Genetic test closer for testicular cancer; parabens dangerous even at low doses
Study adds to evidence that testicular cancer is highly likely to be passed down from father
A new study of more than 25,000 men has uncovered four new genetic variants associated with increased risk of testicular cancer, bringing the total number of genetic variants known to be associated with testicular cancer to 25. "Applying these 25 variants, we found that men in the top 1 per cent for testicular cancer risk were at a more than tenfold elevated risk of developing the disease compared with the average - although that still adds up to only around a 5 per cent chance of developing testicular cancer," says Dr Clare Turnbull, who conducted the study with colleagues at the Institute of Cancer Research, London. "In the future, if we can identify more of the genetic variation underlying testicular cancer, this sort of testing might be used to help identify those at most risk of testicular cancer before they develop the disease, such that we can offer measures to help stop them from developing it." Professor Paul Workman, the institute's chief executive, says the study also adds detail to the emerging picture of testicular cancer as a strongly heritable disease and provides some evidence that genetic screening in selected groups of men could be a long-term possibility.
Estrogen-mimicking chemicals called parabens, which are commonly found in an array of personal care products such as shampoos and cosmetics, may be more dangerous at lower doses than previously thought, according to a new study. This may have implications for the development of breast cancer and other diseases that are influenced by estrogens, say the researchers from University of California, Berkeley. The study looked at breast cancer cells that expressed estrogen receptors and human epidermal growth factor receptor 2 (HER2). HER2-positive tumours - seen in about a quarter of breast cancer cases - tend to grow and spread more aggressively than other types of breast cancer. The researchers activated the HER2 receptors in breast cancer cells with a growth factor called heregulin that is naturally made in breast cells, while exposing the cells to parabens. Not only did the parabens trigger the estrogen receptors by turning on genes that caused the cells to proliferate, the effect was significant: the parabens in the HER2-activated cells were able to stimulate breast cancer cell growth at concentrations 100 times lower than in cells that were deprived of heregulin.
While adults who take in more morning light are slimmer, a new study by Queensland University of Technology's Sleep in Early Childhood Research Group finds the opposite true in young children. Pre-schoolers exposed to more light earlier in the day tend to weigh more, the researchers found. They suggest that light should be added now to the risk factors that have an impact on obesity, which presently include calorie intake, decreased physical activity, short sleep duration, and variable sleep timing. In the study, 48 children aged three to five from six Brisbane childcare centres were tracked for two weeks, with their sleep, activity and light exposure measured along with their height and weight to calculate their body mass index. Children who received their biggest dose of light in the afternoon - outdoors and indoors - were found to be slimmer than children who had moderate intensity light exposure earlier in the day. "Surprisingly, physical activity was not associated with the body mass of the children but sleep timing and light exposure was," says researcher Cassandra Pattinson.
