives us a map to what is going on inside a prostate cancer cell, and will become the scaffold on which precision therapy will be built,” Boutros stated in a Prostate Cancer Canada news release.
Unlocking Knowledge That Leads to Accurate Diagnoses and Treatments
Research that furthers precision medicine and allows clinicians to choose the most appropriate treatment for individuals shows how quickly scientists are applying new discoveries. Every new understanding of metabolic pathways that leads to a new diagnostic tool gives clinicians and the patients they treat more information about the best therapies to select.
For the anatomic pathology profession, this shows how ongoing research into the genetic makeup of prostate cancer is unlocking knowledge about the genetic and metabolic pathways involved in this type of cancer. Not only does this help in diagnosis, but it can guide the selection of appropriate therapies.
On the wider picture, the research at the Princess Margaret Cancer Centre is one more example of how scientists are rapidly applying new knowledge about molecular and genetic processes in the human body to identify new ways to more accurately diagnose disease and select therapies.
—Dava Stewart
Related Information:
Genomic Hallmarks of Localized, Non-Indolent Prostate Cancer
Newly Discovered Genetic Fingerprint for Prostate Cancer Promises to Personalize Treatment
Prostate Cancer Team Cracks Genetic Code to Show Why Inherited Disease Can Turn Lethal
PARP Inhibitors May Be Effective in Brain, Other Caners with IDH Mutations
Chemosensitivity of IDH1-Mutated Gliomas Due to an Impairment in PARP1-Mediated DNA Repair
2-Hydroxyglutarate Produced by Neomorphic IDH Mutations Suppresses Homologous Recombination and Induces PARP Inhibitor Sensitivity
Prostate Cancer Researchers Find Genetic Fingerprint Identifying How, When Disease Spreads
Scientists Identify DNA Signature Linked to Prostate Cancer Severity
Jun 8, 2016 | Digital Pathology, Instruments & Equipment, Laboratory Management and Operations, Laboratory News, Laboratory Operations, Laboratory Pathology, Laboratory Testing
U.S. Patent and Trademark Office will hold hearings to determine whether University of California Berkeley, or Broad Institute of Harvard and MIT, should receive patents for new genomic engineering technique
In the race to master gene-editing in ways that will advance genetic medicine and patient care, one of the hottest technologies is CRISPR, which stands for Clustered Regularly Interspaced Short Palindromic Repeats. But now a patent fight has the potential to complicate how pathologists and other scientists use this exciting technology.
This dispute over the CRISPR patent—a tool that has been hailed as one of the biggest biotech breakthroughs of the decade—will likely be settled in the coming months by the United States Patent and Trademark Office (USPTO).
The USPTO will be reviewing key patents awarded for what is called CRISPR/Cas9. The technology is already generating novel therapies for diseases, which should create new opportunities for pathologists and medical laboratories. (more…)
Feb 5, 2016 | Laboratory Pathology, Laboratory Testing
Called ‘ViroCap,’ this new diagnostic technology is able to discover more viruses in patient samples, as compared to PCR genome sequencing tests
It could be the ultimate multi-analysis medical laboratory test ever. Researchers at Washington University School of Medicine in St. Louis have developed a diagnostic test that they claim tests for any virus infecting people and animals.
The new test, called ViroCap, detects viruses that standard tests based on genome sequencing cannot, according to a university statement.
Viruses Make for a Popular Research Subject
Are virus tests going, well, viral? It was just a few weeks ago that Dark Daily reported on research at Howard Hughes Medical Institute (HHMI) aimed at unlocking virus detection beyond one pathogen at a time. (See Dark Daily, “Researchers at Howard Hughes Medical Institute Develop Blood Test That Reveals a Patient’s Viral History; Could Reduce Unnecessary Clinical Laboratory Testing,” December, 30, 2015.)
The HHMI research resulted in VirScan, an alternative to medical laboratory tests that test for specific viruses one at a time, and which can detect all diseases a patient has had over his or her lifetime, according to an HHMI news statement about the new technology. (more…)
