Tumor chromosomal translocations reproduced for the first time in human cells

The research has been made possible thanks to the use of new molecular tool for the manipulation of the cellular genome

2014-06-03

(Press-News.org) Scientists from the Spanish National Cancer Research Centre (CNIO) and the Spanish National Cardiovascular Research Centre (CNIC) have been able to reproduce, for the first time in human cells, chromosomal translocations associated with two types of cancer: acute myeloid leukaemia and Ewing's sarcoma. The discovery, published today in the journal Nature Communications, opens the door to the development of new therapeutic targets to fight these types of cancer.

The study was carried out by Sandra Rodriguez-Perales − from CNIO's Molecular Cytogenetics Group, led by Juan Cruz Cigudosa − and Juan Carlos Ramírez and Raúl Torres, from CNIC's Viral Vector Technical Unit. The researchers have shown that it is possible to produce chromosome modifications in human cells that are genetically identical to those observed in leukaemia and other types of human cancer.

This new technology offers two main advantages based on the use of molecular tools to manipulate the genome: firstly, working models that had not existed up until now for the study of tumour biology and, secondly, their application will eventually allow for the study of new therapeutic targets and therapies.

The alterations leading to tumour development are due to multiple changes in cell physiology and specifically in the cell genome. In leukaemia and other tumours called sarcomas, exchanges of large DNA fragments occur between different chromosomes, a phenomenon known as chromosomal translocations. As the study's authors point out, these translocations are necessary both for the generation and the progression of a number of neoplastic processes.

"The study of this type of tumours has been problematic up to now due to the lack of cell models and the appropriate animal models", says CNIC researcher Juan Carlos Ramírez, who adds that the difficulty of generating these chromosomal translocations had limited the availability of cells with this mark of the disease.

Breaking chromosomes to study cancer

Using RNA-Guided Endonuclease (RGEN) technology or CRISPR/Cas9 genome engineering technology, CNIO and CNIC researchers have shown that it is possible to obtain such chromosomal translocations. In this way, they have managed to reproduce chromosomal translocations in human stem cells from blood and mesenchymal tissue that are identical to those observed in patients with acute myeloid leukemia (a blood and bone marrow cancer) or Ewing's sarcoma (a type of bone tumour that affects children and teenagers).

"With this breakthrough it is possible to generate cell models with the same alterations as observed in tumour cells from patients, which will allow us to study their role in tumour development", says CNIO researcher Sandra Rodríguez-Perales. "In this way, it will be possible to experimentally recapitulate the necessary subsequent steps for normal cells to transform into cancer cells".

The researchers have used the powerful RGEN tool, which was developed at the beginning of 2013, for gene manipulation in eukaryotic cells, including human ones. It is based on the design of a small RNA (RNAsg) that is complementary and specific to a 20 nucleotide DNA region. The binding of the RNAsg to the DNA acts as a signal for the Cas9 enzyme to produce a cut on the edge of the marked DNA. The system is very specific and efficient and allows for cuts to be made in the DNA's double helix wherever the researchers need to do so.

Rodríguez-Perales, Torres and Ramírez have shown that by transferring the RGEN components into primary human cells, regions of the exchanged chromosomes in some tumours can be marked, thus generating cuts in those chromosomes.

"When the DNA repair machinery tries to repair those cuts, it drives the generation of a translocation between two different chromosomes, in many cases reciprocally between the two chromosomes implicated", says CNIC researcher Raúl Torres.

The study's authors conclude by stating that the use of this technology will also allow for the clarification of how and why chromosomal translocation occurs, which without doubt will allow new anti-cancer therapeutic strategies to be tackled.

INFORMATION:

Reference article: Engineering human tumor associated chromosomal translocations with the RNA-guided CRISPR-Cas9 system. Raúl Torres, Maria C. Martin, Aida Garcia, Juan C. Cigudosa, Juan C. Ramirez, Sandra Rodriguez-Perales. Nature Communications (2014). doi: 10.1038/ncomms4964

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Children with autism have elevated levels of steroid hormones in the womb

2014-06-03

Scientists from the University of Cambridge and the Statens Serum Institute in Copenhagen, Denmark have discovered that children who later develop autism are exposed to elevated levels of steroid hormones (for example testosterone, progesterone and cortisol) in the womb. The finding may help explain why autism is more common in males than females, but should not be used to screen for the condition. Funded by the Medical Research Council (MRC), the results are published today in the journal Molecular Psychiatry. The team, led by Professor Simon Baron-Cohen and Dr ...

Reduced neurosurgical resident hours: No significant positive effect on patient outcomes

2014-06-03

Charlottesville, VA (June 3, 2014). In July 2003 the Accreditation Council for Graduate Medical Education (ACGME) imposed a mandatory maximum 80-hour work-week restriction on medical residents. Before that time residents often worked in excess of 100 hours per week. To investigate whether positive changes in patient outcomes occurred following implementation of the ACGME mandate, four researchers from Minnesota—Kiersten Norby, M.D., Farhan Siddiq, M.D., Malik M. Adil, M.D., and Stephen J. Haines, M.D.—analyzed hospital-based data from three years before (2000-2002) and ...

Survey finds 'significant gap' in detection of malnutrition in Canadian hospital patients

2014-06-03

A new survey of Canadian physicians shows a "significant gap" between optimal practices to detect nutrition problems in hospitalized patients and what action is actually taking place. The survey, conducted by the Canadian Malnutrition Task Force, looked at physician attitudes and perceptions about identifying and treating nutrition issues among hospitalized patients. The startling findings of the survey were published today in the OnlineFirst version of the Journal of Parenteral and External Nutrition (JPEN), the research journal of the American Society for Parenteral ...

Bacterium causing US catfish deaths has Asian roots

2014-06-03

A bacterium causing an epidemic among catfish farms in the southeastern United States is closely related to organisms found in diseased grass carp in China, according to researchers at Auburn University in Alabama and three other institutions. The study, published this week in mBio®, the online open-access journal of the American Society for Microbiology, suggests that the virulent U.S. fish epidemic emerged from an Asian source. Since 2009, catfish farming in Alabama, Mississippi and Arkansas has been seriously impacted by an emerging strain of Aeromonas hydrophila, ...

New amyloid-reducing compound could be a preventive measure against Alzheimer's

2014-06-03

Scientists at NYU Langone Medical Center have identified a compound, called 2-PMAP, in animal studies that reduced by more than half levels of amyloid proteins in the brain associated with Alzheimer's disease. The researchers hope that someday a treatment based on the molecule could be used to ward off the neurodegenerative disease since it may be safe enough to be taken daily over many years. "What we want in an Alzheimer's preventive is a drug that modestly lowers amyloid beta and is also safe for long term use," says Martin J. Sadowski, MD, PhD, associate professor ...

Screening has prevented half a million colorectal cancers

2014-06-03

New Haven, Conn. – An estimated half a million cancers were prevented by colorectal cancer screening in the United States from 1976 to 2009, report researchers from the Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center at Yale Cancer Center. Their study appears in the journal Cancer. During this more than 30-year time span, as increasing numbers of men and women underwent cancer screening tests — including fecal occult blood testing, sigmoidoscopies, and colonoscopies — colorectal cancer rates declined significantly, the researchers found. The ...

Insect repellents more important than ever as tropical tourism increases

2014-06-03

Holidaymakers are being urged to use insect repellent to protect themselves against bites and the diseases they can spread, as trends show travel to tropical countries is rising among Britons. With the World Cup starting in Brazil next week and holiday season about to get under way, scientists from repellent testing facility arctec at the London School of Hygiene & Tropical Medicine today launch Bug Off - the first ever Insect Repellent Awareness Day to highlight the issue. They recommend applying repellents containing 20-50% DEET to the skin when in countries with ...

Left-handed fetuses could show effects of maternal stress on unborn babies

2014-06-03

Fetuses are more likely to show left-handed movements in the womb when their mothers are stressed, according to new research. Researchers at Durham and Lancaster universities say their findings are an indicator that maternal stress could have a temporary effect on unborn babies, adding that their research highlights the importance of reducing stress during pregnancy. However, the researchers emphasised that their study was not evidence that maternal stress led to fixed left-handedness in infants after birth. They said that some people might be genetically predisposed ...

Study of over 10,000 patients suggests men experience more pain after major surgery

2014-06-03

New research presented at this year's Euroanaesthesia meeting in Stockholm suggests that gender plays a part in pain experienced after surgery, with men feeling more pain following major surgery while women feel more pain after minor procedures. The study is by Dr Andreas Sandner-Kiesling, Dept of Anaesthesiology & Intensive Care, Medical University of Graz, Austria, and colleagues. "The influence of gender and sexes is a key issue of today's research in medicine. However, current literature in the field of perioperative medicine rarely focuses on this question," says ...

Increased mucins pinned to worsening cystic fibrosis symptoms

2014-06-03

CHAPEL HILL, N.C. – UNC School of Medicine researchers have provided the first quantitative evidence that mucins – the protein framework of mucus – are significantly increased in cystic fibrosis patients and play a major role in failing lung function. The research, published today in the Journal of Clinical Investigation, shows that a three-fold increase of mucins dramatically increases the water-draining power of the mucus layer. This hinders mucus clearance in the CF lung, resulting in infection, inflammation, and ultimately lung failure. "Our finding suggests that ...