Developing new biomarkers for liver cancer with RNA splicing techniques

Researchers at Cold Spring Harbor Laboratory (CSHL), led by Professor Adrian Krainer, have developed a method for identifying splicing-based biomarkers for hepatocellular carcinoma (HCC). They have published their findings in journal Genome Research.

Different versions, or isoforms, of messenger RNAs generated by the human AFMID gene, are represented, showing their relative prevalence in cancerous (top) and non-cancerous tissue (bottom), sampled from throughout the body. Black peaks, representing the normal variant found in adult cells, are much lower in cancerous tissue than in normal tissue. The reverse is true of variants color-coded orange and red, which serve as biomarkers in liver cancer. Credit: Krainer Lab, CSHL

“This study underscores the potential for learning how RNA splicing variants can contribute to cancer and points to these variants as potential biomarkers for cancer progression,” Krainer says.

Splicing refers to a process in which an RNA message copied from information encoded in a gene is edited before it can serve as a blueprint for the manufacture of a specific protein. A gene can give rise to multiple RNA messages, each resulting in a different protein variant, or “isoform.” Variation and errors in RNA splicing cause the production of nonfunctional proteins or proteins with aberrant function, and it is associated with many diseases.

Recent studies have identified splicing irregularities in liver cancer cells. Led by Cold Spring Harbor Laboratory postdoctoral researcher Kuan-Ting Lin, Krainer’s team developed a method that comprehensively analyzes all RNA messages made from a given gene. The team tested their splicing-variant detection method in HCC, by examining RNA messages in hepatocellular carcinoma cells sampled from hundreds of patients.

Researchers found that specific splicing isoforms of gene AFMID is associated poor survival.  These variant isoforms lead cells to manufacture truncated versions of the AFMID protein. These unusual versions of the protein are associated with adult liver cancer cells with mutations in tumor-suppressor genes called TP53 and ARID1A.

Researchers hypothesize that these mutations are associated with low levels of a molecule called NAD+ that is involved in repairing damaged DNA. Restoring missing portions, called exons, to AFMID’s usual RNA message, they propose, might raise NAD+ to normal levels, avoiding mutations in TP53 and ARID1A. The team hopes to use small molecules called antisense oligonucleotides (ASOs) that can bind to RNA, to change the way AFMID’s RNA messages are spliced. Krainer’s team previously used this technique to correct errors in the splicing of the gene SMN2 as a way to treat spinal muscular atrophy (SMA).

Citation: Lin, Kuan-Ting, Wai Kit Ma, Juergen Scharner, Yun-Ru Liu, and Adrian R. Krainer. “A human-specific switch of alternatively splicedAFMIDisoforms contributes toTP53mutations and tumor recurrence in hepatocellular carcinoma.” Genome Research 28, no. 3 (2018): 275-84. doi:10.1101/gr.227181.117.

Research funding: National Institutes of Health

Adapted from press release by Cold Spring Harbor Laboratory (CSHL).

Animal study finds MeXis gene protective against coronary artery disease

UCLA scientists have identified a gene called MeXis that may play a protective role in preventing heart disease. Their findings suggests that this gene acts within macrophages inside clogged arteries to help remove excess cholesterol from blood vessels by controlling cholesterol pump protein expression. Research is published in the journal Nature Medicine.

MeXis is an example of a “selfish” gene, one that is presumed to have no function because it does not make a protein product. However, recent studies have suggested that these so-called “unhelpful” genes can actually perform important biological functions without making proteins and instead producing a special class of molecules called long non-coding RNAs, or lncRNAs.

“What this study tells us is that lncRNAs are important for the inner workings of cells involved in the development of heart disease,” said Dr. Peter Tontonoz, senior author of the study. “Considering many genes like MeXis have completely unknown functions, our study suggests that further exploring how other long non-coding RNAs act will lead to exciting insights into both normal physiology and disease.”

In the study, researchers found that mice lacking MeXis had almost twice as many blockages in their blood vessels compared to mice with normal MeXis levels. In addition, boosting MeXis levels made cells more effective at removing excess cholesterol. In the next phase of the study, researchers will further explore how MeXis affects the function of cells in the artery wall and will test various approaches to altering MeXis activity. The researchers are interested in finding out if MeXis could be targeted for therapy of cardiovascular disease.

