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Archive - Jun 14, 2009

Tiny Bacterium in Ancient Ice May Hold Clues to Extraterrestrial Life

A novel species of ultramicrobacterium has been isolated from a 120,000-year-old, 3042-meter-deep Greenland glacier ice core by researchers at Pennsylvania State University. The scientists have provisionally called the new species Herminiimonas glaciei and suggested that it may hold clues to possible life forms on other planets. "These extremely cold environments are the best analogues of possible extraterrestrial habitats," said Dr. Jennifer Loveland-Curtze, lead author of the report. "The exceptionally low temperatures can preserve cells and nucleic acids for even millions of years. H. glaciei is one of just a handful of officially described ultra-small species and the only one so far from the Greenland ice sheet; studying these bacteria can provide insights into how cells can survive and even grow under extremely harsh conditions, such as temperatures down to -56˚C, little oxygen, low nutrients, high pressure, and limited space." The small size of H. glaciei probably helped it to survive in the liquid veins among ice crystals and the thin liquid film on their surfaces. Small cell size is considered to be advantageous for more efficient nutrient uptake, protection against predators, and occupation of micro-niches, and it has been shown that ultramicrobacteria are dominant in many soil and marine environments. This report was published in the June issue of the International Journal of Systematic and Evolutionary Microbiology. [Press release] [IJSEM abstract]

New Target for Treatment of Macular Degeneration

A new target for the diagnosis and treatment of age-related macular degeneration (AMD) has been identified by an international scientific team. The researchers demonstrated that blocking the activity of a protein called CCR3 can reduce the abnormal blood vessel growth that leads to macular degeneration. Furthermore, targeting this new protein may prove to be safer and more effective than the current treatment for the disease, which is directed at a protein called VEGF. The researchers detected the presence of CCR3 in eye tissue from humans with AMD, but not in eye tissue from individuals of similar age who did not have the disease. When CCR3 activity was blocked in model systems, either with drugs or through genetic engineering, the researchers saw a decrease in the generation of abnormal blood vessels. Drugs targeting CCR3 were significantly more effective than those targeting VEGF, implying that targeting of CCR3 could represent a new therapy for the two-thirds of patients who do not respond to current treatment. AMD affects 30 to 50 million people around the world, and that number is expected to double in the next decade as the “baby boomer” generation ages. The discovery of the role of CCR3 may enable physicians to catch the disease at its earliest stages, before blood vessels have fully infiltrated and destroyed the central portion of the retina, an area known as the macula, to cause vision loss. "An exciting implication of this study was that the CCR3 protein could be detected in early abnormal blood vessel growth, giving us the opportunity to prevent structural damage to the retina and preserve vision,” said Dr. Mary Elizabeth Hartnett, one of the study authors.

Key Gene Identified in Deadliest Breast Cancer

Scientists have identified a key gene in the pathogenesis of inflammatory breast cancer (IBC), which is the most lethal form of primary breast cancer, often striking women in the prime of life and causing death within 18 to 24 months. The disease-related gene is eIF4GI, a translation initiation factor. Researchers found that this gene is overexpressed in the majority of IBC patients and enables the formation of small, highly mobile clusters of cells (tumor emboli) that are responsible for the rapid metastasis that makes IBC such an effective killer. "The tragedy of IBC is that it is often misdiagnosed and misclassified,” said Dr. Robert Schneider, senior author of the report. “Rather than presenting as a “typical” lump, IBC looks like an inflammation of the breast and is frequently mistaken for an infection. Physicians often prescribe antibiotics, losing valuable time for treating this fast-moving killer." He noted that while IBC accounts for just several percent of all breast cancer cases, it takes a disproportionately high toll in mortality and has an incidence that is 50 percent higher in African American women. He added that there has been little progress in treating IBC over the past two decades, and there are no drugs specifically for this form of cancer. The new findings on eIF4GI could lead to the identification of new approaches, therapies, and a new class of drugs to target and treat IBC. This would be a critical development in the fight against IBC, which responds poorly to chemotherapy, radiation, or any other current treatments for breast cancer, Dr. Schneider noted. This research, conducted by scientists at New York University and George Washington University, was reported online in Nature Cell Biology on June 14.