emerging technologies

Recent Articles

SickKids scientist calls for ‘national strategy’ to get genome sequencing covered in Canada

BY GENNA BUCK
NATIONAL POST
Whole-genome sequencing is not available in Canada yet under any provincial health plan. But Ontario’s health-care quality agency is currently reviewing a proposal to cover it for children with unexplained developmental delay, said Wendy Ungar, director of technology assessment at Toronto’s SickKids hospital, a major Canadian centre for this area of research. Continue Reading →

Filed under:

World’s first living organism with fully redesigned DNA created

BY IAN SAMPLE
THE GUARDIAN

Scientists have created the world’s first living organism that has a fully synthetic and radically altered DNA code.

The lab-made microbe, a strain of bacteria that is normally found in soil and the human gut, is similar to its natural cousins but survives on a smaller set of genetic instructions.

The bug’s existence proves life can exist with a restricted genetic code and paves the way for organisms whose biological machinery is commandeered to make drugs and useful materials, or to add new features such as virus resistance.

In a two-year effort, researchers at the Medical Research Council’s Laboratory of Molecular Biology in Cambridge read and redesigned the DNA of the bacterium Escherichia coli (E coli), before creating cells with a synthetic version of the altered genome.

The artificial genome holds 4m base pairs, the units of the genetic code spelled out by the letters G, A, T and C. Printed in full on A4 sheets, it runs to 970 pages, making the genome the largest by far that scientists have ever built.

“It was completely unclear whether it was possible to make a genome this large and whether it was possible to change it so much,” said Jason Chin, an expert in synthetic biology who led the project.

The DNA coiled up inside a cell holds the instructions it needs to function. When the cell needs more protein to grow, for example, it reads the DNA that encodes the right protein. The DNA letters are read in trios called codons, such as TCG and TCA.

Nearly all life, from jellyfish to humans, uses 64 codons. But many of them do the same job. In total, 61 codons make 20 natural amino acids, which can be strung together like beads on a string to build any protein in nature. Three more codons are in effect stop signs: they tell the cell when the protein is done, like the full stop marking the end of this sentence.

The Cambridge team set out to redesign the E coli genome by removing some of its superfluous codons. Working on a computer, the scientists went through the bug’s DNA. Whenever they came across TCG, a codon that makes an amino acid called serine, they rewrote it as AGC, which does the same job. They replaced two more codons in a similar way.

More than 18,000 edits later, the scientists had removed every occurrence of the three codons from the bug’s genome. The redesigned genetic code was then chemically synthesised and, piece by piece, added to E coli where it replaced the organism’s natural genome. The result, reported in Nature, is a microbe with a completely synthetic and radically altered DNA code. Known as Syn61, the bug is a little longer than normal, and grows more slowly, but survives nonetheless.

“It’s pretty amazing,” said Chin. When the bug was created, shortly before Christmas, the research team had a photo taken in the lab with a plate of the microbes as the central figure in a recreation of the nativity.

Such designer lifeforms could come in handy, Chin believes. Because their DNA is different, invading viruses will struggle to spread inside them, making them in effect virus-resistant. That could bring benefits. E coli is already used by the biopharmaceutical industry to make insulin for diabetes and other medical compounds for cancer, multiple sclerosis, heart attacks and eye disease, but entire production runs can be spoiled when bacterial cultures are contaminated with viruses or other microbes. But that is not all: in future work, the freed-up genetic code could be repurposed to make cells churn out designer enzymes, proteins and drugs.

In 2010, US scientists announced the creation of the world’s first organism with a synthetic genome. The bug, Mycoplasma mycoides, has a smaller genome than E coli – about 1m base pairs – and was not radically redesigned. Commenting on the latest work, Clyde Hutchison, from the US research group, said: “This scale of genome replacement is larger than any complete genome replacement reported so far.”

“They have taken the field of synthetic genomics to a new level, not only successfully building the largest ever synthetic genome to date, but also making the most coding changes to a genome so far,” said Tom Ellis, a synthetic biology researcher at Imperial College London.

But the records may not stand for long. Ellis and others are building a synthetic genome for baker’s yeast, while Harvard scientists are making bacterial genomes with more coding changes. That the redesigned E coli does not grow as well as natural strains is not surprising, Ellis added. “If anything it’s surprising it grows at all after so many changes,” he said.

