Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Disease knowledge may advance faster with CRISPR gene probing tool

New technology can turn off genes more precisely, UCSF researchers say

Scientists at UC San Francisco have found a more precise way to turn off genes, a finding that will speed research discoveries and biotech advances and may eventually prove useful in reprogramming cells to regenerate organs and tissues.

The strategy borrows from the molecular toolbox of bacteria, using a protein employed by microbes to fight off viruses, according to the researchers, who describe the technique in the current issue of Cell.

Turning off genes is a major goal of treatments that target cancer and other diseases. In addition, the ability to turn genes off to learn more about how cells work is a key to unlocking the mysteries of biochemical pathways and interactions that drive normal development as well as disease progression.

"We've spent energy and effort to map the human genome, but we don't yet understand how the genetic blueprint leads to a human being, and how we can manipulate the genome to better understand and treat disease," said Wendell Lim, PhD, a senior author of the study. Lim is director of the UCSF Center for Systems and Synthetic Biology, a Howard Hughes Medical Investigator and professor of cellular and molecular pharmacology.

The new technology developed by the team of UCSF and UC Berkeley researchers is called CRISPR interference – not to be confused with RNA interference, an already popular strategy for turning off protein production.

"CRISPR interference is a simple approach for selectively perturbing gene expression on a genome-wide scale," said Lei Stanley Qi, PhD, a UCSF Systems Biology Fellow who was the lead author of the Cell study. "This technology is an elegant way to search for any short DNA sequence in the genome, and to then control the expression of the gene where that sequence is located."

The technique will allow researchers to more easily and accurately trace patterns of gene activation and biochemical chains of events that take place within cells, Qi said, and will help scientists identify key proteins that normally control these events and that may go awry in disease.

Unlike conventional RNA interference techniques, CRISPR interference allows any number of individual genes to be silenced at the same time, Qi said. In addition, it acts more crisply, if you will, by not turning off untargeted genes the way RNA interference techniques do.

Gene switching by RNA interference was identified more than a decade ago, launching a new research field that has spawned a Nobel Prize and billion-dollar biotech firms. In January, the U.S. Food and Drug Administration announced its first approval of an injectable disease therapy based on a similar interference strategy, a drug to treat a rare form of high cholesterol.

RNA interference blocks the messenger RNA that drives protein protection based on the blueprint contained within a gene's DNA sequence. By preventing protein production, RNA interference may be used to get around the problem of difficult-to-target proteins, a frequent challenge in drug development.

But CRISPR interference acts one step earlier in the cell's protein manufacturing process. "The horse has already left the barn with RNA interference, in the sense that the RNA message already has been transcribed from DNA," said Jonathan Weissman, PhD, a Howard Hughes Medical Investigator and professor of cellular and molecular pharmacology, who is another senior author on the work. "With CRISPR interference, we can prevent the message from being written."

CRISPR – an acronym for "clustered regularly interspaced short palindromic repeats" – is a system that bacteria use to defend themselves against viruses. CRISPR acts like a vaccine, incorporating bits of genes from viruses. Bacteria can reference this library of virus genes to recognize and attack viral invaders.

Qi and colleagues used a protein from this system, called Cas9, as a chassis into which they can insert any specific RNA partner molecule. The selected RNA serves as an adaptor that determines the target anywhere within the genome. "Targeting the machinery to new sites is extremely flexible and quick," Qi said.

The research team was able to get the system to work in mammalian cells as well as bacterial cells, and is working to improve its efficiency in mammalian cells, including human cells. The team aims to couple the Cas9 chassis to an enzyme that will enable the technology to turn genes on as well as off.

Such a versatile tool could prove valuable in efforts to reprogram cells for regenerative medicine. Lim's own lab is working on reprogramming immune cells to treat cancer.

"The idea is to reprogram cells to do the things we want them to do," Lim said. "We are still unlocking the secrets of the genome to harness the power of cellular reprogramming."

Additional UCSF co-authors of the February 28 Cell study are postdoctoral fellows Matthew Larson, PhD, and Luke Gilbert, PhD. UC Berkeley co-authors are Adam Arkin, PhD, professor of bioengineering; and Jennifer Doudna, PhD, Howard Hughes Medical Investigator and professor of biochemistry. All the study authors are members of QB3, the California Institute for Quantitative Biosciences.

The research was funded by the National Institutes of Health, the Howard Hughes Medical Institute and the National Science Foundation.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.

Jeffrey Norris | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Molecular doorstop could be key to new tuberculosis drugs
20.03.2018 | Rockefeller University

nachricht Modified biomaterials self-assemble on temperature cues
20.03.2018 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Scientists invented method of catching bacteria with 'photonic hook'

20.03.2018 | Physics and Astronomy

Next Generation Cryptography

20.03.2018 | Information Technology

Science & Research
Overview of more VideoLinks >>>