NOV 10, 2016 11:36 AM PST

Scientists Quantify Smoking Damage in Cancer Genomes

WRITTEN BY: Xuan Pham

Scientists from the Los Alamos National Laboratory hope to squash any preconceived notions that the occasional cigarette is harmless. In their new study, the researchers finally quantified the amount of DNA damage caused by smoking, cigarette per cigarette - and the results are sombering.

Smoking and DNA mutations, the exact numbers are in | Image: pixabay.com
They found that a new mutation appears for every 50 cigarettes smoked. While that number seems innocent, think about how fast people smoke through a single cigarette before needing to light up another. Over the course of a year, a one-pack-a-day smoker can rack up as much as 150 mutations per lung cell alone. Mutations also pile on in other tissues exposed to the cigarette – the team estimated 97 mutations per larynx cell, 23 mutations per mouth cell, 18 mutations per bladder cell, and 6 mutations per liver cell.
           
Furthermore, cellular mutations can compound upon one another. This means a mutation that activates a cancer-promoting gene may influence mutations of other cancer genes. And if these mutations are maintained through cell division, it’s not hard to imagine an environment ripe for cancer to grow.
           
“Smoking is like playing Russian roulette: the more you play, the higher the chance the mutations will hit the right genes and you will develop cancer,” said Ludmil Alexandrov, the study’s co-lead author. “However, there will always be people who smoke a lot but the mutations do not hit the right genes.”
 


These results follow suit with a slew of recent evidence to highlight the molecular danger of smoking. Most recently, another study found that DNA damages caused by smoking can linger in a person’s genome for over 30 years, even after quitting. Taken together, we can conclude from the two studies that for every 50 cigarettes smoked, the genome acquires a new DNA mutation that may persist for decades in our body.
 
This isn’t to say that there’s no hope for smokers. In fact, it’s quite the opposite. The researchers hope that putting a concrete number for DNA damages associated with cigarettes will help smokers reduce and even quit their habit.
 
“Many smokers believe there’s no point in quitting because the damage is already done,” said Simon Chapman, Emeritus Professor in the School of Public Health at the University of Sydney, Australia. “But if smokers quit by middle age, they can avoid nearly all the excess risk of tobacco-caused deaths.” It’s estimated that a 40-year-old smoker could potentially live 9 years longer after having quit smoking as compare to continued smoking.

Additional sources: New Scientist, Los Alamos National Laboratory via EurekAlert!

About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
MAY 20, 2018
Clinical & Molecular DX
MAY 20, 2018
EEG Helps Determine the Right Depression Treatment
Scientists want to find effective treatments for mental health disorders, by looking to physiological markers of health and disease....
MAY 21, 2018
Genetics & Genomics
MAY 21, 2018
Using CRISPR for High-throughout Genetic Assessment
Researchers can now move beyond the painstaking manipulation of individual genes....
JUN 11, 2018
Clinical & Molecular DX
JUN 11, 2018
Nasal Brush Test for Asthma Diagnosis
Diagnosing mild-to-moderate asthma can be difficult to diagnose, especially when scientists need to rule out other respiratory disorders that have similar...
JUN 18, 2018
Immunology
JUN 18, 2018
Detecting and Diagnosing Rheumatoid Arthritis Before it Begins
Unique gene signatures and tiny changes in the immune system that occur in the earliest stages of rheumatoid arthritis, an autoimmune disease, could soon b...
JUL 01, 2018
Videos
JUL 01, 2018
Growing Patient Cells on a Chip for Personalized Drug Screens
This work could help eliminate animal models, and tailor medicine to the patient....
AUG 01, 2018
Cell & Molecular Biology
AUG 01, 2018
Levels of One Molecule, LAC, can Diagnose Depression
Depression can be hard to classify and therefore, challenging to treat. New work could help change that....
Loading Comments...