Researchers uncover potential mechanisms to protect against genetic alterations, diseasesAugust 07, 2009Peering into the DNA of tiny yeast, researchers at the Moores Cancer Center at the University of California, San Diego and the San Diego Branch of the Ludwig Institute for Cancer Research have pinpointed a large number of genes that can prevent a type of genetic rearrangement that may lead to cancer and other diseases. The presence of these genes and their accompanying pathways, many of which are involved in repairing mistakes in DNA replication, may help explain how the body fends off so many potentially damaging genetic alterations while maintaining its stability. "We've begun to identify the pathways that are very specific for preventing those types of rearrangements that involve DNA with duplications," said Richard Kolodner, PhD, professor of medicine and cellular and molecular medicine at the UC San Diego School of Medicine and the Moores UCSD Cancer Center, and a member of the San Diego Branch of the Ludwig Institute for Cancer Research (LICR). Reporting online in advance of publication in the August 20, 2009 issue of the journal Nature, Kolodner and his team focused on a particular type of genetic change called a Gross Chromosomal Rearrangement (GCR), a large-scale change in the structures of chromosomes, which house genes. Such changes might entail a sequence of genes being deleted or genetic material exchanging positions on chromosomes. According to Kolodner, while the human genome contains many regions where rearrangements, genetic duplications and other aberrations are more likely to occur - increasing the likelihood for chromosomal mistakes and genetic mutations - the genome is surprisingly stable. To try to better understand why, the researchers examined GCR formation in chromosome regions in yeast (Saccharomyces cerevisiae). Using a modified version of a previously developed test, they compared the rate and features of GCR formation in a chromosome region lacking "at-risk" DNA sequences with that of a region containing DNA duplications, which are more likely to drive rearrangements. These latter regions were much more like human chromosomes. More importantly, they also looked at the effects of various genes and pathways on the development of GCRs. The research team found that many genes and genetic pathways that failed to block GCR formation in "lower-risk" regions actually played a large role in suppressing GCRs in "at-risk" areas. "This work points out that there are many different and unexpected pathways that specifically prevent duplication-mediated rearrangements," said Christopher Putnam, PhD, adjunct assistant professor of medicine at the UC San Diego School of Medicine and assistant investigator at the LICR San Diego Branch. "All of these new pathways are important candidates for novel tumor suppressor genes and could be involved in cancer progression. They might also suggest novel therapeutic treatments." "Because of the wide range of ways for an individual's genome to become unstable and for genetic mutations to occur, it has always been somewhat of a mystery why genetic mutations and genomic instability don't happen more frequently," Kolodner said. "This is the first time we've identified pathways that can prevent GCRs mediated by at-risk sequences from happening." Kolodner added that - if it can be shown that these genes are mutated in cancer - it gives reasons to target them, since genetic defects are most often found in repair pathways. "But we need to find out which are the right genes." The list of genes and pathways is extensive, and will likely be much longer, Kolodner said, predicting that the list in humans will be 500 to 1,000 genes, and in yeast, closer to 500. University of California - San Diego |
|||||||||||||||||||||
| Related Genes Current Events and Genes News Articles Time of day matters to thirsty trees, U of T researcher discovers The time of day matters to forest trees dealing with drought, according to a new paper produced by a research team led by Professor Malcolm Campbell, University of Toronto Scarborough's vice-principal for research and colleagues in the department of cell and systems biology at the St. George campus. Delft breakthrough in bioethanol production from agricultural waste With the introduction of a single bacterial gene into yeast, researchers from Delft University of Technology in the Netherlands achieved three improvements in bioethanol production from agricultural waste material: 'More ethanol, less acetate and elimination of the major by-product glycerol' This week the invention was published in the scientific journal Applied and Environmental Microbiology. Researchers Identify Role of Gene in Tumor Development, Growth and Progression Virginia Commonwealth University Massey Cancer Center and VCU Institute of Molecular Medicine researchers have identified a gene that may play a pivotal role in two processes that are essential for tumor development, growth and progression to metastasis. Genetic analysis helps dissect molecular basis of cardiovascular disease Using highly precise measurements of plasma lipoprotein concentrations determined by nuclear magnetic resonance spectroscopy (NMR), researchers led by Daniel Chasman at Brigham and Women's Hospital and Harvard Medical School in Boston, MA, the Framingham Heart Study in Framingham, and the PROCARDIS consortium in Stockholm, Sweden and Oxford, England performed genetic association analysis across the whole genome among 17,296 women of European ancestry from the Women's Genome Health Study. It's a gas: New discovery may lead to heartier, high-yielding plants In a research report published in the November 2009 issue of the journal GENETICS, scientists show how a family of genes (1-aminocyclopropane-1-carboxylate synthase, or ACS genes) are responsible for production of ethylene. Gene mismatch influences success of bone marrow transplants A commonly inherited gene deletion can increase the likelihood of immune complications following bone marrow transplantation, an international team of researchers reports in the November 22 advance online issue of Nature Genetics. Cancer metabolism discovery uncovers new role of IDH1 gene mutation in brain cancer Agios Pharmaceuticals today announced that its scientists have established, for the first time, that the mutated IDH1 gene has a novel enzyme activity consistent with a cancer-causing gene, or oncogene. Scientists at UA, collaborating institutions decode maize genome Scientists from the University of Arizona led by Arizona Genomics Institute director Rod A. Wing and from collaborating institutions have deciphered the complete genetic code of the maize plant for the first time. Schizophrenia gene's role may be broader, more potent, than thought UCSF scientists studying nerve cells in fruit flies have uncovered a new function for a gene whose human equivalent may play a critical role in schizophrenia. Ancestry attracts, but love is blind People preferentially marry those with similar ancestry, but their decisions are not necessarily based on hair, eye or skin colour. More Genes Current Events and Genes News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||