Epigenetic changes can drive cancer, study shows

Cancer has long been thought to be primarily a genetic disease, but in recent decades scientists have come to believe that epigenetic changes — which don’t change the DNA sequence but how it is ‘read’ — also play a role in cancer. In particular DNA methylation, the addition of a methyl group (or molecule), is an epigenetic switch that can stably turn off genes, suggesting the potential to cause cancer just as a genetic mutation can. Until now, however, direct evidence that DNA methylation drives cancer formation was lacking.Researchers at the USDA/ARS Children’s Nutrition Research Center at Baylor College of Medicine and Texas Children’s Hospital have now created a mouse model providing the first in vivo evidence that epigenetic alterations alone can cause cancer. Their report appears in the Journal of Clinical Investigation.”We knew that epigenetic changes are associated with cancer, but didn’t know whether these were a cause or consequence of cancer. Developing this new approach for ‘epigenetic engineering’ allowed us to test whether DNA methylation changes alone can drive cancer,” said Dr. Lanlan Shen, associate professor of pediatrics at Baylor and senior author of the study.Shen and colleagues focused on p16, a gene that normally functions to prevent cancer but is commonly methylated in a broad spectrum of human cancers. They devised an approach to engineer DNA methylation specifically to the mouse p16 regulatory region (promoter). As intended, the engineered p16 promoter acted as a ‘methylation magnet’. As the mice reached adulthood, gradually increasing p16 methylation led to a higher incidence of spontaneous cancers, and reduced survival.”This is not only the first in vivo evidence that epigenetic alteration alone can cause cancer,” said Shen. “This also has profound implications for future studies, because epigenetic changes are potentially reversible. …

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Obese adolescents not getting enough sleep?

Lack of sleep and obesity have been associated with an increased risk of cardiovascular and metabolic diseases in adults and young children. However, the association is not as clear in adolescents, an age group that is known to lack adequate sleep and have an overweight and obesity prevalence rate of 30% in the US. In a new study scheduled for publication in The Journal of Pediatrics, researchers found that cardiometabolic risk in obese adolescents may be predicted by typical sleep patterns.Heidi B. IglayReger, PhD, and colleagues from the University of Michigan and Baylor University studied 37 obese adolescents (11-17 years of age). Metabolic syndrome characteristics (fasting cholesterol and blood sugar, waist circumference, body mass index [BMI], and blood pressure) were measured to create a continuous cardiometabolic risk score. The adolescents were fitted with a physical activity monitor, which was worn 24 hours a day for seven days, to measure typical patterns of physical activity and sleep.One-third of the participants met the minimum recommendation of being physically active at least 60 minutes a day. Most participants slept approximately seven hours each night, usually waking up at least once. Only five of the participants met the minimal recommended 8.5 hours of sleep per night. Even after controlling for factors that may impact cardiometabolic risk, like BMI and physical activity, low levels of sleep remained a significant predictor of cardiometabolic risk in obese teens. This shows that even among those already considered to be at risk for cardiometabolic disease, in this case obese teens’ decreased sleep duration was predictive of increased cardiometabolic risk.This study cannot determine whether lack of sleep causes cardiometabolic disease or if obesity itself causes sleep disturbances. …

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Hybrid cars are status symbol of sorts for seniors

Oct. 10, 2013 — Paying extra bucks to “go green” in a hybrid car may pay off in self-esteem and image for older drivers, as well as give a healthy boost to the environment, according to a Baylor University study.The finding is significant because some segments of the older-consumer population control a considerable share of the discretionary income in the United States, and the population size of the “mature market” is growing rapidly, researchers said.The study is published in the journal Human Factors and Ergonomics in Manufacturing and Service Industries.”If I want to pay $5 for a ‘green’ detergent or sponge, I’ll know that I’m helping the environment. But those things aren’t highly visible. Other people aren’t going to notice,” said Jay Yoo, Ph.D., an assistant professor of family and consumer sciences in Baylor’s College of Arts & Sciences.Researchers analyzed a national cross-sectional survey of 314 consumers age 60 and older who had bought hybrid cars. The study showed that their satisfaction was influenced by social values — including pride and prestige — as well as quality and price, not only in vehicle purchase but in future savings on gasoline expenses.Those three variables — social value, price and quality –are significant in enhancing senior citizens’ customer loyalty as shown by repurchase intention and positive word-of-mouth, Yoo said. Emotional values — such as excitement — did not significantly influence their purchase intention or satisfaction, according to the study.”The findings suggest that elderly consumers are concerned about how they appear to others when driving a hybrid car,” the researchers wrote. “They believe that driving a hybrid car builds a positive self-image of the people who drive them.””This knowledge can help as a marketing tool,” Yoo said. “Hybrid cars have increased in visibility because of their environmental consciousness. So people may be willing to pay an extra $5,000 or so in order to think, ‘I’m great, and this is good for the environment.'”Previous research has shown that older consumers are more inclined to behave in a pro-environment way than younger generations are, Yoo said.

