Syndicate content

Archive - Nov 2013

November 9th

RNA Target Identified for ALS and Frontotemporal Degeneration

A team of scientists led by researchers from the University of California, San Diego School of Medicine and Ludwig Institute for Cancer Research have identified a novel therapeutic approach for the most frequent genetic cause of ALS (Lou Gehrig’s disease), a disorder of the regions of the brain and spinal cord that control voluntary muscle movement, and also for frontal temporal degeneration, the second most frequent dementia. Published online on October 29, 2013 in PNAS, the study establishes using segments of genetic material called antisense oligonucleotides – ASOs – to block the buildup and selectively degrade the toxic RNA that contributes to the most common form of ALS, without affecting the normal RNA produced from the same gene. The new approach may also have the potential to treat frontotemporal degeneration or frontotemporal dementia (FTD), a brain disorder characterized by changes in behavior and personality, language, and motor skills that also causes degeneration of regions of the brain. In 2011, scientists found that mutation of a specific gene known as C9orf72 is the most common genetic cause of ALS. It is a very specific type of mutation which, instead of changing the protein, involves a large expansion, or repeated sequence of a set of nucleotides – the basic component of RNA, as well as DNA. A normal C9orf72 gene contains fewer than 30 of the nucleotide repeat unit, GGGGCC. The mutant gene may contain hundreds of repeats of this unit, which generate a repeat containing RNA that the researchers show aggregates into foci.

30,000 Attending Neuroscience Annual Meeting in San Diego

Nearly 30,000 attendees will gather in San Diego for the world’s largest source of emerging news about brain science and health: Neuroscience 2013, November 9–13. With more than 15,000 scientific presentations, 600 exhibitors, and 34 professional development workshops and networking functions, the annual meeting of the Society for Neuroscience (SfN) provides an extraordinary opportunity to share information, learn and discuss the latest brain research findings, and attend public events on the mind, creativity, and art. “Aided by new technology and scientific innovations, neuroscience is on the cusp of revolutionary advances — and nowhere is that better on display than at Neuroscience 2013,” said SfN President Larry Swanson, Ph.D., Professor of Biological Sciences, Neurology, and Psychology at the University of Southern California. “Each year the meeting showcases valuable new research about brain structure, disease, and function in the relentless pursuit of knowledge and understanding and the hope for better medical treatments. The spirit of innovation and creativity is evident in the many lectures and presentations, and in the buzz of scientific discourse on the poster floor,” he added. Recent investment in neuroscience in the U.S., Europe, Canada, China, and elsewhere, has highlighted the importance of scientific discovery in addressing mental and physical health worldwide. More than 1 billion people suffer from 1,000 brain and nervous system diseases and disorders that result in heavy financial burdens to healthcare systems and to families and society each year. Highlights of this year’s diverse program of events include: “Dialogues between Neuroscience and Society” lecture featuring Ed Catmull, Ph.D., president of Pixar and Walt Disney Animation Studios. Dr.

Genetic Variation Increases Risk of Kidney Disease Progression in African-Americans—Link to Sleeping Sickness Resistance

New research provides direct evidence that genetic variations in some African Americans with chronic kidney disease contribute to a more rapid decline in kidney function compared with white Americans. The research, led by investigators from the University of Maryland School of Medicine and Johns Hopkins University, may help explain, in part, why even after accounting for differences in socioeconomic background, end-stage kidney disease is twice as prevalent among blacks as whites. Results were published online on November 9, 2013 in the New England Journal of Medicine. “What we found is pretty remarkable — that variations in a single gene account for a large part of the racial disparity in kidney disease progression and risk for end-stage kidney disease,” says co-lead author and nephrologist Afshin Parsa, M.D., M.P.H., assistant professor of medicine and member of the Program in Personalized and Genomic Medicine at the University of Maryland School of Medicine. “If it were possible to reduce the effect of this gene, there could be a very meaningful decrease in progressive kidney and end-stage kidney disease within blacks.” Previous landmark discoveries had revealed that two common variants within a gene called apolipoprotein L1 (APOL1) were strongly associated with non-diabetic end-stage renal disease in blacks. Having only one copy of the variant APOL1 gene variant is associated with a health benefit – protection against African sleeping sickness, a potentially lethal parasitic infection transmitted by the tsetse fly (image), found only in sub-Saharan Africa. However, people with two copies of the variant are at a higher risk for kidney disease.