Continue Reading →

Filed under:

Scientists may have found a way to treat cancer without chemotherapy by replicating our body’s own self-destruct system

BY LISA SCHONHAAR
BUSINESS INSIDER
Every day, millions of cells in our bodies “kill” themselves and are quickly removed.
While the mechanism may sound dramatic, it’s for our own good. The process ensures that potentially harmful cells destroy themselves and protects us from diseases.
Cancer cells, however, can protect themselves from self-destruction by ignoring our immune system’s cell-death signals — and that’s precisely what makes them so dangerous.
Continue Reading →

Filed under:

U.S. scientists try 1st gene editing in the body

The Associated Press
CBC.ca

Scientists for the first time have tried editing a gene inside the body in a bold attempt to permanently change a person’s DNA to try to cure a disease.

The experiment was done Monday in California on 44-year-old Brian Madeux. Through intravenous (IV), he received billions of copies of a corrective gene and a genetic tool to cut his DNA in a precise spot.

“It’s kind of humbling” to be the first to test this, said Madeux, who has Hunter syndrome, a metabolic disease. “I’m willing to take that risk. Hopefully it will help me and other people.”

Signs of whether it’s working may come in a month; tests will show for sure in three months.

If it’s successful, it could give a major boost to the fledgling field of gene therapy. Scientists have edited human genes before, altering cells in the lab that are then returned to patients. There also are gene therapies that don’t involve editing DNA.

But these methods can only be used for a few types of diseases. Some give results that may not last. Some others supply a new gene like a spare part, but can’t control where it inserts in the DNA, possibly causing a new problem like cancer.

This time, the gene tinkering is happening in a precise way inside the body. It’s like sending a mini-surgeon along to place the new gene in exactly the right location.

“We cut your DNA, open it up, insert a gene, stitch it back up. Invisible mending,” said Dr. Sandy Macrae, president of Sangamo Therapeutics, the California company testing this for two metabolic diseases and hemophilia. “It becomes part of your DNA and is there for the rest of your life.” Continue Reading →

Filed under:

Crispr: Chinese scientists to pioneer gene-editing trial on humans

BY NICKY WOOLF
THE GUARDIAN

A team of Chinese scientists will be the first in the world to apply the revolutionary gene-editing technique known as Crispr on human subjects. Led by Lu You, an oncologist at Sichuan University’s West China hospital in Chengdu, China, the team plan to start testing cells modified with Crispr on patients with lung cancer in August, according to the journal Nature. Crispr is a game-changer in bioscience; a groundbreaking technique which can find, cut out and replace specific parts of DNA using a specially programmed enzyme named Cas9. Its ramifications are next to endless, from changing the color of mouse fur to designing malaria-free mosquitoes and pest-resistant crops to correcting a wide swath of genetic diseases like sickle-cell anaemia in humans. The concept of editing human DNA has often been controversial. Continue Reading →

Filed under:

Gene therapy partially restores vision in rare blindness disorder

BY IAM SAMPLE
THE GUARDIAN

Two men with progressive blindness have regained some of their vision after taking part in the first clinical trial of a gene therapy for the condition. The men were among six patients to have experimental treatment for a rare, inherited, disorder called choroideremia, which steadily destroys eyesight and leaves people blind in middle age. After therapy to correct a faulty gene, the men could read two to four more lines on an optician’s sight chart, a dramatic improvement that has held since the doctors treated them. One man was treated more than two years ago. The other four patients, who had less advanced disease and good eyesight before the trial, had better night vision after the therapy. Continue Reading →

Filed under:

Britain gives scientist go-ahead to genetically modify human embryos

BY KATE KELLAND
REUTERS

Scientists in Britain have been give the go-ahead to edit the genes of human embryos for research purposes, using a technique that some say could eventually be used to create “designer babies”. Less than a year after Chinese scientists caused an international furor by saying they had genetically modified human embryos, Kathy Niakan, a stem cell scientist from London’s Francis Crick Institute, was granted a license to carry out similar experiments. “The Human Fertilisation and Embryology Authority (HFEA) has approved a research application from the Francis Crick Institute to use new ‘gene editing’ techniques on human embryos,” Niakan’s lab said on Monday. It said the work carried out “will be for research purposes and will look at the first seven days of a fertilized egg’s development, from a single cell to around 250 cells”. The scientists will not be allowed to develop the modified embryos for clinical purposes or implant them into any women. Continue Reading →

Filed under: