Research

Random mutations play large role in cancer, study finds

GROWING PAINS As cells divide and grow to replenish and repair organs, accidental mutations may crop up in cancer-associated genes. A new study suggests such random mistakes are the source of 66 percent of mutations in cancer cells (illustrated here) across the board.

Researchers have identified new enemies in the war on cancer: ones that are already inside cells and that no one can avoid.

Random mistakes made as stem cells divide are responsible for about two-thirds of the mutations in cancer cells, researchers from Johns Hopkins University report in the March 24 Science. Across all cancer types, environment and lifestyle factors, such as smoking and obesity, contribute 29 percent of cancer mutations, and 5 percent are inherited.

That finding challenges the common wisdom that cancer is the product of heredity and the environment. “There’s a third cause and this cause of mutations is a major cause,” says cancer geneticist Bert Vogelstein.

Such random mutations build up over time and help explain why cancer strikes older people more often. Knowing that the enemy will strike from within even when people protect themselves against external threats indicates that early cancer detection and treatment deserve greater attention than they have previously gotten, Vogelstein says.

Vogelstein and biomathematician Cristian Tomasetti proposed in 2015 that random mutations are the reason some organs are more prone to cancer than others. For instance, stem cells are constantly renewing the intestinal lining of the colon, which develops tumors more often than the brain, where cell division is uncommon. That report was controversial because it was interpreted as saying that most cancers are the result of “bad luck.” The analysis didn’t include breast and prostate cancers. Factoring in those common cancers might change the results, some scientists said. And because the researchers looked at only cancer within the United States, critics charged that the finding might not hold up when considering places around the world where different environmental factors, such as infections, affect cancer development.

In the new study, Vogelstein, Tomasetti and Hopkins colleague Lu Li examined data from 69 countries about 17 types of cancer, this time including breast and prostate. Again, the researchers found a strong link between cancer and tissues with lots of dividing stem cells. The team also used DNA data and epidemiological studies to calculate the proportions of mutations in cancer cells caused by heredity or environmental and lifestyle factors. Remaining mutations were attributed to random errors — including typos, insertions or deletions of genes, epigenetic changes (alterations of chemical tags on DNA or proteins that affect gene activity) and gene rearrangements. Such errors unavoidably happen when cells divide.

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Chance cancer

For many organs, more of the mutations that lead to cancer come from random mistakes in DNA…

Watch Hilariously Awkward Robots Rap About Their Machine-Learning Skills

How do robots learn to act more like humans? Not by rapping. Researchers from Telecommunications Research Institute in Kyoto, Japan recently summarized their latest work [PDF] by having two robots show off their lyrical skills, and boy, is it cringe-worthy (Gizmodo called it “agonizingly awkward”) and amazing.

Two robots, Robovie and the super creepy android ERICA, rap their way through a parody of the Sugarhill Gang’s “

Yale Researchers Find That Autism Genes Helped Us to Become Smarter

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Those with autism face distinct challenges. These usually have to do with certain social deficits. That might be why the results of a new study appear a bit puzzling. Genes linked to autism spectrum disorders (ASD) were actually preserved through the process of evolution, Yale researchers concluded. These genes actually made us smarter.

If you find these results strange, consider the large numbers of scientists and engineers known to have Asperger’s syndrome. There are autistic savants as well, as the movie Rain Man can attest, which was based on a true story. Or perhaps you’ve seen the work of mind-blowing artist Stephen Wiltshire, who can draw panoramic scenes of whole cities with perfect detail, from his memory alone.

This was a genome-wide study, zeroing in on gene variants associated with ASD. Researchers examined 5,000 cases of autism and analyzed the genome of each participant. They focused on evolutionary gene selection, particularly on which genes were positively selected. One clue which led researchers to these findings was that, more genes associated with autism were preserved by evolution than would have been through sheer randomness.

Autistic…

Scientists move closer to building synthetic yeast from scratch

Saccharomyces cerevisiae yeast
BUDDING STAR With five more synthetic chromosomes built, scientists are closer to creating a synthetic genome for Saccharomyces cerevisiae yeast (shown).

Synthetic yeast is on the rise.

Scientists have constructed five more yeast chromosomes from scratch. The new work, reported online March 9 in Science, brings researchers closer to completely lab-built yeast.