November 8th

Reduced Mitochondrial DNA May Lead to Breast Cancer Metastasis

For years, scientists have observed that tumor cells from certain breast cancer patients with aggressive forms of the disease contained low levels of mitochondrial DNA. But, until recently, no one was able to explain how this characteristic influenced disease progression. Now, University of Pennsylvania researchers have revealed how a reduction in mitochondrial DNA content leads human breast cancer cells to take on aggressive, metastatic properties. The work, published online on November 4, 2013, in the journal Oncogene, breaks new ground in understanding why some cancers progress and spread faster than others and may offer clinicians a biomarker that would distinguish patients with particularly aggressive forms of disease, helping personalize treatment approaches. The study was led by the Penn School of Veterinary Medicine’s Dr. Manti Guha, a senior research investigator, and Dr. Narayan Avadhani, Harriet Ellison Woodward Professor of Biochemistry in the Department of Animal Biology. Additional Penn Vet collaborators included Drs. Satish Srinivasan, Gordon Ruthel, Anna K. Kashina, and Thomas Van Winkle. They teamed with Dr. Russ P. Carstens of Penn’s Perelman School of Medicine and Drs. Arnulfo Mendoza and Chand Khanna of the National Cancer Institute. Mitochondria, the so-called “powerhouses” of mammalian cells, are also a signaling hub. They are heavily involved in cellular metabolism as well as in apoptosis, the process of programmed cell death by which potentially cancerous cells can be killed before they multiply and spread. In addition, mitochondria contain their own genomes, which code for specific proteins and are expressed in coordination with nuclear DNA to regulate the provision of energy to cells.

New Species of Scorpion Discovered in Turkey

Scientists have discovered and described a new species of scorpion, Euscorpius lycius, coming from the area of ancient Lycia, nowadays the regions of the Muğla and Antalya Provinces in Southwestern Turkey. With the new discovery, the scorpions from this genus found in the country go up to a total of five known species. The study was published in the open-access journal ZooKeys and featured on the cover of the August 8, 2013 print issue. Euscorpius is a genus of scorpions, commonly called small wood-scorpions. As their name suggests, these scorpions don't impress with a large size, the biggest representative being ony approximately 5 cm long. The group is widespread in North Africa and across Europe. Euscorpius scorpions are relatively harmless, with poison that has effects similar to a mosquito bite. The new species is named after the historical region of Ancient Lycia, which is referenced in Egyptian and Ancient Greek myths. Like the mystical history of the region, the new species is rather secretive and can be found mainly in pine forests at night hidden away in pine forests, crawling on rocks or sitting on stone garden walls. All localities where the species was found were humid and cool, with calcareous stones covered with moss. The new scorpion is a relatively small representative, reaching a size ranging between two and two-and-a-half centimeters. The color of the adult representatives is pale, between brown and reddish, with pedipalps, or claws, usually darker than the rest of the body. "A total of 26 specimens belonging to the new species were collected from Antalya and Muğla Province, in the south-west of Turkey." explains Dr. Ersen Yağmur, the lead author of the study.

Cost-Effective Method Accurately Orders DNA Sequencing along Entire Chromosomes

A new computational method has been shown to quickly assign, order, and orient DNA sequencing information along entire chromosomes. The method may help overcome a major obstacle that has delayed progress in designing rapid, low-cost -- but still accurate -- ways to assemble genomes from scratch. Data gleaned through this new method can also validate certain types of chromosomal abnormalities in cancer, research findings indicate. The advance was reported online on November 3, 2013 in Nature Biotechnology by several University of Washington scientists led by Dr. Jay Shendure, associate professor of genome sciences. Existing technologies can quickly produce billions of "short reads" of segments of DNA at very low cost. Various approaches are currently used to put the pieces together to see how DNA segments line up to form larger stretches of the genetic code. However, current methods produce a highly fragmented genome assembly, lacking long-range information about what sequences are near what other sequences, making further biological analysis difficult. "Genome science has remained remarkably distant from routinely assembling genomes to the standards set by the Human Genome Project," said the researchers. They noted that the Human Genome Project tapped into many different techniques to achieve its end result. Many of these are too expensive, technically difficult, and impractical for large-scale initiatives such as the Genome 10K Project, which aims to sequence and assemble the genomes of 10,000 vertebrate species. Members of the Shendure lab that developed what they hope will be a more scalable strategy were Drs. Joshua N. Burton, Andrew Adey, Rupali P. Patwardhan, Ruolan Qiu, and Jacob O. Kitzman.

Unique Change in Protein Structure Guides Production of RNA from DNA

One of biology's most fundamental processes is something called transcription. It is just one step of many required to build proteins—and without it life would not exist. However, many aspects of transcription remain shrouded in mystery. But now, scientists at the Gladstone Institutes in San Francisco are shedding light on key aspects of transcription, and in so doing are coming even closer to understanding the importance of this process in the growth and development of cells—as well as what happens when this process goes awry. In the November 7, 2013 issue of Molecular Cell, researchers in the laboratory of Gladstone Investigator Melanie Ott, M.D., Ph.D., describe the intriguing behavior of a protein called RNA polymerase II (RNAPII) (see image). The RNAPII protein is an enzyme, a catalyst that guides the transcription process by copying DNA into RNA, which forms a disposable blueprint for making proteins. Scientists have long known that RNAPII appears to stall or "pause" at specific genes early in transcription. But they were not sure as to why. "This so-called 'polymerase pausing' occurs when RNAPII literally stops soon after beginning transcription for a short period before starting up again," explained Dr. Ott, who is also a professor of medicine at the University of California, San Francisco, with which Gladstone is affiliated. "All we knew was that this behavior was important for the precise transcription of DNA into RNA, so we set out to understand how, when, and—most importantly—why." The research team focused its efforts on a segment of RNAPII called the C-terminal domain, or CTD. This section is most intimately involved with transcription regulation. Previous research had found that CTD's chemical structure is modified before and during transcription.

