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Both ethanol and cigarette smoke are classified as human carcinogens. They can synergize, especially in tissues of the upper aerodigestive tract that are targeted by both agents. The main objective of the present study was to evaluate the individual and combined effects of ethanol and smoke in the respiratory tract, either following transplacental exposure and/or postnatal exposure. We designed two consecutive studies in mouse models by exposing Swiss H mice to oral ethanol and/or inhaled mainstream cigarette smoke for up to 4 months, at various prenatal and postnatal life stages. Clastogenic effects and histopathological alterations were evaluated after 4 and 8 months, respectively. Ethanol was per se devoid of clastogenic effects in mouse peripheral blood erythrocytes. However, especially in mice exposed both transplacentally throughout pregnancy and in the postnatal life, ethanol administration was associated not only with liver damage but also with pro-angiogenetic effects in the lung by stimulating the proliferation of blood vessels. In addition, these mice developed pulmonary emphysema, alveolar epithelial hyperplasias, microadenomas, and benign tumors. On the other hand, ethanol interfered in the lung carcinogenesis process resulting from the concomitant exposure of mice to smoke. In fact, ethanol significantly attenuated some smoke-related preneoplastic and neoplastic lesions in the respiratory tract, such as alveolar epithelial hyperplasia, microadenomas, and even malignant tumors. In addition, ethanol attenuated cigarette smoke clastogenicity. In conclusion, preclinical studies provide evidence that, in spite of its pulmonary toxicity, ethanol may mitigate some noxious effects of cigarette smoke in the respiratory tract. [ABSTRACT FROM AUTHOR]

Highlights: [•] We evaluated transplacental genotoxicity of 40nm- and 100nm-gold nanoparticles. [•] AuNP-100nm significantly enhanced MN PCE in fetal liver and blood. [•] In fetal lung, out of 1281 miRNA analyzed, 28 were significantly altered in their expression. [•] In fetal liver, 5 miRNA were significantly altered in their expression. [•] Altered miRNAs are involved in cell proliferation, apoptosis, transcription, stress response. [ABSTRACT FROM AUTHOR]

Birth is characterized by a sudden transition from the maternal-mediated respiration to the autonomous pulmonary respiration. Notwithstanding the importance of the involved functional and metabolic changes, little is known about possible DNA alterations occurring in the lung during the perinatal period. We comparatively evaluated genomic and transcriptional changes in the lung of fetuses and newborn Swiss albino mice, whose dams had either been untreated or treated with oral N-acetyl-l-cysteine (NAC) throughout the pregnancy period. In the less than 24 h period elapsing between the end of fetal life and the start of post-natal life, nucleotide alterations occurred in mouse lung, as shown by a significant increase of both bulky DNA adducts and 8-hydroxy-2′-deoxyguanosine levels, detected by 32P post-labeling procedures. The frequency of micronuclei in peripheral blood erythrocytes was not significantly increased after birth. Multigene expression analysis of 746 selected genes, by cDNA arrays, showed that 33 of them (4.4%) were upregulated in the lung of newborn mice, as compared with fetuses. The overexpressed genes were mainly involved in protective mechanism as a response to oxidative changes, alterations of glutathione metabolism, cellular stress, and damage to DNA and proteins. The transplacental treatment with NAC totally prevented birth-related genomic alterations in lung DNA. NAC did not change the basal gene expression in mouse fetal lung, but attenuated the upregulation of most genes involved in oxidative stress, stress response, and DNA repair in the lung of newborn mice. In fact, only 13 genes (1.7%) were overexpressed in newborns from NAC-treated dams. It therefore appears that administration of NAC during pregnancy is beneficial not only to counteract the adverse effects of toxic agents, as supported by previous studies, but also to attenuate birth-related DNA alterations. [Copyright &y& Elsevier]

In spite of the overwhelming epidemiological evidence for cigarette smoke (CS) carcinogenicity, less attention has been paid to the effects of CS as a complex mixture. As assessed in a series of experiments in murine models, the whole-body exposure to mainstream CS induced significant increases of micronucleated cells in the respiratory tract, bone marrow and peripheral blood of adult mice as well as in the liver and peripheral blood of foetuses whose mothers had been exposed throughout pregnancy. Urethane was potently clastogenic in the same cells when injected intraperitoneally. The daily administration of extra-virgin olive oil by gavage produced evident and consistent protective effects in all monitored experimental systems. In contrast, sunflower oil exhibited some adverse effects. Curcumin did not produce any significant effect in the bone marrow of both CS-exposed adults and foetuses but it elicited a dose-dependent protective effect traceable in blood erythrocytes. However, the higher curcumin dose further increased the frequency of micronucleated pulmonary alveolar macrophages. The apparent protective effects produced by lycopene and by a carotenoid mix were overwhelmed by those produced by olive oil, and lycopene even exhibited a worsening effect on the frequency of micronucleated erythroblasts in the bone marrow of urethane-treated adult mice. [Display omitted] • Cigarette smoke increased micronuclei in mouse respiratory and haematopoietic cells. • Urethane was potently clastogenic in the same cells when injected intraperitoneally. • Administration of olive oil by gavage consistently produced protective effects. • In contrast, sunflower oil exhibited some adverse effects. • Curcumin and carotenoids yielded negative or equivocal results. [ABSTRACT FROM AUTHOR]