“We’re doing it primarily to learn a little more about how cells are wired,” says geneticist Jef Boeke of the New York University Langone Medical Center. But scientists might also be able to tinker with a synthetic yeast cell more efficiently than a natural one, allowing more precise engineering of everything from antiviral drugs to biofuels.

Boeke was…

9 Up-Close Scientific Images from the Wellcome Image Awards

Each year, the Wellcome Image Awards highlight some of the most fascinating scientific images from around the world, as chosen by a panel of experts from the fields of science communications and medicine. The awards go to photographers and researchers who create “informative, striking and technically excellent images that communicate significant aspects of healthcare and biomedical science,” according to the Wellcome Trust, a biomedical research charity based in the UK. Here are nine of this year’s winning images:

ZEBRAFISH EYE AND NEUROMASTS

Ingrid Lekk and Steve Wilson, University College London

In this 4-day-old zebrafish embryo, a certain gene expressed in the lens of the eye and other parts of the visual system glows red when it’s activated. You can see the lens of the eye, the head, and neuromasts (those red dots around the rim of the image) glowing red, while the nervous system glows blue.

BLOOD VESSELS OF THE AFRICAN GREY PARROT

This image was created using a 3D reconstruction of a euthanized parrot. It models the system of blood vessels in the parrot’s head and neck down to the capillary level.

INTRAOCULAR LENS IRIS CLIP

Mark Bartley, Cambridge University Hospitals NHS Foundation Trust

Iris clips can treat nearsightedness, cataracts, and other eye issues. This photo shows an iris clip fitting on the eye of a 70-year-old patient. He regained nearly all his vision after the surgery.

BRAIN-ON-A-CHIP

Collin…

DNA may offer rapid road to Zika vaccine

Zika DNA vaccine
A Zika vaccine that’s made of DNA could be a safe and fast way to protect people from the virus, which can cause birth defects.

GIVE IT A SHOT

Last August, scientists injected a potential vaccine for Zika virus into a human being — just 3½ months after they had decided exactly what molecular recipe to use.

In the world of vaccine development, 3½ months from design to injection is “warp speed,” says vaccine researcher Nelson Michael of the Walter Reed Army Institute of Research in Silver Spring, Md. Clinical trials can take years and epidemics can burn out before vaccines make it to doctors’ shelves. Even vaccine creation is typically sluggish.

But in this case, the vaccine is a bit of DNA, which means scientists can get moving fast. Unlike some traditional methods, DNA vaccines don’t use dead or weakened viruses. Instead, they rely on a snippet of genetic material. This “naked” DNA carries, for example, the blueprints for Zika proteins. It’s just a long sequence of DNA blocks.

With DNA vaccines, “it’s easy to move very quickly,” says Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in Bethesda, Md. “All you need to do is get the right sequence, and Bingo! — you’re there.”

Historically, though, DNA vaccines have been deviled with drawbacks. “They work absolutely fantastically in mice,” says infectious diseases physician Anna Durbin of Johns Hopkins Bloomberg School of Public Health. But “they fail miserably when we use them in humans.”

Researchers at the infectious diseases institute will soon begin the second phase of human clinical trials for a DNA vaccine candidate for Zika, vaccine clinical researcher Julie Ledgerwood said February 6 in Washington, D.C., at an American Society for Microbiology meeting on biothreats. The virus made headlines last year as it continued its tear through the Americas, and scientists confirmed its link to birth defects, including microcephaly (SN: 12/24/16, p. 19). Ledgerwood hopes to see efficacy data on the vaccine by the end of 2018.

“Ultimately, we want a vaccine that can prevent congenital Zika infection,” she said. “We think the DNA vaccine platform is an opportunity to do things safely and very quickly.”

Government researchers aren’t betting everything on DNA, though, Fauci points out. “We’ve got multiple shots on goal here,” he says. A slew of other vaccine candidates, based on both traditional and new techniques, are also in the works. But the DNA vaccine has stepped up to the plate first, and the world will soon see if it can deliver.

“If it works,” Durbin says, “we’ve hit a home run.”

