Reactive oxygen species-regulating proteins peroxiredoxin 2 and thioredoxin, and glyceraldehyde-3-phosphate dehydrogenase are differentially abundant in induced sputum from smokers with lung cancer or asbestos exposure.

Lung cancer is a deadly disease, typically caused by known risk factors, such as tobacco smoke and asbestos exposure. By triggering cellular oxidative stress and altering the antioxidant pathways eliminating reactive oxygen species (ROS), tobacco smoke and asbestos predispose to cancer. Despite easily recognizable high-risk individuals, lung cancer screening and its early detection are hampered by poor diagnostic tools including the absence of proper biomarkers. This study aimed to recognize potential lung cancer biomarkers using induced sputum noninvasively collected from the lungs of individuals in risk of contracting lung cancer. Study groups composed of current and former smokers, who either were significantly asbestos exposed, had lung cancer, or were unexposed and asymptomatic. Screening of potential biomarkers was performed with 52, and five differentially abundant proteins, peroxiredoxin 2 (PRDX2), thioredoxin (TXN), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), extracellular matrix protein 1 (ECM1), and protein S100 A8 (S100A8), were chosen to undergo validation, for their previously known connection with oxidative stress or cancer. Results from the validation in 123 sputa showed that PRDX2, TXN, and GAPDH were differentially abundant in sputa from individuals with lung cancer. TXN had a negative correlation with asbestos exposure, yet a positive correlation with smoking and lung cancer. Thus, tobacco smoking, asbestos exposure, and lung carcinogenesis may disturb the cellular redox state in different ways. A strong correlation was found among PRDX2, TXN, GAPDH, and S100A8, suggesting that these proteins may present a diagnostic biomarker panel to aid recognizing individuals at high risk of contracting lung cancer.

Dual use of cigarettes and Swedish snuff (snus) among young adults in Northern Finland.

BACKGROUND: The sale of smokeless tobacco has been totally banned in Finland since the country joined the European Union in 1995. Adolescents have continued to use smokeless tobacco even after the sales ban. The objective was to describe dual use of Swedish snuff (snus) and cigarettes in young adults living in Northern Finland. METHODS: This study on male military recruits (n = 1151, mean age 19.4 years; response rate 80%) investigated association of snus use with self-reported tobacco use, nicotine dependence and attempts to quit smoking. RESULTS: Overall, 15.6% (n = 179) reported daily snus use, and almost half of them were dual users who used both products, i.e. cigarettes and snus, daily. Daily smokers were often occasional snus users (66.3%), and those with dual use smoked equal number of cigarettes per day as daily smokers who were not snus users. In addition, dual snus use seemed to increase the dependence to cigarettes, although this trend did not reach statistical significance. Dual users tried to quit less likely than exclusive smokers. Very few snus users were 'switchers' (ex-smokers) [3.2% (n = 22) of all snus users]. CONCLUSIONS: Dual use of snus and cigarettes is common among young in Finland, despite the sales ban on snus. The role of snus in reducing cigarette smoking is unclear, but it is likely that snus use complicates the attempts to quit smoking.