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:6/26/2016)... , ... June 27, 2016 , ... Quality metrics are ... in many ways they remain in the eye of the beholder, according to experts ... publication of The American Journal of Managed Care. For the full issue, click ...
(Date:6/26/2016)... Viejo, California (PRWEB) , ... June 26, 2016 , ... ... Final Cut Pro X. , "Film editors can give their videos a whole new ... said Christina Austin - CEO of Pixel Film Studios. , ProSlice Levels contains ...
(Date:6/26/2016)... Charlotte, NC (PRWEB) , ... June 26, 2016 , ... Brent Kasmer, a legally blind ... able to be personalized through a fitness app. The fitness app plans to fix the ... solutions currently only offer a one size fits all type program , They ...
(Date:6/25/2016)... ... 2016 , ... Experts from the American Institutes for Research ... June 26-28, 2016, at the Hynes Convention Center in Boston. , AIR experts ... planning, healthcare costs and patient and family engagement. , AIR researchers will be ...
(Date:6/25/2016)... , ... June 25, 2016 , ... The temporary closing of Bruton Memorial Library on ... Observer , brings up a new, often overlooked aspect of head lice: the parasite’s ability ... fumigation is not a common occurrence, but a necessary one in the event that lice ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... 2016 Research and Markets has announced ... Diagnostic Tests" report to their offering. ... The World Market for Companion Diagnostics covers ... Market analysis in the report includes the following: ... Diagnostic Kits) by Region (N. America, EU, ROW), 2015-2020 ...
(Date:6/24/2016)... Tenn. , June 24, 2016  Arkis ... providing less invasive and more durable cerebrospinal fluid ... in funding.  The Series-A funding is led by ... Lighthouse Fund, and other private investors.  Arkis, new ... neurosurgical instrumentation and the market release of its ...
(Date:6/23/2016)... Research and Markets has announced ... Type (Organic Chemical (Sugar, Petrochemical, Glycerin), Inorganic Chemical), Functionality ... - Global Forecast to 2021" report to their ... global pharmaceutical excipients market is projected to reach USD ... in the forecast period 2016 to 2021. ...
Breaking Medicine Technology: