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

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>