Citation: Sallam, Tamer, Marius Jones, Brandon J. Thomas, Xiaohui Wu, Thomas Gilliland, Kevin Qian, Ascia Eskin, David Casero, Zhengyi Zhang, Jaspreet Sandhu, David Salisbury, Prashant Rajbhandari, Mete Civelek, Cynthia Hong, Ayaka Ito, Xin Liu, Bence Daniel, Aldons J. Lusis, Julian Whitelegge, Laszlo Nagy, Antonio Castrillo, Stephen Smale, and Peter Tontonoz. “Transcriptional regulation of macrophage cholesterol efflux and atherogenesis by a long noncoding RNA.” Nature Medicine, 2018. doi:10.1038/nm.4479.

Funding: NIH/National Heart, Lung and Blood Institute, Burroughs Wellcome Fund Career Awards for Medical Scientists, UCLA Cardiovascular Discovery Fund, Lauren B. Leichtman and Arthur E. Levine Investigator Award.

Adapted from press release by the University of California Los Angles Health Sciences.

New approach to treating dementia using antisense oligonucleotides

In a study of mice and monkeys, NIH funded researchers showed that they could prevent and reverse some of the brain injury caused by the toxic form of a protein called tau.

Scientists used a designer compound to prevent and reverse brain damage caused by tau in mice.
Credit: Miller lab, Washington University, St. Louis, MO

The results, published in Science Translational Medicine, suggest that the study of compounds, called tau antisense oligonucleotides, that are genetically engineered to block a cell’s assembly line production of tau, might be pursued as an effective treatment for a variety of disorders. Antisense oligonucleotides are short sequences of DNA or RNA that are programmed to turn genes on or off.

In several disorders, toxic forms of tau clump together inside dying brain cells and form neurofibrillary tangles, including Alzheimer’s disease, tau-associated frontotemporal dementia, chronic traumatic encephalopathy and progressive supranuclear palsy.

Researchers tested sequences designed to turn tau genes off in mice that are genetically engineered to produce abnormally high levels of a mutant form of the human protein. Tau clusters begin to appear in the brains of 6-month-old mice and accumulate with age. The mice develop neurologic problems and die earlier than control mice.

Injections of the tau antisense oligonucleotides into the fluid-filled spaces of the mice brains prevented tau clustering in 6-9-month-old mice and appeared to reverse clustering in older mice. The compound prevented the older mice from losing their ability to build nests. Further experiments on non-human primates suggested that the antisense oligonucleotides tested in mice could reach important areas of larger brains and turn off tau. In comparison with placebo, two spinal tap injections of the compound appeared to reduce tau protein levels in the brains and spinal cords of Cynomologus monkeys. As the researchers saw with the mice, injections of the compound caused almost no side effects.

Currently, researchers are conducting early phase clinical trials on the safety and effectiveness of antisense oligonucleotides designed to treat several neurological disorders, including Huntington’s disease and amyotrophic lateral sclerosis. The U.S. Food and Drug Administration recently approved the use of an antisense oligonucleotide for the treatment of spinal muscular atrophy, a hereditary disorder that weakens the muscles of infants and children.

Citation: DeVos, Sarah L., Rebecca L. Miller, Kathleen M. Schoch, Brandon B. Holmes, Carey S. Kebodeaux, Amy J. Wegener, Guo Chen et al. “Tau reduction prevents neuronal loss and reverses pathological tau deposition and seeding in mice with tauopathy.” Science Translational Medicine 9, no. 374 (2017): eaag0481.
DOI: 10.1126/scitranslmed.aag0481
Research funding: National Institutes of Health, Tau Consortium, Cure PSP.
Adapted from press release by National Institute of Neurological Disorders and Stroke.

New approach to treating Obesity with fat burning molecule ABX300

A small molecule ABX300 could provide valuable help in combating the global epidemic of obesity. When it was fed to obese mice, the animals’ metabolism sped up and their excess weight was shed. It is doing so by recruiting the help of a body’s own genes in countering the effects of a high-fat diet. The research team conducting the study believes their findings may provide a new unexplored therapeutic approach to fighting excessive weight gain in cases where diets or exercise have no effect. The study was led by Julien Santo, Celia Lopez-Herrera and Cécile Apolit of a French biotechnology company, and is published in Springer Nature’s International Journal of Obesity.

