Smoking is a well-known risk factor for lung cancer, but nearly 25% of all lung cancer patients have never smoked. In a study published online in Genome Research ( http://www.genome.org ), researchers have identified a previously unknown gene fusion event that could explain a significant proportion of lung cancer cases in never-smokers, and might serve as a target for new therapies. Recent strides have been made to identify gene mutation events driving cases of lung adenocarcinoma in never-smokers, but the underlying genetic events leading to these lung cancers still remain unknown in a large number of cases. In this report, using a combination of genome sequencing and RNA sequencing, a team of researchers in South Korea has characterized a previously unknown gene fusion event in a case of lung adenocarcinoma striking a 33-year-old Korean male with no history of smoking or cancer within his family.
Transcriptional Elongation Control Takes On New Dimensions As Stowers Researchers Find Gene Class-Specific Elongation Factors
Life is complicated enough, so you can forgive the pioneers of DNA biology for glossing over transcriptional elongation control by RNA polymerase II, the quick and seemingly bulletproof penultimate step in the process that copies the information encoded in our DNA into protein-making instructions carried by messenger RNA. In a new report appearing in the Dec. 23, 2011, issue of Molecular Cell, researchers at the Stowers Institute for Medical Research add not just a new layer, but a whole new dimension to transcriptional elongation control with evidence that for each class of genes transcribed by RNA polymerase II (Pol II), there exists a specific class of elongation factors. The Stowers team, led by investigator Ali Shilatifard, Ph.D., discovered that ELL, short for eleven-nineteen lysine-rich leukemia, not only belongs to an assemblage of transcription elongation factors, which Shilatifard's lab had identified as the "Super Elongation Complex" (SEC) a few years ago, but also that ELL is part of a distinct "Little Elongation Complex" (LEC), which acts on a completely different class of genes transcribed by Pol II.
Mutations in the ATM gene may increase the hereditary risk for pancreatic cancer, according to data published in Cancer Discovery, the newest journal of the American Association for Cancer Research. Pancreatic cancer is one of the most morbid cancers, with less than 5 percent of those diagnosed with the disease surviving to five years. Approximately 10 percent of patients come from families with multiple cases of pancreatic cancer. "There was significant reason to believe this clustering was due to genetics, but we had not, to this point, been able to find the causative genes that explained the cluster of pancreatic cancer for a majority of these families, " said lead author Alison Klein, Ph.D., associate professor of oncology at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins and director of the National Familial Pancreas Tumor Registry.
An international team of scientists, led by researchers at the University of California, San Diego School of Medicine, reports that abnormal sequences of DNA known as rare copy number variants, or CNVs, appear to play a significant role in the risk for early onset bipolar disorder. The findings were published in the Dec. 22 issue of the journal Neuron. CNVs are genomic alterations in which there are too few or too many copies of sections of DNA. Researchers have known that spontaneously occurring (de novo) CNVs - genetic mutations not inherited from parents - significantly increase the risk for some neuropsychiatric conditions, such as schizophrenia or the autism spectrum disorders. But their role was unclear in bipolar disorder, previously known as manic depression. Principal investigator Jonathan Sebat, PhD, assistant professor of psychiatry and cellular and molecular medicine at UC San Diego's Institute of Genomic Medicine, and colleagues, found that de novo CNVs contribute significant genetic risk in about 5 percent of early onset bipolar disorder, which appears in childhood or early adulthood.
Small, mobile sequences of DNA left over from viruses, called transposons or "jumping genes" because of their ability to move around the genome, pose a significant threat to the genetic integrity and stability of an organism. Considered genetic parasites, these transposable elements are believed to comprise as much as 50 percent of the human genome. Because of the damage transposons can do to an organism's DNA, an immune-like response has evolved to turn off, or silence, these mobile genetic elements. New research published in the journal Cell by the labs of William E. Theurkauf and Zhiping Weng at the University of Massachusetts Medical School sheds light on how the genome defends itself from these invading DNA parasites. While it's known that specific small RNAs called Piwi-interacting RNAs (piRNAs) are responsible for silencing transposons, how this biologically critical system reacts to the introduction of a new transposon isn't fully understood.