New Gene Discoveries Hint at Brain Cancer Treatments
Scientists have long known that cancer results from an accumulation of genetic damage. But despite decades of research, the list of known cancer-related genes is surprisingly short. Equipped with powerful new technology, scientists recently began casting a wide net for genes involved in brain cancer. In an NIH-funded study published in Science, a team based at Johns Hopkins University found dozens of genes associated with an aggressive form of brain cancer called glioblastoma multiforme (GBM). “This study is a goldmine for potential new therapies,” says study coauthor Dr. Gregory Riggins of Johns Hopkins. The study was funded in part by NINDS and NCI.
Riggins and colleagues acquired DNA from the tumors of 22 GBM patients and scanned nearly the entire set of human genes for mutations (misspellings within the DNA code) and for copy number variations or CNVs (duplications or deletions of an entire gene). They scanned a smaller set of genes from an additional 83 GBM samples.
They found that 42 genes harbored mutations or CNVs that were significantly associated with GBM. Many of these genes were known offenders with roles in cellular growth, division and DNA repair, all of which are pathways one would expect to go awry in a cell that is proliferating unchecked. Somewhat unexpected was the finding that single tumors tended to have multiple gene defects affecting all three pathways.
The Cancer Genome Atlas, a project sponsored by NCI and the National Human Genome Research Institute, found similar results, as reported in Nature. Those findings are helping reshape ideas about treatments for GBM. Ongoing clinical studies have focused on single drug therapies aimed at single pathways, but researchers may need to start testing drug cocktails meant to target several different pathways at once, Riggins says.
Swimming Lessons Do Not Increase Drowning Risk in Young Children
|Providing very young children with swimming lessons appears to have a protective effect against drowning and does not increase children’s risk of drowning, according to an NICHD study.
Providing very young children with swimming lessons appears to have a protective effect against drowning and does not increase children’s risk of drowning, according to an NICHD study published in the March Archives of Pediatrics and Adolescent Medicine. Researchers said the findings should ease concerns among health professionals that giving swimming lessons to children from ages 1 to 4 years might indirectly increase drowning risk by making parents and caregivers less vigilant when children are near bodies of water.
To conduct the study, researchers analyzed medical examiner and coroner records and interviewed families of children who drowned. The children ranged from ages 1 to 19. The researchers compared characteristics of each child who drowned to another child of the same sex and age who did not drown and who lived in the same geographic area. Of the 61 1-4 year olds who drowned, 2 (3 percent) had received swimming lessons. In contrast, 35 of the 134 children who did not drown (26 percent) had taken swimming lessons. Study lead author Dr. Ruth Brenner said that the statistical methods she and her coauthors used to interpret the data suggest that swimming lessons provided some protection against drowning. It was not possible to calculate the exact extent of that protective effect.
Molecule Provides Clues About How HPV
Infection May Lead to Cancer
INew research shows for the first time that certain types of human papillomavirus (HPV), which cause cervical and some other types of cancer, can inhibit the production of a tiny single-stranded RNA called microRNA 34a, or miR-34a. Because previous research had shown that microRNAs regulate important functions of the cell, the new finding provides insight into the mechanisms by which HPV contributes to the development of cancer. These clues may point to treatments to counter HPV infection. Currently, such treatments do not exist. The study, online Mar. 3 and in the April print edition of the journal RNA, was led by NCI researchers. HPV inhibits natural tumor suppression by inactivating a cellular tumor suppressor protein called p53. P53 regulates expression of other genes that control the cell cycle, activates repair of damaged DNA in cells and—in cases of severe damage—initiates cell death. This protein also stimulates the expression of a group of microRNAs, including miR-34a.—