A high-fat diet may contribute to obesity in some individuals. Treatment in such situations has focused on behavioral changes, which is highly challenging to achieve for the general population on a long term basis. This study introduces the concept of recruiting the help of our genes in countering the effects of a high-fat diet, instead of focusing on reducing the intake of high-fat food.
Researchers know that the structure of some genes that help to produce certain proteins can actually change when someone constantly eats too much high-fat food. In the process, the person can become overweight or obese, or develop other lifestyle-related metabolic disorders such as diabetes or heart problems. In many cases, the same gene can produce two or more alternate proteins, based on how the translation from DNA (gene) to proteins is processed. One of these genes is LMNA, which plays a role in the development of different metabolic disorders. The LMNA RNA, which is the genetic material resulting from a process called DNA transcription, is modified by three SR proteins called SRSFI, SRSF5, and SRSF6. In this process called splicing, the genetic material encoded in the RNA is basically diced or shifted around and therefore alters the resulting proteins.

The research team found that a small molecule ABX300 is able to change the way one particular SR protein, SRSFI, works in the bodies of mice that gained excessive weight after being fed a high-fat diet. SRSFI determines which of the gene products of opposing effects could be produced from a single LMNA gene. One gene product promotes fat storage, the other opposes it. This study showed that blocking SRSFI with a compound promotes gene expression of the protein that burns calories and prevents fat gain or induces fat loss when mice are on a high-fat diet. It did not have any effect on lean mice of normal weight.

According to the research team, this approach alters the animals’ metabolic rate or energy expenditure. It means that it can speed up the metabolism of obese animals and that their bodies start to function at a higher energy level shedding the excess weight. In the process, their bodies started to burn much more fat, as especially fatty acids serve as much-needed sources of energy.

“The results of this animal study show that this molecule can abrogate or do away with the effect of a high-fat diet,” says Santo.

“Dietary management and exercise are not always successful as an intervention for obesity, underscoring the need for efficient medication to treat metabolic disorders,” adds Lopez-Herrera, who believes that this treatment represents an as yet unexplored approach to treating obesity.

According to Apolit, this compound did not seem to have any adverse effects, so more research in animals and eventual research in humans is needed. If the studies are positive, this may be a new way to treat obesity.

Citation: Santo J, Lopez-Herrera C, Apolit C, Bareche Y, Lapasset L, et. al. “Pharmacological modulation of LMNA SRSF1-dependent splicing abrogates diet-induced obesity in mice”. International Journal of Obesity 2016.
DOI: 10.1038/ijo.2016.220
Adapted from press release by Springer.

Research shows meninges contain neural progenitor stem cells

In a cross-domain study directed by professor Peter Carmeliet, researchers discovered unexpected cells in the protective membranes that enclose the brain, the so-called meninges. These ‘neural progenitors’ – or stem cells that differentiate into different kinds of neurons – are produced during embryonic development. These findings show that the neural progenitors found in the meninges produce new neurons after birth – highlighting the importance of meningeal tissue as well as these cells’ potential in the development of new therapies for brain damage or neurodegeneration. A paper highlighting the results was published in the leading scientific journal Cell Stem Cell.

Before the discoveries of the last few decades, neurologists once thought that the brain became ‘static’ after childhood. This dogma has changed, with researchers finding more and more evidence that the brain is capable of healing and regenerating in adulthood, thanks to the presence of stem cells. However, neuronal stem cells were generally believed to only reside within the brain tissue, not in the membranes surrounding it.

Believed in the past to serve a mainly protective function to dampen mechanical shocks, the meninges have been historically underappreciated by science as having neurological importance in its own right. The data gathered by the team challenges the current idea that neural precursors – or stem cells that give rise to neurons – can only be found inside actual brain tissue.

Prof. Peter Carmeliet said “The neuronal stems cells that we discovered inside the meninges differentiate to full neurons, electrically-active and functionally integrated into the neuronal circuit. To show that the stem cells reside in the meninges, we used the extremely powerful single-cell RNA sequencing technique, a very novel top-notch technique, capable of identifying the (complex gene expression signature) nature of individual cells in a previously unsurpassed manner, a première at VIB.”

