Featured Research

from universities, journals, and other organizations

Carcinogen In Cigarettes Causes Mutation Linked To Lung Cancer

Date:
October 17, 2002
Source:
New York University Medical Center
Summary:
NYU School of Medicine researchers report that a chemical in cigarette smoke causes mutations in a gene called RAS that are commonly associated with many human cancers, according to a new study. The study provides a direct molecular link between smoking and lung cancer, and the technique used in the study should help identify other environmental chemicals that contribute to human cancers, says Eric Moon-shong Tang, Ph.D., Professor of Environmental Medicine, who led the study.

NYU School of Medicine researchers report that a chemical in cigarette smoke causes mutations in a gene called RAS that are commonly associated with many human cancers, according to a new study. The study provides a direct molecular link between smoking and lung cancer, and the technique used in the study should help identify other environmental chemicals that contribute to human cancers, says Eric Moon-shong Tang, Ph.D., Professor of Environmental Medicine, who led the study.

This is the second report by Dr. Tang directly linking a chemical in cigarette smoke to mutations in a crucial gene associated with cancer. In 1996, he published a study in the journal Science showing that a carcinogen found in cigarette smoke caused mutations in a gene called P53.

The new study is published in the October 16 issue of the Journal of the National Cancer Institute.

"With this new study, we are now providing concrete proof that smoking causes lung cancer," says Dr. Tang.

RAS is a family of genes that have many biological functions, but mainly control cell growth and development. Mutations in a RAS gene can lead to uncontrolled cell growth, and more than 30 percent of lung cancers, 90 percent of pancreatic cancers, and 50 percent of colon cancers are associated with mutations at a specific site in the gene K-RAS.

Scientists, however, didn't know why these mutations were occurring at this particular site in the gene. The new study provides an answer to this longstanding question by using a mapping technique that Dr. Tang pioneered. The technique pinpoints the exact sites on DNA where damage occurs due to environmental carcinogens.

Dr. Tang and colleagues from NYU and M.D. Anderson Cancer Center, in Houston, introduced the carcinogen benzo(a)pyrene diol expoxide (BPDE), a known cancer-causing chemical in cigarette smoke, to normal human lung epithelial cells and fibroblasts, another type of cell. Then they observed the effects of the chemical using their mapping technique. They found that the carcinogen preferentially bound to the K-RAS gene at a mutational hot-spot called codon 12, an area especially vulnerable to mutation. Moreover, the researchers found that this site was not able to repair itself very well. The chemical did not bind significantly to other members of the RAS gene family.

Genes comprise codons, sequences of three chemicals that spell out the code for amino acids, the building blocks of proteins. The mapping technique relies in part on special enzymes that cut DNA where it has been damaged by the binding of a carcinogen, which is technically called a DNA adduct. Adducts cause mutations in codons.

Dr. Tang says that the study's findings provide further proof that smoking does cause lung cancer because the carcinogen bound most strongly to the precise site in the K-RAS gene that is frequently mutated in lung cancer. Using the same mapping technique, he says it may be possible to discover the environmental agent or agents that are causing the gene to mutate in pancreatic cancer, which is far more commonly associated with a codon 12 mutation than is lung cancer.

"If we could identify the agents that are causing the mutations, then we might be able to design effective measures to prevent this type of cancer," says Dr. Tang.

In the future, Dr. Tang hopes to identify the mechanisms that make the codon in the K-RAS gene more susceptible to damage. He also plans to explore the possibility that there may be individual differences in susceptibility to damage at this site, meaning that some people may be more prone to certain types of cancer.

In an editorial accompanying the study in the same issue of the Journal of the National Cancer Institute, researchers Michael J. Kelley and Susan J. Littman of Duke University Medical Center, Durham, NC, write: "...[U]nderstanding the biologic basis for frequent mutations at codon 12 of K-ras in carcinomas may identify subtle but clinically significant differences in biochemical signaling pathways that can potentially be therapeutically targeted."

Dr. Tang's co-authors on the study are: Zhaohui Feng, Wenwei Hu, James X. Chen, Haiying Li, and William Rom, from NYU School of Medicine; and Annie Pao, Mien-Chie Hung from M.D. Anderson Cancer Center.

The study was supported by grants from the Public Health Service, the National Institute of Environmental Health Sciences, and the National Cancer Institute.


Story Source:

The above story is based on materials provided by New York University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

New York University Medical Center. "Carcinogen In Cigarettes Causes Mutation Linked To Lung Cancer." ScienceDaily. ScienceDaily, 17 October 2002. <www.sciencedaily.com/releases/2002/10/021017070113.htm>.
New York University Medical Center. (2002, October 17). Carcinogen In Cigarettes Causes Mutation Linked To Lung Cancer. ScienceDaily. Retrieved August 29, 2014 from www.sciencedaily.com/releases/2002/10/021017070113.htm
New York University Medical Center. "Carcinogen In Cigarettes Causes Mutation Linked To Lung Cancer." ScienceDaily. www.sciencedaily.com/releases/2002/10/021017070113.htm (accessed August 29, 2014).

Share This




More Health & Medicine News

Friday, August 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Who Could Be Burnt by WHO's E-Cigs Move?

Who Could Be Burnt by WHO's E-Cigs Move?

Reuters - Business Video Online (Aug. 28, 2014) The World Health Organisation has called for the regulation of electronic cigarettes as both tobacco and medical products. Ciara Lee looks at the impact of the move on the tobacco industry. Video provided by Reuters
Powered by NewsLook.com
CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

Newsy (Aug. 28, 2014) CDC director Tom Frieden says the Ebola outbreak is even worse than he feared. But he also said there's still hope to contain it. Video provided by Newsy
Powered by NewsLook.com
How A 'Rule Of Thumb' Could Slow Down Drinking

How A 'Rule Of Thumb' Could Slow Down Drinking

Newsy (Aug. 28, 2014) A study suggests people who follow a "rule of thumb" when pouring wine dispense less than those who don't have a particular amount in mind. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins