Navigation Links
A new way to look at lung cancer and tobacco carcinogens
Date:5/28/2008

PHILADELPHIA Two types of cancer-causing agents in cigarettesa nicotine-derived chemical and polycyclic aromatic hydrocarbons (PAHs) are the main culprits in lung cancer. Exposure to tobacco smoke both mainstream and second-hand is a leading cause of cancer death in the United States.

Previous studies have shown how PAHs damage DNA, with the emphasis on how PAHs bind directly to DNA itself, leading to the mutations in critical genes that cause disease. Now, researchers at the University of Pennsylvanias School of Medicines Center of Excellence in Environmental Toxicology (CEET) have shown that PAHs, via oxidative stress, can also led to mutations in critical genes important in lung cancer. The findings were published online last week in the Proceedings of the National Academy of Sciences.

This is the first demonstration of this link, says co-author Ian Blair, PhD, Professor and Vice Chair of the Department of Pharmacology . This is a second, but indirect, way in which PAHs can cause cancer. We also know that PAHs can also cause cancer directly.

Several genetic studies have also shown that the enzymes responsible for generating the oxidative stress from PAHs are overexpressed in lung cancer tumor tissue and esophageal cancers, explains Trevor Penning, PhD, CEETs director and the studys senior author. Our study also shows that those same enzymes, called AKRs, are responsible for the oxidative stress from PAHs in the human lung cells we used in our experiments.

Oxidative stress is the accumulation of destructive molecules called free radicals that can lead to cell death. Free radicals damage cell membranes, proteins, or genetic material by oxidizing them, the same way oxygen causes iron to rust.

The AKR enzymes transform PAHs to produce oxygen free radicals. These oxygen radicals bind to DNA, and if this damage is not repaired it leads to mutations that are carried through to the next generation of cells.

Penning also mentions another genetic ramification due to this association. A recent microarray study of all 30,000 human genes asked what genes were most over-expressed in non-small cell lung carcinoma. Of the eight genes that were most abundantly overexpressed, two were AKR enzymes.

Because this study relates AKR overexpression to oxidative damage of DNA with lung cancer, it makes you wonder if the 10 percent of smokers that are most prone to lung cancer, have either dysregulated AKR expression or genetic differences in their AKRs that predispose them to disease, says Penning. Since oxidative stress is also linked to tumor promotion, it is possible that his link may also explain other stages of the disease process.

These findings go beyond the first step of DNA damage and may provide a reason why disease progresses, says Penning.


'/>"/>

Contact: Karen Kreeger
karen.kreeger@uphs.upenn.edu
215-349-5658
University of Pennsylvania School of Medicine
Source:Eurekalert  

Related medicine news :

1. Conventional prognostic factors fail to explain better prostate cancer survival in most Asian men
2. Survival differences by race most apparent in advanced stages of breast cancer
3. MRI finds breast cancer before it becomes dangerous
4. Investigators uncover intriguing clues to why persistent acid reflux sometimes turns into cancer
5. Pathway links inflammation, angiogenesis and breast cancer
6. Radiologists encouraged to look beyond cancer for clinically unseen diseases
7. Diet high in meat, fat and refined grains linked to risk for colon cancer recurrence, death
8. Immune deficiency linked to a type of eye cancer
9. Drop in breast cancer incidence linked to hormone use, not mammograms
10. Breast cancer prevention practices vary across Canada
11. First biomarker discovered that predicts prostate cancer outcome
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
A new way to look at lung cancer and tobacco carcinogens
(Date:5/5/2016)... ... May 05, 2016 , ... Linfield College Online and Continuing Education is encouraging ... the $50 application fee for all qualified applicants from May 1–14. Students need only ... when applying . , With the RN to BSN degree ...
(Date:5/5/2016)... ... 2016 , ... In an effort to increase public awareness ... promotion and research organization, declared May as “National Sunshine Month.” , With ... cultural behavior over the past several decades, Americans spend more time indoors than ...
(Date:5/4/2016)... ... May 05, 2016 , ... The talus is the ... injuries like falls, or traffic accidents can cause the talus bone to be fractured, ... the bone. In a first-of-its-kind procedure using 3D printing technology, internationally renowned orthopedic surgeon ...
(Date:5/4/2016)... ... 04, 2016 , ... The manufacturer of the SOCKIT wearable ... to St. Jude Children’s Research Hospital to benefit families dealing with cancer and ... to teach children how to kick a soccer ball correctly. The device instantly ...
(Date:5/4/2016)... WA (PRWEB) , ... May ... ... a full service insurance provider serving families of Camas and Vancouver, WA, ... current campaign fundraises for the National Breast Cancer Foundation and their Mammography ...
Breaking Medicine News(10 mins):
(Date:5/3/2016)... May 3, 2016   Diplomat Pharmacy, Inc. (NYSE: DPLO) announced today that it is celebrating ... video of two patients who tell their personal story and encourage those at risk to ... Meet Jacque: Hepatitis C ... ... Diplomat Specialty Pharmacy (PRNewsFoto/Diplomat Pharmacy, Inc.) ...
(Date:5/3/2016)... YORK , May 3, 2016 ... (MRI) Market Size, Share, Development, Growth and Demand Forecast ... Open), by Field Strength (High Field, Very High Field, ... Application (Brain, Head and Neck, Spine, Musculoskeletal, Vascular, Breast, ... the global magnetic resonance imaging (MRI) market was valued ...
(Date:5/3/2016)... 3, 2016 Intec Pharma Ltd. ... biopharmaceutical company, today announced the appointment of Pnina ... "Ms. Strauss-Levy has 15 years of experience ... an outstanding track record, having supported the advancement of ... processes in the United States ...
Breaking Medicine Technology: