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WASHINGTON, June 16 (Xinhua) -- Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage. New research by a team of scientists at the University of Rochester has unveiled an important new mechanism that allows cells to recognize when they are under stress and prime the DNA repair machinery to respond to the threat of damage.Their findings will be published Friday in journal Science. Cells in the human body are constantly being exposed to stress from environmental chemicals or errors in routine cellular processes. While stress can cause damage, it can also provide the stimulus for undoing the damage.The scientists, led by biologists Vera Gorbunova and Andrei Seluanov, focused on the most dangerous type of DNA damage -- double strand breaks. Unrepaired, this type of damage can lead to premature aging and cancer. They studied how oxidative stress affects efficiency of DNA repair. Oxidative stress occurs when the body is unable to neutralize the highly-reactive molecules, which are typically produced during routine cellular activities.The research team found that human cells undergoing oxidative stress synthesized more of a protein called SIRT6. By increasing SIRT6 levels, cells were able to stimulate their ability to repair double strand breaks. When the cells were treated with a drug that inactivated SIRT6, DNA repair came to a halt, thus confirming the role of SIRT6 in DNA repair. Gorbunova notes that the SIRT6 protein is structurally related to another protein, SIR2, which has been shown to extend lifespan in multiple model organisms."SIRT6 also affects DNA repair when there is no oxidative stress," explains Gorbunova. "It's just that the effect is magnified when the cells are challenged with even small amounts of oxidative stress."SIRT6 allows the cells to be economical with their resources, priming the repair enzymes only when there is damage that needs to be repaired. Thus SIRT6 may be a master regulator that coordinates stress and DNA repair activities, according to Gorbunova.

ROME, Sept. 27 (Xinhua) -- The 30th general assembly of the International Council for Science (ICSU) kicked off here on Tuesday to address key global challenges, featuring over 275 scientists and experts from all over the world.The goal of the four-day event, hosted for the first time in Rome by the National Research Center (CNR) as Italy's scientific member at ICSU, is to discuss how science can contribute to boosting sustainable development, fighting climate change, increasing well-being and health in the changing urban environment and tackling the side-effects of progress.At the official opening ceremony, CNR president Francesco Profumo stressed that scientific research was the key to solving all current crises."It's during times of crises that inventions, great strategies and discoveries are made," he said quoting Albert Einstein."Global cooperation is crucial in addressing society's needs. In the wake of the negative economic outlook we are witnessing research and technological transfer can turn into efficient instruments to guide countries towards a solid development giving us the tools to tackle with lucidity the great obstacles we face," observed Profumo.Appealing to both private and public institutions, Profumo thus urged to boost strategic partnerships between universities, governments and research centres."We must create a network of knowledge-sharing together with enterprises in order to multiply and better implement growth and well-being opportunities. But in order to do so concrete political decisions must be undertaken and financial resources are needed," he added.

LOS ANGELES, June 5 (Xinhua) -- U.S. researchers have developed two new drugs that can prolong the lives of patients with advanced melanoma, it was announced on Sunday.Research on both drugs was presented at the on-going annual meeting of the American Society of Clinical Oncology in Chicago, according to HealthDay News.This is the first big news in years for treatment of melanoma, one of the deadliest forms of skin cancer and one that is notoriously difficult to treat, let alone cure, the report said.The first treatment, vemurafenib, inhibits a gene mutation harbored in half of all melanoma patients, but is not yet approved by the U.S. Food and Drug Administration.The other drug, Yervoy (ipilumumab), is an immune system therapy that won approval in March."The March FDA approval of ipilumumab (Yervoy) was the first new drug approval for melanoma in 13 years," said Tim Turnham, executive director of the Melanoma Research Foundation.The two drugs were developed by researchers at Memorial Sloan- Kettering Cancer Center in New York City, the report said."This is really a huge step toward personalized care in melanoma," Dr. Paul Chapman, lead author of the first study and the attending physician in the melanoma/sarcoma service at Memorial Sloan-Kettering, said in a statement. "This (vemurafenib) is the first successful melanoma treatment tailored to patients who carry a specific gene mutation in their tumor, and could eventually become one of only two drugs available that improves overall survival in advanced cancers.""Having two trials that show a benefit in survival in patients with melanoma, both of these in first-line settings -- we weren't here just a few years ago," said Dr. Stephen Hodi, director of the Melanoma Center at Dana Farber Cancer Institute in Boston. "These are huge, paradigm-shifting results for the field."In the vemurafenib trial, sponsored by the drug's makers, researchers randomly assigned 675 patients with advanced, inoperable melanoma to receive either the chemotherapy drug dacarbazine or vemurafenib. Vemurafenib targets the V600E mutation in the BRAF gene.At the three-month mark, patients taking vemurafenib were 63 percent less likely to die and 74 percent less likely to die or see their cancer return, compared to patients taking dacarbazine alone.Few patients had side effects in the vemurafenib group, although some did develop squamous cell carcinoma, a less dangerous form of skin cancer.This is the first drug that has been proven superior to chemotherapy in this group of hard-to-treat patients, the researchers said."There was such a substantial benefit that we recommended that patients cross over," Chapman said at a Sunday news briefing. "It' s unprecedented to report a trial this early. The median follow-up time was three months." Yet the differences between the two groups became evident almost immediately.Dr. Lynn Schuchter, co-moderator of the briefing and division chief of hematology-oncology at Abramson Cancer Center of the University of Pennsylvania in Philadelphia, said symptoms subsided in some patients almost immediately, enabling them to cut back on pain medication in just 72 hours."The median time to progression with dacarbazine was 1.6 months versus three months with vemurafenib, which is a huge difference," said Chapman.In the second study, about 500 patients were randomly picked to receive Yervoy plus dacarbazine or dacarbazine alone.Those taking both drugs lived a median of 11.2 months compared to 9.1 months for those taking dacarbazine alone. Time to recurrence of disease was about the same for both groups: 2.8 months and 2.6 months, respectively.Almost half of those taking the combination therapy were alive after one year, compared to 36.3 percent in the other group. After two years, the rates were 28.5 percent and 17.9 percent, respectively.By three years out, 20.8 percent of those in the combination group were alive compared with 12.2 percent of those taking chemotherapy alone.This is the first study to combine chemotherapy and immunotherapy both safely and effectively.A study to test vemurafenib in combination with Yervoy has already begun, according to HealthDay News.

WELLINGTON, Aug. 30 (Xinhua) -- Middle-aged women who wolf down their meals are much more likely to be overweight or obese than women who eat slower, New Zealand research has found.In what they claimed to be the first such nationwide study anywhere, Otago University researchers analyzed the relationship between self-reported speed of eating and body mass index (BMI) in more than 1,500 New Zealand women aged 40 to 50, an age group known to be at high risk of weight gain.The study by the university's department of human nutrition could lead to new and more successful methods of treating obesity, say the researchers.Study principal investigator Dr Caroline Horwath said that after adjusting for factors such as age, ethnicity, smoking, physical activity and menopause status, the researchers found that the faster women reported eating, the higher their BMI.Results from the two-year follow-up were expected to be published next year, and if analysis confirmed a causal relationship, the researchers would test interventions that focused on encouraging women to eat more slowly.

WASHINGTON, July 27 (Xinhua) -- Astronomers studying observations taken by NASA's Wide-field Infrared Survey Explorer (WISE) mission have discovered the first known "Trojan" asteroid orbiting the sun along with Earth, the U.S. National Aeronautics and Space Administration (NASA) announced Wednesday in a statement.Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn's moons share orbits with Trojans.Scientists had predicted Earth should have Trojans, but they have been difficult to find because they are relatively small and appear near the sun from Earth's point of view."These asteroids dwell mostly in the daylight, making them very hard to see," said Martin Connors of Athabasca University in Canada, lead author of a new paper on the discovery to be published Thursday in the journal Nature. "But we finally found one, because the object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans. WISE was a game-changer, giving us a point of view difficult to have at Earth 's surface."The WISE telescope scanned the entire sky in infrared light from January 2010 to February 2011. Connors and his team began their search for an Earth Trojan using data from NEOWISE, an addition to the WISE mission that focused in part on near-Earth objects, or NEOs, such as asteroids and comets. NEOs are bodies that pass within 28 million miles (45 million kilometers) of Earth 's path around the sun. The NEOWISE project observed more than 155, 000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.The team's hunt resulted in two Trojan candidates. One called 2010 TK7 was confirmed as an Earth Trojan after follow-up observations with the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii.The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth's orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid's orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).

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