Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cancer-associated long non-coding RNA regulates pre-mRNA splicing

24.09.2010
Researchers report this month that MALAT1, a long non-coding RNA that is implicated in certain cancers, regulates pre-mRNA splicing – a critical step in the earliest stage of protein production. Their study appears in the journal Molecular Cell.

Nearly 5 percent of the human genome codes for proteins, and scientists are only beginning to understand the role of the rest of the "non-coding" genome. Among the least studied non-coding genes – which are transcribed from DNA to RNA but generally are not translated into proteins – are the long non-coding RNAs (lncRNAs).

Before the human genome was fully sequenced, it was a "protein-centric world," said University of Illinois cell and developmental biology professor Kannanganattu Prasanth, who led the study. With the sequencing of the genome it became clear, however, that a majority of genes code for RNAs that are not translated into proteins.

In recent years, research on non-coding RNAs has blossomed, but most studies have focused only on small non-coding RNAs, which play critical roles in several aspects of cellular function. There have been comparatively fewer studies on lncRNAs, Prasanth said. As a result, researchers are only beginning to understand the functions of a few lncRNAs.

Prasanth's laboratory focuses on understanding the role of lncRNAs, such as MALAT1, which normally are distributed in the nucleus of mammalian cells.

Preliminary studies suggest that lncRNAs carry out vital regulatory functions in cells. When those functions go awry, Prasanth said, serious consequences can result. Abnormal expression of the MALAT1 gene, for example, is implicated in many cancers, including breast, lung and liver cancers, "so the scientific world was interested in what this RNA could be doing in normal cells, and how changes in its expression correlate with cancer," he said.

Prasanth was also the co-first-author of another study, recently published in The EMBO Journal, that found that MALAT1 plays a role in recruiting important proteins, called pre-mRNA splicing factors, to the site of gene transcription in the nucleus.

Pre-mRNA splicing involves cutting out unneeded sequences and piecing the mRNAs together before they are exported from the nucleus and translated into proteins.

"That study gave us the clue that MALAT1 is an important gene that might be involved in pre-mRNA metabolism," Prasanth said.

In the new study, Prasanth and his colleagues tested the hypothesis that MALAT1 interacts with and modulates the behavior of a group of pre-mRNA splicing factors known as the SR-family splicing factors.

The researchers found that the MALAT1 sequence contains multiple regions that can bind SR-splicing proteins. Further experiments showed that MALAT1 does indeed bind to several members of the SR-proteins the team analyzed.

Furthermore, depleting cells of MALAT1 or over-expressing the splicing factors to which it can bind led to the same alteration in the splicing of a large number of pre-mRNAs in the cells, suggesting that MALAT1 latches onto the splicing factors and regulates their access to new transcripts.

"All of the data strongly suggest that MALAT1 is acting as a regulator of splicing by modulating the levels of the splicing factors in the cell," Prasanth said.

This study verifies that MALAT1 plays a key role in pre-mRNA processing, with broad implications for human health, Prasanth said.

"Numerous studies have shown that aberrant splicing of pre-mRNA is a major issue associated with several diseases, including cancer," he said. "Some of the factors we know interact with MALAT1 have been shown to be oncogenes. If you over-express these genes you can make a cell cancerous."

"Similarly, some of the genes whose pre-mRNA splicing is controlled by MALAT1 are members of the cancer 'signature genes,' " Prasanth said. "This means that their abnormal expression is directly correlated with several cancers."

Post-doctoral researcher Vidisha Tripathi led this work, with assistance from undergraduate student David Song. Supriya Prasanth, a professor of cell and developmental biology at Illinois, and her graduate student, Zhen Shen, also contributed to the study. The research team also included scientists from the University of Toronto; ISIS Pharmaceuticals, Carlsbad, Calif.; and Wright State University, Dayton, Ohio.

Editor's notes: To reach Kannanganattu Prasanth, e-mail
kumarp@illinois.edu

Diana Yates | EurekAlert!
Further information:
http://www.illinois.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>