A Canadian team led by Wan L Lam and Stephen Lam from the BC Cancer Agency, took samples from the lungs of 24 current and former smokers, as well as from non-smokers who have never smoked. They used these lung samples to create libraries using a technique called serial analysis of gene expression (SAGE), which helps to identify patterns of gene activity.
Only about a fifth of the genes in a cell are switched on at any given time, but environmental changes such as smoking lead to changes in gene activity. The researchers found changes that were irreversible, and some changes that were reversed by stopping smoking. The reversible genes were particularly involved in xenobiotic functions (managing chemicals not produced in the body), nucleotide metabolism and mucus secretion. Some DNA repair genes are irreversibly damaged by smoking, and smoking also switched off genes that help combat lung cancer development.
The researchers identified a number of genes not previously associated with smoking that are switched on in active smokers. One example is CABYR, a gene involved in helping sperm to swim and associated with brain tumours, which may have a ciliary function. The team also further investigated changes in genes involved in airway repair and regeneration, and within this group identified genes that fell into three categories following cessation of smoking: reversible (TFF3, encoding a structural component of mucus; CABYR, in it's newly discovered bronchial role), partially reversible (MUC5AC, a mucin gene) and irreversible (GSK3B, involved in COX2 regulation). These findings were tested against a second cohort of current, former and non-smokers.
"Those genes and functions which do not revert to normal levels upon smoking cessation may provide insight into why former smokers still maintain a risk of developing lung cancer," according to Raj Chari, first author of the study. The study is the largest human SAGE study reported to date, and also generated a large SAGE library for future research.
Tobacco smoking accounts for 85 percent of lung cancers, and former smokers account for half of those newly diagnosed with the disease.
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25.09.2017 | University of Maryland
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
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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