Puff, puff. But do not hold your breath if you're waiting for a drug to repair the damage.
Even after kicking the habit nicotine, ex-puffers scary side by side of getting lung cancer. But a new study offers hope that there might one day be a way to reverse the damage of smoking pack-a-day.
After the assault carcinogens in tobacco smoke, certain lung cells genetically damaged continue to survive and reproduce. The problems can accumulate with each new generation of cells, eventually causing lung cancer. Efforts to prevent lung cancer have focused on some of the early warning signals of the body. One of these flags is reduced expression of a gene called b retinoic acid (RAR b ), which normally contributes to regulating cell growth, differentiation and death. lungs damaged by smoke have fewer receptors for compounds called retinoids that stimulate RAR b expression.
Reasoning that a dose of retinoids could stimulate additional RAR b expression, oncologists Jonathan Kurie and Waun Ki Hong, University of Texas, Dallas, asked 177 former smokers to try two versions. One group was treated with a retinoid called 13-cis-RA, which has been successfully used to slow or prevent the regrowth of tumors of the head and neck. A second group was treated with 9-cis RA, a compound which can bind to many receivers retinoic.
The lung tissue sampled from the team before treatment and after 3 and 6 months. Those with 9-cis-RA showed a small but significant jump in RAR b term - from 69% to 76% of normal expression. There were a lot of bad news too, though. The RA-13-cis treatment was not significantly better than placebo treatment, and no treatment significantly reduces other signs of cancer such as changes in cell shape, arrangement and function. In addition, two retinoids caused severe muscle pain, fatigue and rashes, among other afflictions, the team reports in the February 5 Journal of the National Cancer Institute . Yet Kurie said he is encouraged by the results and think it will be possible to find drugs that stimulate RAR b production without the side effects.
"This is the first evidence that some damage can be reversed in former smokers," says cancer biologist Gregory Riggins Duke University in Durham, North Carolina. Riggins characterized the results as "quite attractive ", but warned that drugs that erase safely damage caused by years of smoking are still far away.
Related Sites
Jonathan Kurie website
the Waun Ki Hong site
site Gregory Riggins
0 Komentar