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Scientists pinpoint proteins vital to long-term memory

Sep. 12, 2013 — Scientists from the Florida campus of The Scripps Research Institute (TSRI) have found a group of proteins essential to the formation of long-term memories.The study, published online ahead of print on September 12, 2013 by the journal Cell Reports, focuses on a family of proteins called Wnts. These proteins send signals from the outside to the inside of a cell, inducing a cellular response crucial for many aspects of embryonic development, including stem cell differentiation, as well as for normal functioning of the adult brain.”By removing the function of three proteins in the Wnt signaling pathway, we produced a deficit in long-term but not short-term memory,” said Ron Davis, chair of the TSRI Department of Neuroscience. “The pathway is clearly part of the conversion of short-term memory to the long-term stable form, which occurs through changes in gene expression.”The findings stem from experiments probing the role of Wnt signaling components in olfactory memory formation in Drosophila, the common fruit fly — a widely used doppelgänger for human memory studies. In the new study, the scientists inactivated the expression of several Wnt signaling proteins in the mushroom bodies of adult flies — part of the fly brain that plays a role in learning and memory.The resulting memory disruption, Davis said, suggests that Wnt signaling participates actively in the formation of long-term memory, rather than having some general, non-specific effect on behavior.”What is interesting is that the molecular mechanisms of adult memory use the same processes that guide the early development of the organism, except that they are repurposed for memory formation,” he said. “One difference, however, is that during early development the signals are intrinsic, while in adults they require an outside stimulus to create a memory.”The first author of the study, “Wnt signaling is required for long-term memory formation,” is Ying Tan of the Baylor College of Medicine. Other authors include Germain U. Busto of TSRI and Curtis Wilson of Baylor College of Medicine.The study was supported by the National Institutes of Health (NS19904).

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How smoking increases vulnerability to alcohol abuse

July 18, 2013 — Smoking is a well-known risk factor for subsequent alcohol abuse, but the mechanisms underlying this link are unknown. Now researchers reporting in the Cell Press journal Neuron on July 18 show in a study conducted in rats that even a single exposure to nicotine temporarily changes how the brain’s reward system responds to alcohol and increases the reinforcing properties of alcohol via stress hormones.Share This:”Our findings indicate the mechanisms by which nicotine influences the neural systems associated with alcohol abuse, providing a foundation for conceptualizing strategies aimed at diminishing the link between smoking and later alcohol abuse,” says senior author Dr. John Dani, of the Baylor College of Medicine.Dr. Dani and his team found that rats exposed to nicotine subsequently sought to drink alcohol more often than other rats. Also, signaling in the brain’s reward system was dampened when the nicotine-exposed animals consumed alcohol. This decreased reward response to alcohol arose via two mechanisms: an initial activation of stress hormone receptors and a subsequent increase in inhibitory signaling in the brain. These processes were responsible for causing the rats to self-administer more alcohol after nicotine exposure.”Young people typically experiment with nicotine from tobacco in their teens, and that exposure possibly contributes to a greater vulnerability to alcohol abuse later in life. Therefore, greater vigilance is called for to prevent the initial exposure to nicotine and to follow those at risk,” says Dr. Dani. “In addition, our work suggests that stress hormones are candidate targets for prevention or treatment therapies.”Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is reprinted from materials provided by Cell Press, via EurekAlert!, a service of AAAS. …

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‘Spiritual’ young people more likely to commit crimes than ‘religious’ ones

June 12, 2013 — Young adults who deem themselves “spiritual but not religious” are more likely to commit property crimes — and to a lesser extent, violent ones — than those who identify themselves as either “religious and spiritual” or “religious but not spiritual,” according to Baylor University researchers.The sociologists’ study, published in the journal Criminology, also showed that those in a fourth category — who say they are neither spiritual nor religious — are less likely to commit property crimes than the “spiritual but not religious” individuals. But no difference was found between the two groups when it came to violent crimes.”The notion of being spiritual but not associated with any organized religion has become increasingly popular, and our question is how that is different from being religious, whether you call yourself ‘spiritual’ or not,” said Sung Joon Jang, Ph.D., an associate professor of sociology in Baylor’s College of Arts & Sciences. He is lead author of the study, “Is Being ‘Spiritual’ Enough Without Being Religious? A Study of Violent and Property Crimes Among Emerging Adults.”He noted that until the 20th century, the terms “religious” and “spiritual” were treated as interchangeable.Previous research indicated that people who say they are religious show lower levels of crime and deviance, which refers to norm-violating behavior.The researchers analyzed data from a sample of 14,322 individuals from the National Longitudinal Study of Adolescent Health. They ranged in age from 18 to 28, with an average age of 21.8.In the confidential survey, participants were asked how often they had committed crimes in the previous 12 months — including violent crimes such as physical fights or armed robbery — while property crimes included vandalism, theft and burglary.Past research shows that people who report themselves as spiritual make up about 10 percent of the general population, Jang said.”Calling oneself ‘spiritual but not religious’ turned out to more of an antisocial characteristic, unlike identifying oneself as religious,” said Baylor researcher Aaron Franzen, a doctoral candidate and study co-author.In their study, the Baylor researchers hypothesized that those who are spiritual but not religious would be less conventional than the religious group — but could be either more or less conventional than the “neither” group.”We were thinking that religious people would have an institutional and communal attachment and investment, while the spiritual people would have more of an independent identity,” Franzen said.Theories for why religious people are less likely to commit crime are that they fear “supernatural sanctions” as well as criminal punishment and feel shame about deviance; are bonded to conventional society; exercise high self-control in part because of parents who also are likely to be religious; and associate with peers who reinforce their behavior and beliefs.Significantly, people who are spiritual but not religious tend to have lower self-control than those who are religious. They also are more likely to experience such strains as criminal victimization and such negative emotions as depression and anxiety. They also are more likely to have peers who use and abuse alcohol, Franzen said. Those factors are predictors of criminal behavior.”It’s a challenge in terms of research to know what that actually means to be spiritual, because they self-identify,” he said. “But they are different in some way, as our study shows.”In their research, sociologists included four categories based on how the young adults reported themselves. Those categories and percentages were:• Spiritual but not religious, 11.5 percent• Religious but not spiritual, 6.8 percent• Both spiritual and religious, 37.9 percent• Neither spiritual nor religious, 43.8 percent

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