In experiments with mice, a team of scientists from the United States, Sweden and Japan has discovered that having a double dose of one protein is sufficient to change the normal balance of cells within the lining of the colon, thereby doubling the risk that a cancer-causing genetic mutation will trigger a tumor there. Roughly 10 percent of people have this double protein dose as well.
In the Feb. 24 online version of Science, the researchers report that mice engineered to have a double dose of insulin-like growth factor 2 (IGF2) develop more so-called precursor cells within the lining of the colon than normal mice. When these mice also carried a colon-cancer-causing genetic mutation, they developed twice as many tumors as those with normal IGF2 levels, the researchers report. "Both clinically and scientifically, this discovery should expand attention in colon cancer research to earlier events, situations present well before tumors appear," says the studys leader, Andrew Feinberg, M.D., M.P.H., professor of medicine and director of the Center for Epigenetics in Common Human Disease at Johns Hopkins. "In the mice with a double dose of IGF2, everything is pretty normal except for the extra precursor cells," says Christine Iacobuzio-Donahue, M.D., assistant professor of pathology and oncology. "But when the genetic mutation is present, too, we found a clear cost for what otherwise appears to be a benign effect of extra IGF2."
The teams analysis of colon tissue samples from a dozen or so Johns Hopkins patients with suspected colon cancer suggests that IGF2s effect in people may be similar, the researchers report. A larger study of samples from patients with and without suspected colon cancer is underway, Feinberg notes. In the mice -- as well as in about 30 percent of colon cancer patients and 10 percent of the general population -- the extra IGF2 stems not from a genetic problem, or mutation, but an "epigenetic" problem that improperly turns on the copy of the IGF2 gene that should remain off. Unlike most genes, the copy of IGF2 that should be silent depends only on which parent it came from, a situation called genomic imprinting. For IGF2, the copy inherited from the mother is always supposed to be turned off.
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At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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