pulmicort and phenethyl-isothiocyanate

Lung cancer is the most important cause of death among neoplastic diseases worldwide, and cigarette smoke (CS) is the major risk factor for cancer. Complementarily to avoidance of exposure to CS, chemoprevention will lower the risk of cancer in passive smokers, ex-smokers, and addicted current smokers who fail to quit smoking. Unfortunately, chemoprevention clinical trials have produced disappointing results to date and, until recently, a suitable animal model evaluating CS carcinogenicity was not available. We previously demonstrated that mainstream CS induces a potent carcinogenic response when exposure of mice starts at birth. In the present study, neonatal mice (strain H) were exposed to CS for 120 consecutive days, starting at birth. The chemopreventive agents budesonide (2.4 mg/kg diet), phenethyl isothiocyanate (PEITC, 1,000 mg/kg diet), and N-acetyl-L-cysteine (NAC, 1,000 mg/kg body weight) were administered orally according to various protocols. The experiment was stopped after 210 days. Exposure to CS resulted in a high incidence and multiplicity of benign lung tumors and in significant increases of malignant lung tumors and other histopathological alterations. All three chemopreventive agents, administered to current smokers after weaning, were quite effective in protecting both male and female mice from CS pulmonary carcinogenicity. When given to ex-smokers after withdrawal of exposure to CS, the protective capacity of budesonide was unchanged, while PEITC lost part of its cancer chemopreventive activity. In conclusion, the proposed experimental model provides convincing evidence that it is possible to prevent CS-induced lung cancer by means of dietary and pharmacological agents.

Topics: Acetylcysteine; Animals; Animals, Newborn; Anticarcinogenic Agents; Budesonide; Disease Models, Animal; Female; Isothiocyanates; Lung Neoplasms; Male; Mice; Tobacco Smoke Pollution

Although microRNAs (miRNA) have extensively been investigated in cancer research, less attention has been paid to their regulation by carcinogens and/or protective factors in early stages of the carcinogenesis process. The present study was designed to evaluate the modulation of mRNA expression as related to exposure of neonatal mice to environmental cigarette smoke (ECS) and to treatment with chemopreventive agents. Exposure to ECS started immediately after birth and for 2 weeks after weaning. Thereafter, groups of mice received daily either budesonide (BUD) or phenethyl isothiocyanate (PEITC) with the diet. The expression of 576 miRNAs was evaluated by miRNA microarray in liver and lung. In sham-exposed mice, the expression of miRNAs tended to be higher in liver than in lung. ECS downregulated the expression of a number of miRNAs in lung, whereas mixed alterations were observed in liver. PEITC and BUD did not substantially affect the physiological situation in lung, whereas both agents caused intense variations in liver, reflecting the occurrence of damage mechanisms, such as inflammation, DNA and protein damage, cellular stress, proliferation and apoptosis. PEITC and BUD protected the lung from ECS-induced alterations of miRNA expression but exhibited some adverse effects in liver.

Topics: Animals; Anticarcinogenic Agents; Budesonide; Female; Gene Expression Regulation; Isothiocyanates; Liver; Lung; Mice; MicroRNAs; Nicotiana; Smoke

Our discovery that the perinatal period involves nucleotide modifications and gene overexpression in mouse lung prompted us to evaluate whether mice may become more susceptible to cigarette smoke when exposure starts immediately after birth. We previously showed that mainstream cigarette smoke is a quite potent carcinogen in neonatal mice. Further on, we showed that exposure of mice to environmental cigarette smoke (ECS), starting at birth, results in alterations of a variety of intermediate biomarkers. However, after 4 months of exposure to ECS followed by 7 months of recovery in filtered air, the lung tumor yield was rather low. In the present study, we evaluated the protective effects of the glucocorticoid budesonide and of the dietary agent phenethyl isothiocyanate in mice exposed to ECS for 9 months followed by 2 months of recovery. After weanling, the mice exposed to ECS since birth underwent a variety of alterations of molecular and cytogenetical end points, and 11 months after birth, they exhibited significant histopathologic changes, such as pulmonary anthracosis, emphysema, hemorrhagic areas, alveolar bronchiolarization, bronchial hyperplasia, and tumors, both benign and malignant. The carcinogenic response was less evident in dams exposed to ECS under identical conditions. Both phenethyl isothiocyanate and budesonide, administered daily with the diet after weanling, attenuated several alterations of ECS-related biomarkers and moderately protected the lungs from histopathologic alterations, including tumors. Thus, although not as efficiently as the bioassay in mainstream cigarette smoke-exposed mice, the model in neonatal mice is suitable to evaluate both ECS carcinogenicity and its modulation by chemopreventive agents.

Topics: Adenoma; Age Factors; Animals; Animals, Newborn; Anticarcinogenic Agents; Apoptosis; Bone Marrow Cells; Budesonide; Carcinoma; DNA Adducts; Drug Screening Assays, Antitumor; Epithelial Cells; Female; Isothiocyanates; Lung; Lung Diseases; Lung Neoplasms; Male; Mice; Precancerous Conditions; Pregnancy; Time Factors; Tobacco Smoke Pollution

Chemoprevention by dietary and pharmacological means provides a strategy for attenuating the health risks resulting from cigarette smoking and in particular from passive exposure to environmental cigarette smoke (ECS). We evaluated the ability of the glucocorticoid budesonide and of the natural agent phenethyl isothiocyanate (PEITC) to affect DNA damage in bronchoalveolar lavage (BAL) cells of CD-1 mice exposed to ECS, starting within 12 h after birth and continuing until the end of the experiment. After weanling, based on a preliminary subchronic toxicity study, groups of mice received daily either budesonide (24 mg/kg diet) or PEITC (1,000 mg/kg diet). After 2 weeks of treatment, all mice were sacrificed and subjected to BAL, mainly recovering pulmonary alveolar macrophages. Evaluation of single-cell DNA strand breaks was made by using the alkaline-halo test, a modification of the comet assay. The analysis of 481 BAL cells yielded the following results (expressed as nuclear spread factor): (a) Sham-exposed mice: mean 0.84 (lower-upper 95% confidence intervals 0.74-0.94); (b) ECS-exposed mice: 2.77 (2.46-3.09); (c) ECS-exposed mice treated with PEITC: 1.15 (1.05-1.26); (d) ECS-exposed mice treated with budesonide: 1.37 (1.25-1.49). Thus, exposure to ECS resulted in a significant increase of DNA damage as compared with sham, and both PEITC and budesonide significantly attenuated this damage. In conclusion, the analysis of sentinel cells collected by BAL, a semi-invasive technique that is commonly used in humans for diagnostic purposes, showed that the investigated chemopreventive agents are able to revert the DNA damage produced by passive exposure to cigarette smoke.

Topics: Animals; Bronchoalveolar Lavage Fluid; Budesonide; DNA Damage; Environmental Exposure; Female; Isothiocyanates; Mice; Microscopy, Fluorescence; Nicotiana; Pregnancy; Smoke