Gene-editing damages DNA more than thought: study

Agencies
July 17, 2018

Paris, Jul 17:  A revolutionary gene editing technique hailed as the future of disease eradication and mooted for a Nobel Prize may be less precise and cause more cell damage than previously thought, researchers said Monday.

Lab experiments using mouse and human cells revealed that the CRISPR-Cas9 technique "frequently" caused "extensive" gene mutations, a study team reported.

"This is the first systematic assessment of unexpected events resulting from CRISPR-Cas9 editing," said Allan Bradley of the Wellcome Sanger Institute in England, where the team conducts research.

The research showed that "changes in the DNA have been seriously underestimated before now," said Bradley, who co-authored a study published in the journal Nature Biotechnology.

The mutations have not been shown to be harmful, nor benign.

"It is important that anyone thinking of using this technology for gene therapy proceeds with caution and looks very carefully to check for harmful effects," Bradley said in a statement issued by the institute.

First unveiled about six years ago, CRISPR-Cas9 allows scientists to insert, remove and correct a faulty sequence on a strand of DNA in a cell with pinpoint precision.

It has raised hopes that one-day disease-causing genes could be removed or altered before a baby is even born.

In recent years, CRISPR-Cas9 has repeatedly been predicted to win the Nobel Chemistry Prize.

CRISPRs -- clustered regularly interspaced short palindromic repeats -- are part of the immune defence system in bacteria, used to hone in on the exact spot on the genome where the cut should be made.

Cas9 is a protein used as "scissors" to snip through the faulty gene, which is then replaced or fixed by the cell's own DNA repair mechanism.

The technique's safety has not yet been proven, and it is not approved for use in human therapy.

So far, researchers have used it to improve hearing in mice going deaf and to fix a disease-causing mutation in cloned, early-stage human embryos.

But the new finding raises "safety implications," the team said.

They found "large genetic rearrangements such as DNA deletions and insertions" in cells, which could lead to important genes being switched on or off and causing dangerous changes.

The research also showed that standardized tests do not pick up damage to DNA caused by CRISPR-Cas9.

Experts not involved in the study said it was unclear how such large, unintended changes were not noticed before.

But, "the results give no reason to panic or to lose faith in the methods when they are carried out by those who know what they are doing," said Robin Lovell-Badge of The Francis Crick Institute, a biomedical research centre in London.

For Francesca Forzano, a consultant in clinical genetics and genomics with the Guy's and St Thomas' NHS Foundation Trust, the work showed that CRISPR-Cas9 "is much less safe than previously thought" and that safety-monitoring techniques were "not entirely adequate".

More research is needed before any clinical application of the method is considered, said Forzano.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
January 5,2020

Washington D.C., Jan 5: After a woman filed a lawsuit against a diet soda company, the California court has declared that the beverage does not promise to help buyers in losing weight.

The woman had gulped down the drink for over a decade but did not lose inches as a result.

The three-judge panel declared during the hearing: "The prevalent understanding of the term in (the marketplace) is that the 'diet' version of a soft drink has fewer calories than its 'regular' counterpart."

However, the members of the US 9th circuit court have felt that the consumers tend to make out something of their own that is unreasonable and eventually hamper the reputation of brands through a deceptive allegation, reports Fox News.

The response was due to a misleading case filed against Diet Dr Pepper by Shana Becerra from Santa Rosa, California. Shana claimed that she has been addictively purchasing the low-calorie beverage for the past 13 years hoping for losing some fat but failed to lose even a single inch.

The woman also stated that the attractive and fit models misled her into believing that drink will help her in perfecting her body like them.

However, the court's decision was that advertisements are for representational purposes only. "Cannot be reasonably understood to convey any specific meaning at all," as written by Judge Jay Bybee.

Shana had last week made such allegation against Diet coke as well where the court came to a similar verdict. She claimed that she had found various studies where it is evident that the artificial sweetener aspartame used in diet beverages actually boosts weight gain.

But the artificial sweetener is approved in by the concerned administrative department and thus is used in most American drinks.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
February 27,2020

Washington D.C, Feb 27: New research shows that adults who have low fruit and vegetable intake are more likely to be diagnosed with an anxiety disorder.

"For those who consumed less than 3 sources of fruits and vegetables daily, there was at least at 24% higher odds of anxiety disorder diagnosis," says the lead author of the Canadian Longitudinal Study, Karen Davison, who is a health science faculty member, nutrition informatics lab director at Kwantlen Polytechnic University, (KPU) and North American Primary Care Research Group Fellow.

"This may also partly explain the findings associated with body composition measures. As levels of total body fat increased beyond 36%, the likelihood of anxiety disorder was increased by more than 70%," states co-author Jose Mora-Almanza, a Mitacs Globalink intern who worked with the study at KPU.

"Increased body fat may be linked to greater inflammation. Emerging research suggests that some anxiety disorders can be linked to inflammation," says Davison.

In addition to diet and body composition measures, the prevalence of anxiety disorders also differed by gender, marital status, income, immigrant status and several health issues.

An important limitation of the study was that the assessment of anxiety disorders was mostly based upon self-reporting of a medical diagnosis.

"It is estimated that 10% of the global population will suffer from anxiety disorders which are a leading cause of disability," says Karen Davison

"Our findings suggest that comprehensive approaches that target health behaviours, including diet, as well as social factors, such as economic status, may help to minimize the burden of anxiety disorders among middle-aged and older adults, including immigrants," she concluded.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
June 20,2020

The World Health Organisation has warned that the COVID-19 pandemic is entering a "new and dangerous" phase. Thursday saw the most cases in a single day reported to the WHO.

Tedros Adhanom Ghebreyesus said the day had seen 150,000 new cases with half of those coming from the Americas and large numbers also from the Middle East and South Asia, the BBC reported.

He said the virus was still spreading fast and the pandemic accelerating.

He acknowledged people might be fed up with self-isolating and countries were eager to open their economies but he said that now was a time for extreme vigilance.

Maria van Kerkhove, technical lead of the WHO's COVID-19 response, told a press conference the pandemic is "accelerating in many parts of the world".

"While we have seen countries have some success in suppressing transmission and bringing transition down to a low level, every country must remain ready," she said.

Mike Ryan, the head of the WHO's Health Emergencies Programme, said that some countries had managed to flatten the peak of infections without bringing them down to a very low level.

"You can see a situation in some countries where they could get a second peak now, because the disease has not been brought under control," he said.

"The disease will then go away and reduce to a low level, and they could then get a second wave again in the autumn or later in the year."

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.