Random Mutations Play Major Role in Cancer

Cancer OddsWe humans are wired to search for a causative agent when something bad happens. When someone develops cancer, we seek a reason. Maybe cancer runs in the family. Or perhaps the person smoked, never wore sunscreen, or drank too much alcohol. At some level, those are reasonable assumptions, as genes, lifestyle, and environment do play important roles in cancer. But a new study claims that the reason why many people get cancer is simply just bad luck.

This bad luck occurs during the normal process of cell division that is essential to helping our bodies grow and remain healthy. Every time a cell divides, its 6 billion letters of DNA are copied, with a new copy going to each daughter cell. Typos inevitably occur during this duplication process, and the cell’s DNA proofreading mechanisms usually catch and correct these typos. However, every once in a while, a typo slips through—and if that misspelling happens to occur in certain key areas of the genome, it can drive a cell onto a pathway of uncontrolled growth that leads to cancer. In fact, according to a team of NIH-funded researchers, nearly two-thirds of DNA typos in human cancers arise in this random way.

The latest findings should help to reassure people being treated for many forms of cancer that they likely couldn’t have prevented their illness. They also serve as an important reminder that, in addition to working on better strategies for prevention, cancer researchers must continue to pursue innovative technologies for early detection and treatment.

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Happy New Year: Looking Back at 2016 Research Highlights

Science Breakthroughs of the Year 2016Happy New Year! While everyone was busy getting ready for the holidays, the journal Science announced its annual compendium of scientific Breakthroughs of the Year. If you missed it, the winner for 2016 was the detection of gravitational waves—tiny ripples in the fabric of spacetime created by the collision of two black holes 1.3 billion years ago! It’s an incredible discovery, and one that Albert Einstein predicted a century ago.

Among the nine other advances that made the first cut for Breakthrough of the Year, several involved the biomedical sciences. As I’ve done in previous years (here and here), I’ll kick off this New Year by taking a quick look of some of the breakthroughs that directly involved NIH support:

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Genome Sequencing: Exploring the Diagnostic Promise

Hanners Family

Caption: Whole genome sequencing revealed that sisters Addison and Trinity Hanners, ages 7 and 10, shown here with their mother Hanna, have a rare syndrome caused by a mutation in the MAGEL2 gene.
Credit: Courtesy of the Hanners family

At the time that we completed a draft of the 3 billion letters of the human genome about a decade ago, it would have cost about $100 million to sequence a second human genome. Today, thanks to advances in DNA sequencing technology, it will soon be possible to sequence your genome or mine for  $1,000 or less. All of this progress has made genome sequencing a far more realistic clinical option to consider for people, especially children, who suffer from baffling disorders that can’t be precisely diagnosed by other medical tests.

While researchers are still in the process of evaluating genome sequencing for routine clinical use, and data analysis continues to be a major challenge, one area of considerable promise centers on neurodevelopmental disorders. Such disorders—which affect about 3 percent of children—range from relatively common conditions like autism spectrum disorder to very rare conditions that impair the development of the brain or central nervous system. In the latest study, an NIH-funded research team reports that sequencing either a patient’s whole genome or whole exome (the 1.5 percent of the genome that encodes proteins) appears to be an effective—as well as a cost-effective—strategy for diagnosing neurodevelopmental disorders that have eluded diagnosis through standard means.

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Taking a New Look at Artificial Sweeteners

Packets of artificial sweetenersDiet sodas and other treats sweetened with artificial sweeteners are often viewed as guilt-free pleasures. Because such foods are usually lower in calories than those containing natural sugars, many have considered them a good option for people who are trying to lose weight or keep their blood glucose levels in check. But some surprising new research suggests that artificial sweeteners might actually do the opposite, by changing the microbes living in our intestines [1].

To explore the impact of various kinds of sweeteners on the zillions of microbes living in the human intestine (referred to as the gut microbiome), an Israeli research team first turned to mice. One group of mice was given water that contained one of two natural sugars: glucose or sucrose; the other group received water that contained one of three artificial sweeteners: saccharin (the main ingredient in Sweet’N Low®), sucralose (Splenda®), or aspartame (Equal®, Nutrasweet®). Both groups ate a diet of normal mouse chow.

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New Strategies in Battle Against Antibiotic Resistance

Klebsiella pneumoniae Bacteria

Caption: Colorized scanning-electron micrograph showing carbapenem-resistant Klebsiella pneumoniae interacting with a human white blood cell.
Credit: National Institute of Allergy and Infectious Diseases, NIH

Over the past year, the problem of antibiotic resistance has received considerable attention, with concerns being raised by scientists, clinicians, public health officials, and many others around the globe. These bacteria are found not only in hospitals, but in a wide range of community settings. In the United States alone, antibiotic-resistant bacteria cause roughly 2 million infections per year, and 23,000 deaths [1].

In light of such daunting statistics, the need for action at the highest levels is clear, as is demonstrated by an Executive Order issued today by the President. Fighting antibiotic resistance is both a public health and national security priority. The White House has joined together with leaders from government, academia, and public health to create a multi-pronged approach to combat antibiotic resistance. Two high-level reports released today—the White House’s National Strategy for Combating Antibiotic-Resistant Bacteria (CARB) and the complementary President’s Council of Advisors on Science and Technology (PCAST) Report to the President on Combating Antibiotic Resistance—outline a series of bold steps aimed at addressing this growing public health threat.

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