RESEARCHERS VIEW THE "BIG PICTURE" OF GENE ACTIVITY
A new technique allows scientists to simultaneously visualize the activity of multiple genes in a single cell. University of California-San Diego biologists used bright fluorescent dyes to see the combination of genes that are active in a particular cell during development, a technique know as multiplex labeling. This makes it possible to quantify how active a gene is, as well as make inferences about the genetic make-up of an organism. "In addition to facilitating our own research on fruit fly development, there are many potential applications for this technique," said the lead researcher. "For example, it could be used to understand how tumors arise and grow, by revealing what genes are turned on and when. With this information, it should be possible for cancer biologists to predict how aggressive a tumor will be from its early patterns of gene expression." The technique is described in the August 6 issue of Science.
PRO-INFLAMMATORY GENE LINKED TO TUMOR DEVELOPMENT
A new study shows that the inactivation of a pro-inflammatory gene greatly reduces tumor development in mice. Investigators from the University of California-San Diego found that a gene called I-kappa-B kinase (IKK beta) acts differently in two cell types to cause cancer. When IKK beta was deleted, the cancer incidence and tumor growth in mice was decreased by nearly 80 percent. IKK beta is required for activation of a protein that acts as a master switch to turn on inflammation in response to bacterial or viral infections. This study offers the first evidence of a molecular link between inflammation and cancer, a link that has long been suspected. "We've shown how tumors arise from chronic infection and inflammation that act together with chemical carcinogens," said the study's senior author. The scientists used colitis associated cancer (CAC) as their model for study. CAC occurs in people suffering from chronic colitis. This research appears in the August 6 issue of the journal Cell.
GENE AIDS IN RECOVERY FROM HEPATITIS C
Scientists have discovered how some people infected with the liver disease hepatitis C 'self-recover'. Johns Hopkins researchers found that the genes for a key protein called KIR2DL3, in combination with genes for a molecule called HLA, were more common in patients who spontaneously recovered from hepatitis C. The researchers found the KIR2DL3-HLA link while studying the DNA analysis of blood samples from more than 1,000 patients infected with the disease. "Hepatitis C infection is a serious disease with few treatments, and it takes a heavy toll among disadvantaged Americans, including those who have weakened immune systems and are HIV positive," said one researcher. "Our results were surprising in that self-recovery is not so much a function of speeding up the body's immune system to attack the hepatitis C virus as it is about taking the foot off the brakes so the body's killer immune cells can take off." The researchers hope their finding will help to one day develop a vaccine and improve therapies for hepatitis C. These findings were published in the August 6 online edition of Science.
GENES MAY PLAY ROLE IN COCAINE ADDICTION
Two related genes involved in communication between brain cells may be sending a message that triggers cocaine addiction. Medical University of South Carolina researchers found that deleting either of two genes in the Homer family in mice produced the same symptoms seen in cocaine withdrawal. The researchers individually knocked out the genes in mutant mice and tested the biological and behavioral effects. In a behavioral test, the researchers placed the knockout mice in one of two linked chambers after cocaine administration - one a "comfortable" darkened chamber with nesting material and the other and "uncomfortable" bare, white, brightly lit chamber. Mice lacking the Homer1 or Homer2 genes showed greater preference for the chamber that they associated with receiving cocaine, as compared to normal controls. Homer2 knockout mice also showed a greater motivation to self-administer cocaine by pressing a lever. The knockout mice could be restored to normal by reintroduction of the Homer2 gene. The Homer genes appear to be specific for cocaine. This research appeared in the August 5 edition of Neuron.
18 ORGANISMS ADDED TO SEQUENCING PIPELINE
The National Human Genome Research Institute (NHGRI) announced that genetic sequencing would begin on 18 organisms. The organisms fall into two groups, the first consisting of nine mammals. The mammals include the African savannah elephant, the European common shrew, the European hedgehog, the guinea pig, the lesser hedgehog tenrec, the nine-banded armadillo, the rabbit, the domestic cat and the orangutan. The orangutan genome will be used in conjunction with the chimpanzee and rhesus macaque genomes to identify those features in the human genome that differ among primates. The second group is made up of nine non-mammalian organisms which represent different positions on the evolutionary timeline marked by important changes in animal anatomy, physiology, development or behavior. These organisms include a slime mold, a snail, two roundworms and the lamprey, among others. "With each new genome that we sequence, we move closer to the goal of finding all of the crucial elements of the human genome involved in development, health and disease," said one of the NHGRI directors. The NHGRI made this announcement on August 4.
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(Editors: For more information on TECHNIQUE, contact Sherry Seethaler at 858-534-4656 or [email protected]. For PRO-INFLAMMATORY, Sue Pondrom at 619-543-6163 or [email protected]. For SELF-RECOVERY, David March at 410-955-1534 or [email protected]. For COCAINE, Heidi Hardman at 617-397-2879 or [email protected]. For ORGANISMS, Geoff Spencer at 301-402-0911 or [email protected])
