Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

COX-2 levels are elevated in smokers

17.01.2005


Tobacco smoke triggers the production of COX-2, a cellular protein linked to the development and progression of cancer, according to research published in the January 15 issue of the journal Cancer Research.



Tobacco smoke also promoted rapid cellular production of two proteins that initiate an epidermal growth factor receptor (EGFR) driven cascade leading to the production of COX-2, the report stated.

The report by Andrew J. Dannenberg, M.D., director of cancer prevention, Weill Medical College of Cornell University, and colleagues, indicates that smokers produce as much as four times the amount of COX-2 in oral mucosal cells lining their mouths than their non-smoking counterparts.


After observing the increased amount of COX-2 in the oral mucosa of smokers, Dannenberg and his team of collaborating scientists exposed cells in culture to tobacco smoke to define the mechanism underlying smoke-induced elevation of COX-2.

The researchers determined that COX-2 levels were increased due to tobacco smoke induced activation of EGFR, a cell membrane protein also associated with various types of cancer. Tobacco smoke stimulated the oral mucosal cells to rapidly release two proteins that activate the EGFR, initiating a cascade resulting in COX-2 protein production. "In an oral mucosal cell line, tobacco smoke clearly activated the epidermal growth factor receptor. Tobacco smoke caused increased EGFR phosphorylation leading to increased COX-2 production," Dannenberg reported.

"We were able to block the induction of COX-2 with either a small molecule that inhibited EGFR activity or an antibody that prevented ligands from binding to and activating the EGFR. These findings led us to question whether tobacco smoke initiated the process of increasing COX-2 production by first stimulating production of proteins that controlled activity of the EGF receptor," Dannenberg said.

Cells exposed to tobacco smoke increased production of two EGFR ligands, or proteins that bind to and activate the growth factor receptor. Tobacco smoke exposed oral mucosal cells produced more amphiregulin and TGF-alpha, both of which trigger EGFR function. "Cellular release of both of these EGFR ligands occurred quickly after exposure to tobacco smoke," Dannenberg said. These findings appear to be directly relevant to people because increased levels of both proteins were also detected in oral biopsies from smokers. "These results provide new insights into the mechanism by which tobacco smoke causes cancer. Mutations can only occur in proliferating cells and activation of EGFR signaling enhances cell proliferation," Dannenberg said. "These results strengthen the rational for targeting not only COX-2, but also EGFR as approaches for reducing the risk of tobacco-related malignancies of the mouth and throat," Dannenberg said.

Dannenberg investigated the mechanism of tobacco smoke effects on oral mucosa with team of scientists including Dimitrios Moraitis, M.D., Jay O. Boyle, M.D., and Erik G. Cohen, M.D., Memorial Sloan-Kettering Cancer Center, New York, N.Y; Baoheng Du, M.D., Mariana S. De Lorenzo, Ph.D., Babette B. Weksler, M.D., Kotha Subbaramaiah, Ph.D., John F. Carew, M.D., and Nasser K. Altorki, M.D., Weil Medical College of Cornell University, New York, N.Y.; and Levy Kopelovich, Ph.D., National Cancer Institute, Bethesda, M.D.

Russell Vanderboom, Ph.D | EurekAlert!
Further information:
http://www.aacr.org

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>