November 7th

Hope Builds for Drug That Might Shut Down Variety of Cancers

The most frequently mutated gene across all types of cancers is a gene called p53 (image shows 3-D structure of p53 protein). Unfortunately, it has been difficult to directly target this gene with drugs. Now a multi-institutional research team, led by Dr. Lewis Cantley and investigators at Weill Cornell Medical College, has identified a family of enzymes they say is crucial for the growth of cancers that have genetic aberrations in p53. Targeting these enzymes with novel agents might prevent the growth of p53 mutant cancers, thereby benefiting a broad spectrum of cancer patients, including those with breast, ovarian, lung, colorectal, and brain tumors. In the November 7, 2013 issue of Cell, investigators pinpoint two cellular enzymes -- Type 2 phosphatidylinositol-5-phosphate 4-kinases α and β (Type 2 PIP kinases) -- as essential for cancer growth when cells have lost p53, the powerful tumor-suppressor gene long dubbed the "guardian of the genome." More than half of all cancers lose this gene, allowing these cancers to grow at will. The researchers discovered that the Type 2 PIP kinases are not critical for the growth of normal cells but become essential for cell growth when p53 is lost due to mutations or deletions. The scientists showed, in animal and lab studies of human cancer cells, that targeting these molecules effectively shuts down the growth of p53 mutant cancers. Although the studies were conducted in human breast cancer cells, the researchers believe Type 2 PIP kinase inhibitors could block the growth of various cancers with a mutated or missing p53 gene. "The fact that one can delete the Type 2 PIP kinases in normal human cells or in mice with essentially no effect on cell survival suggests that inhibitors of these enzymes should have little toxicity," says Dr.

Scientists Discover New Driver of Estrogen-Receptor-Positive Breast Cancer

A team of researchers at the Univeristy of Texas (UT) Southwestern has found that, as cholesterol is metabolized, a potent stimulant of breast cancer is created – one that fuels estrogen-receptor-positive breast cancers, and that may also defeat a common treatment strategy for those cancers. The multidisciplinary team discovered that a cholesterol metabolite called 27-hydroxycholesterol, or 27HC, promotes tumor growth in estrogen-receptor-positive breast cancers, which are the most common type of breast cancer. Estrogen-receptor-positive breast cancer was previously believed to be stimulated primarily by the female sex hormone estrogen and it is commonly treated using endocrine-based medications that starve tumors of estrogen. The discovery of 27HC as another driver of breast cancer may explain why endocrine-based therapy is often unsuccessful, providing a new target for therapy, the researchers say. “This information can be used to develop new therapies that inhibit 27HC action or production, or increase its metabolism, in effect cutting the cancer off from a key growth stimulator,” said senior author Dr. Philip Shaul, Professor and Vice Chair for Research in Pediatrics and a member of the Harold C. Simmons Comprehensive Cancer Center. Implications of the research that appears online in Cell Reports on November 7, 2013, are significant. One million new cases of breast cancer are diagnosed each year, and about two-thirds of those are hormone-receptor-positive, meaning they contain receptors for the hormones estrogen and/or progesterone, according to the American Cancer Society. Estrogen-receptor-positive breast cancer is particularly prevalent following menopause.

Drug Breakthrough for African Sleeping Sickness, Other Tropical Parasitic Infections

Scientists at the University of Oulu, Finland, and at the Helmholtz Center Berlin (HZB) have shown the way to new directions in drug development against African sleeping sickness and other tropical parasitic infections. This was based on the structural analysis of the enzyme thiolase, which plays a central role in lipid metabolism in the parasite that causes sleeping sickness. The researchers examined the biomolecule’s structure at the MX beamline of the electron storage ring, BESSY II, at the HZB. The results were published online on August 2, 2013 in the Biochemical Journal. Sleeping sicknesses – african trypanosomiasis, kala-azar, indian leishmaniasis – are infections caused by tropical parasites. Millions get sick from them each year and thousands end up dying. Anti-parasitic drugs are expensive and often have a host of unwanted side effects. In decades, there have been no new effective therapies. This is reason enough for the World Health Organization (WHO) to consider research, which can lead to the development of new anti-parasitic drugs, a top priority. Now, Professor Rik Wierenga and his team at Oulu University have paved the way for this type of research by shedding light on the structure of the enzyme thiolase. Thiolase figures prominently in parasitic lipid metabolism. According to Dr. Wierenga, “key is knowing the geometry of the enzyme’s active site. This is the place where lipids that play a central role in parasitic metabolism attach and where chemical reactions that convert lipids into other substances take place.” This is why it’s important to investigate the active site’s structure and function: “It enables us to develop lipid-like substances that firmly attach to the active site and block it.” The molecules that are involved represent the ideal starting points for new drug development.