Making a DNA vaccine is simple, in principle. Scientists synthesize genes from a pathogen, insert them into a circular strand of DNA called a plasmid, make lots of copies and then inject the purified plasmid into a person. “You can literally build a DNA vaccine in weeks,” says Dan Barouch, an immunologist at Beth Israel Deaconess Medical Center and Harvard Medical School. The approach is flexible, too, he adds. Researchers can tinker with the DNA building blocks in the plasmid, adding bits from other viruses that might ultimately enhance the immune response.

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Immune trigger

For a DNA vaccine against Zika, scientists insert genes for Zika proteins into a circular piece of DNA called a plasmid. Many copies of the plasmid are injected into muscle. Some of the DNA travels into cells’ nuclei, where it is used to make messenger RNA. After exiting the nucleus, mRNA helps build Zika proteins, which can form viruslike particles that trigger the immune system to make antibodies.

Zika DNA vaccine process

Barouch’s team was the first to report a Zika DNA vaccine that offered protection in mice — in a study published last June in Nature. Five weeks later, he and colleagues reported in Science that the vaccine, and two others created via different strategies, worked well in monkeys, too. And in September, a team led by government scientists, and including Barouch as a coauthor, came out with two additional DNA vaccine candidates, described in Science.

It’s one of those additional candidates, called VRC 5283, that the infectious diseases institute plans to test in…

Why Making Decisions Stresses Some People Out

Canadian researchers have identified a common, avoidable stressor in some people’s decision-making process: Fear of a Better Option (FOBO). The team published their research online this month in the Personality and Social Psychology Bulletin.

Psychologists Jeffrey Hughes and Abigail A. Scholer of the University of Waterloo were curious about the type of person experts call a “maximizer”: that is, somebody who researches and considers every possible option before making a decision. “The general mindset of this type of person is something like, ‘I don’t want to do anything until I’ve figured out the right thing to do,’” Hughes told Real Simple. Hughes and Scholer conducted two different studies in the hopes of understanding the maximizer mindset.

For the “promotion-focused” maximizer, every choice hinges on whether or not it will help the individual gain social or financial status. These folks are generally able to make a choice and move on. “Assessment-focused” maximizers, on the other hand, have a difficult time letting go of any option, and may find themselves obsessing over choices they had initially ruled out.

They found that…

Jaywalking Behavior Varies by Culture, Study Confirms

Pedestrian culture varies quite a bit between cities across the world, especially when it comes to crosswalks, according to a new study in Royal Society Open Science (highlighted recently by Science magazine).

Japanese and French researchers teamed up to observe stoplights at four different intersections in Nagoya, Japan and three different sites in Strasbourg, France, hypothesizing that France’s individualistic society might encourage people to take more risks than Japan’s collectivist one.

They found that out of 1631 Japanese road crossings observed, only 2 percent of pedestrians crossed against the red light. By contrast, French pedestrians crossed against the light almost 42 percent of the 3814 crossings observed. Furthermore, even law-abiding French pedestrians stepped off the curb sooner than Japanese pedestrians when the light finally turned green.

In both countries, the number…

Jumping Around Can Help Kids Learn Math

Sitting quietly at a desk may be the preferred behavior for elementary-school students, but that doesn’t mean it’s the best way for them to learn. Researchers in Denmark have found that integrating whole-body movement into math lessons can significantly boost kids’ test scores. They published their research in the journal Frontiers of Human Neuroscience.

We all know that being active is good for our whole bodies. Recent studies have shown that those benefits reach all the way into the brain for both adults and kids. Intense exertion—the kind that gets your heart rate up—may improve alertness, and is linked to improved motor skills, sharper thinking, and better grades.

So we know that exercise can boost our brainpower. But can it help us learn? To find out, health scientists at the University of Copenhagen created a movement-centric, six-week math curriculum for elementary students. They recruited 165 pupils, all around the age of 7, and divided them into three groups. Some classes were given math…

New Ultrasound Tech Captures Clearest Imaging Ever of a 20-Week-Old Fetus

A London-based research project has produced the most detailed ultrasound image yet of a 20-week-old fetus, The Telegraph reports. iFind (intelligent fetal imaging and diagnosis), an initiative led by researchers at King’s College London, is working on computer-guided ultrasound technology so that scans can be automated and uniform as well as more accurate.

Typically, a 20-week ultrasound (also called a mid-pregnancy scan) helps detect fetal abnormalities like spina bifida, but current scans can’t catch everything. One researcher The Telegraph spoke to estimated that only about half of…