 When it comes to future leads for this discovery, the scientists also see possibilities for translation into clinical application, though future work is required. Prof. Peter Carmeliet said “An intriguing question is whether these neuronal stem cells in the meninges could lead to better therapies for brain damage or neurodegeneration. However, answering this question would require a better understanding of the molecular mechanisms that regulate the differentiation of these stem cells. How are these meningeal stem cells activated to become different kinds of neurons? Can we therapeutically ‘hijack’ their regeneration potential to restore dying neurons in, for example, Alzheimer’ Disease, Parkinson’s Disease, amyotrophic lateral sclerosis (ALS), and other neurodegenerative disorders? Also, can we isolate these neurogenic progenitors from the meninges at birth and use them for later transplantation? These findings open up very exciting research opportunities for the future.”

 Moving into unchartered territory is high risk, and can offer high gain, but securing funding for such type of research is challenging. However, Carmeliet’s discoveries were made possible to a large extent by funding through “Opening the Future: pioneering without boundaries”, a recently created Mecenas Funding Campaign for funding of high-risk brain research but with potential for breakthrough discoveries, started up by the KU Leuven in 2013 and unique in Flanders.

Citation: “Neurogenic Radial Glia-like Cells in Meninges Migrate and Differentiate into Functionally Integrated Neurons in the Neonatal Cortex”. Francesco Bifari1, Ilaria Decimo1, Annachiara Pino, Enric Llorens-Bobadilla, Sheng Zhao, Christian Lange, Gabriella Panuccio, Bram Boeckx, Bernard Thienpont, Stefan Vinckier, Sabine Wyns, Ann Bouché, Diether Lambrechts, Michele Giugliano, Mieke Dewerchin, Ana Martin-Villalba, Peter Carmeliet. Cell Stem Cell 2016.
Research funding: Mecenas funding initiative by the KU Leuven
Adapted from press release by VIB Vlaams Instituut Voor Biotechnologie (The Flaunders institute of biotechnology)

Research finds role of Messenger RNA in Huntington’s disease patholgy

A research effort at the Centre for Genomic Regulation in Barcelona, Spain, reveals new molecular mechanisms of Huntington’s disease. The results, published in The Journal of Clinical Investigation, question the approaches used up to now for treatment of the disease. They also point to messenger RNA as a key pathogenic component that will make it possible to define new therapeutic strategies.

Fluorescent detection of foci in red fibroblasts of patients with
Huntington’s disease. Up: cells showing mutated RNA foci.
Down: Cells with blocked RNA do not show foci.
Credit: Centre for Genoic Regulation

Huntington’s disease is a neurodegenerative disease that is presently incurable. Scientists around the world are researching its causes and molecular processes in the attempt to find a treatment. Huntington’s disease is caused by the excessive repetition of a nucleotide triplet (CAG) in the Huntingtin gene. The number of CAG repetitions varies from person to person. Healthy individuals can have up to 36 repetitions. Nevertheless, as of 36 repetitions, Huntington’s disease develops. The direct consequence of this excess of repetitions is the synthesis of a mutated protein–different from what would be obtained without the additional CAG repetitions–which has been considered the main cause of the disease for the past 20 years.

The research by a group of scientists from the Centre for Genomic Regulation (CRG) led by Eulàlia Martí, in cooperation with researchers from the University of Barcelona (UB) and August Pi i Sunyer Biomedical Research Institute (IDIBAPS), has brought to light new information on the molecular mechanisms that cause Huntington’s disease, and defines new pathways to therapy discovery.

What we have observed in our study is that the mutated fragment acting as a conveyor–the so-called messenger RNA–is key in the pathogenesis,” says Dr. Eulàlia Martí, lead author of the research project, together with Xavier Estivill, and acting group leader of the Genes and Disease laboratory at the Centre for Genomic Regulation. “The research on this disease being done by most groups around the world seeking new therapeutic strategies focuses on trying to prevent expression of the mutated protein. Our work suggests that blocking the activity of messenger RNA (the “conveyor”), would be enough to revert the alterations associated with Huntington’s disease. We hope this will contribute to improving the strategies in place to find a cure,” states the researcher.

Going deeper in molecular mechanisms enables progress to future applications. This work underscores the importance of rethinking the mechanisms behind illnesses in order to find new treatments. The work of scientists at the CRG has helped explore the molecular mechanisms that cause the disease. Now, their results will contribute to better delimit research efforts towards a cure.

As opposed to most other research groups, Eulàlia Martí’s team has sought to identify whether the problem resided in the messenger RNA – which would be the copy responsible for manufacturing the protein – or in the resulting protein. Prior work indicated that mRNA produced, in addition to defective protein, other damages. This previous work was the starting point for Martí and her fellow researchers, who have finally demonstrated that mRNA has a key role in the pathogenesis of Huntington’s chorea. “The research we have just published points to RNA’s clear role in Huntington’s disease. This information is very important in translational research to take on new treatments,” says the researcher.

More in-depth studies on these mechanisms are yet to be done. For example, research must explore whether it will be possible to revert the effects of Huntington’s disease in patients, just as researchers have demonstrated in mouse models. It also remains to be seen whether the proposal of the CRG researchers can be used in a preventive way, as the disease does not generally appear until after 40 years of age (in humans). Despite the remaining gaps, the published work makes for a key step in knowledge of the mechanisms of this neurodegenerative disease that, as of today, remains incurable.

Citation: Rué, Laura, Mónica Bañez-Coronel, Jordi Creus-Muncunill, Albert Giralt, Rafael Alcalá-Vida, Gartze Mentxaka, Birgit Kagerbauer et al. “Targeting CAG repeat RNAs reduces Huntington’s disease phenotype independently of huntingtin levels.” The Journal of Clinical Investigation 126, no. 11 (2016).
Adapted from press release by Centre for Genomic Regulation

New method to study RNA G-quadruplexes to understand their role in cancer

An international research team led by the University of Leicester has made a breakthrough advance in understanding about RNA that could pave a new route for the development of anti-cancer drugs. This research is published in Nature Chemical Biology.

Professor Ian Eperon and Dr Cyril Dominguez from the University of Leicester’s Institute of Structural and Chemical Biology led the team that developed a new method to analyse the RNA step in expressing our genetic code. Dr Dominguez, of the Department of Molecular and Cell Biology, said: “Our research aims at understanding how four-stranded RNA structures called G-quadruplexes affect cellular processes such as RNA splicing. In this research, we describe a novel method that, for the first time, allows us to show that G-quadruplexes form in long RNAs and in conditions where the splicing reaction can take place.”

G-quadruplexes are specific structures formed when a piece of DNA or RNA folds into a four-stranded structure. DNA G-quadruplexes have been shown to be associated with diseases such as cancer and many small molecules called G-quadruplex binders have been developed as putative novel anti-cancer drugs, the best example being Quarfloxin that reached a phase II clinical trial. RNA G-quadruplexes are also believed to play important roles in cancers but to date there are no straightforward methods to prove that they exist in cells. If they form and do control RNA splicing, then the design of molecules that bind them would be a new route for the development of anti-cancer drugs.

During the process of gene expression, DNA is transcribed to RNA molecules that are in turn translated to produce proteins. RNA splicing is an essential step in producing the finished messenger RNA and the RNA copied from one gene can be spliced in different ways. This is how the 20,000 human genes can produce around 130,000 proteins.

This process is highly regulated and defects in its regulation are a common cause of many diseases, including spinal muscular atrophy and some cancers.

Professor Eperon said: “Our novel method, footprinting of long 7-deazaguanine-substituted RNAs (FOLDeR), will allow RNA scientists to investigate the existence of G-quadruplexes in physiological condition allowing a better understanding of their role in cellular processes. It is particularly interesting that the RNA we have been studying is one that plays an important role in some cancers. When the RNA is spliced using one set of sites, it produces a protein favouring cell survival. This is a problem for cancer treatments, many of which work by damaging growing cells in the hope that they will then die. However, when an alternative set of sites is used, the RNA produces a protein that encourages cell death. We have shown that G-quadruplexes form near the alternative sites, and our hope is that we can target these to shift splicing towards the pro-death pattern.”

This is a major step forward in the G-quadruplex research field. In a follow-up paper, the team will report their work on drugs that exploit this structure.

Citation: Carika Weldon, Isabelle Behm-Ansmant, Laurence H Hurley, Glenn A Burley, Christiane Branlant, Ian C Eperon & Cyril Dominguez. “Identification of G-quadruplexes in long functional RNAs using 7-deazaguanine RNA” Nature Chemical Biology (2016).
Research funding: MRC Career Development Award, Bank of Butterfield Foundation
Adapted from press release by University of Leicester

New approach to treating cancer with therapeutic short interfering RNA (siRNA) delivered by nanohydrogel nanoparticles

A novel targeted therapy using nanoparticles has enabled researchers at the Georgia Institute of Technology to purge ovarian tumors in limited, in vivo tests in mice. “The dramatic effect we see is the massive reduction or complete eradication of the tumor, when the ‘nanohydrogel’ treatment is given in combination with existing chemotherapy,” said chief researcher John McDonald.

That nanohydrogel is a minute gel pellet that honed in on malignant cells with a payload of an RNA strand. The RNA entered the cell, where it knocked down a protein gone awry that is involved in many forms of cancer.

In trials on mice, it put the brakes on ovarian cancer growth and broke down resistance to chemotherapy. That allowed a common chemotherapy drug, cisplatin, to drastically reduce or eliminate large carcinomas with very similar speed and manner. The successful results in treatment of four mice with the combination of siRNA and cisplatin showed little variance.

The therapeutic short interfering RNA (siRNA) developed by McDonald and Georgia Tech researchers Minati Satpathy and Roman Mezencev, thwarted cancer-causing overproduction of cell structures called epidermal growth factor receptors (EGFRs), which extend out of the wall of certain cell types. EGFR overproduction is associated with aggressive cancers. The nanohydrogel that delivers the siRNA to the cancer cells is a colloid ball of a common, compact organic molecule and about 98 percent water. Another molecule is added to the surface of the nanohydrogel as a guide. In the in vivo trials, the siRNA, which contained a fluorescent tag, allowed researchers to observe nanoparticles successfully honing in on the cancer cells.

The researchers from Georgia Tech’s School of Biological Sciences published their results on Monday, November 7, 2016, in the journal Scientific Reports.

The new treatment has not been tested on humans, and research would be required by science and by law to demonstrate consistent results – efficacy – among other things, before preliminary human trials could become possible.

Citation: Minati Satpathy, Roman Mezencev, Lijuan Wang & John F. McDonald. “Targeted in vivo delivery of EGFR siRNA inhibits ovarian cancer growth and enhances drug sensitivity”
Scientific Reports 6, Article number: 36518 (2016)
Research funding: National Institutes of Health’s IMAT Program, Ovarian Cancer Institute, Deborah Nash Endowment Fund, Curci Foundation and Markel Foundation.
Adapted from press release by Georgia Institute of Technology

Researchers map short RNA molecules in single cell

Researchers at Karolinska Institutet have measured the absolute numbers of short, non-coding, RNA sequences in individual embryonic stem cells. The new method could improve the understanding of how our genes are regulated and different cell types develop.

When information in our genes is used, for example to build a protein, it is first translated to messenger-RNA which functions as a blueprint for the protein. Our cells also contain non-coding, short, RNA sequences that do not contribute to the formation of proteins and whose functions are partly unknown. The best known of these is micro RNA (miRNAs), which can interact with the messenger RNA, and thereby regulate genes and cell function.

Researchers at Karolinska Institutet have now mapped the presence of short RNA-sequences in an individual cell. Previous research on short RNA molecules is based on analysis of many cells simultaneously, making it difficult to study the precise function.

“Our knowledge of the function of short RNA molecules is quite general. We have a picture of the general mechanisms, but it is less clear what specific role these molecules play in different types of cells or diseases,” says Rickard Sandberg, professor at the Department of Cell and Molecular Biology, who is also affiliated to the Stockholm center of Ludwig Cancer Research.

The analysis was done using single-cell transcriptomics, a technique which makes it possible to measure the absolute numbers of short RNA molecules in a cell. Two types of embryonic stem cells were used, intended to mimic the early embryo, before and after it has attached to the uterine lining.

The researchers could detect large numbers of small RNAs in both cell states, including miRNA as well as shorter RNA fragments (tRNA and snoRNA) whose function is largely unknown. The researchers also found that large numbers of miRNAs are expressed differently in the two cell states.

“This is basic research and a demonstration that the method works, giving suggestions for further research. To map the levels of short RNA molecules in a cell is a first step in identifying the specific function of these molecules,” says Omid Faridani, one of the lead authors of the study. In the long run, Rickard Sandberg can imagine clinical applications of the method.

Citation: Faridani, Omid R., Ilgar Abdullayev, Michael Hagemann-Jensen, John P. Schell, Fredrik Lanner, and Rickard Sandberg. “Single-cell sequencing of the small-RNA transcriptome.” Nature Biotechnology (2016).
Adapted from press release by Karolinska Institutet