Abstract: We have investigated alterations of microRNA expression profiles in the apparently healthy lung of mice and rats as an early response to exposure to cigarette smoke, either mainstream (MCS) or environmental, and/or to treatment with chemopreventive agents. Further on, we evaluated microRNA alterations at a later stage, when lung tumors were detectable in MCS-exposed mice. Lung samples were available from previous studies, in which strain H mice had been exposed to MCS for 4 months, starting immediately after birth, and then kept in filtered air for an additional 3 months. Some samples were from MCS-exposed mice treated either with N-acetyl-l-cysteine during pregnancy or with phenethyl isothiocyanate after weaning. The analysis of 576 mouse microRNAs showed that MCS strongly dysregulated microRNA expression and that both chemopreventive agents efficiently attenuated this trend, especially in noncancer tissue. MicroRNA expression was affected by histopathology, with specific signatures related to occurrence of pneumonia, adenoma, or bronchoalveolar carcinoma. Within pairs of samples from individual mice, microRNA analysis discriminated adenomatous tissue and especially carcinomatous tissue from the surrounding normal appearing tissue. A series of microRNA alterations characterized the sequential stages of pulmonary carcinogenesis. The involved functions included oncogene activation, inhibition of oncosuppressor genes, recruitment of undifferentiated stem cells, inflammation, inhibition of gap-junctional intercellular communications, angiogenesis, invasiveness, and metastatization. Thus, microRNA expression profiles in lung are dysregulated by MCS along all steps of the carcinogenesis process and depend on the interplay among exposure to noxious agents, treatment with dietary and pharmacological agents, and occurrence of pulmonary diseases. [Copyright &y& Elsevier]

Abstract: Cigarette smoke (CS) is a major risk factor for cardiovascular diseases, cancer, and other chronic degenerative diseases. UV-containing light is the most ubiquitous DNA-damaging agent existing in nature, but its possible role in cardiovascular diseases had never been suspected before, although it is known that mortality for cardiovascular diseases is increased during periods with high temperature and solar irradiation. We evaluated whether exposure of Swiss CD-1 mice to environmental CS (ECS) and UV-C-covered halogen quartz lamps, either individually or in combination, can cause DNA damage in heart and aorta cells. Nucleotide alterations were evaluated by 32P postlabeling methods and by HPLC-electrochemical detection. The whole-body exposure of mice to ECS considerably increased the levels of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) and of bulky DNA adducts in both heart and aorta. Surprisingly, even exposure to a light that simulated solar irradiation induced oxidatively generated damage in both tissues. The genotoxic effects of UV light in internal organs is tentatively amenable to formation of unidentified long-lived mutagenic products in the skin of irradiated mice. Nucleotide alterations were even more pronounced when the mice were exposed to smoke and/or light during the first 5weeks of life rather than during adulthood for an equivalent period of time. Although the pathogenetic meaning is uncertain, DNA damage in heart and aorta may tentatively be related to cardiomyopathies and to the atherogenesis process, respectively. [Copyright &y& Elsevier]

Abstract: Our recent studies have shown that both cigarette smoke and UV-containing light, which are the most widespread and ubiquitous mutagens and carcinogens in the world, cause systemic genotoxic damage in hairless mice. Further studies were designed with the aim of evaluating the induction of genotoxic and carcinogenic effects in Swiss albino mice exposed to smoke and/or light since birth. We observed that a 4-month whole-body exposure of mice to mainstream cigarette smoke, starting at birth, caused an early and potent carcinogenic response in the lung and other organs. Our further experiments showed that exposure of mice to environmental cigarette smoke, during the first 5 weeks of life, resulted in a variety of significant alterations of intermediate biomarkers, including cytogenetic damage in bone marrow and peripheral blood, formation of lipid peroxidation products, increase of bulky DNA adduct levels, induction of oxidative DNA damage, and overexpression of OGG1 gene in lung, stimulation of apoptosis, hyperproliferation and loss of Fhit protein in pulmonary alveolar macrophages and/or bronchial epithelial cells, and early histopathological alterations in the respiratory tract. Moreover, exposure of mice to UV-containing light, mimicking solar irradiation, significantly enhanced oxidative DNA damage and bulky DNA adduct levels in lung, and synergized with smoke in inducing molecular alterations in the respiratory tract. The baseline OGG1 expression in lung was particularly high at birth and decreased in post-weanling mice. Oxidative DNA damage and other investigated end-points exhibited differential patterns in post-weanling mice and adult mice. The findings of these studies provide a mechanistic clue to the general concept that the neonatal period and early stages of life are critical in affecting susceptibility to carcinogens. [Copyright &y& Elsevier]

Abstract: Chromium(VI) is genotoxic when tested in vitro or injected parenterally in such a way to escape detoxification mechanisms. However, its genotoxicity and potential carcinogenicity are lost, depending on dose and administration route, due to efficient reduction in body fluids and nontarget cells. Chromium(VI) is a Group 1 IARC carcinogen, but only in the respiratory tract and in well-defined occupational settings that involved heavy exposures. Recently, concern has been expressed that oral chromium(VI) may be a gastric carcinogen. We demonstrated that administration of very high doses of chromium(VI) with the drinking water does not induce any clastogenic effect in hematopoietic cells of adult mice and their fetuses. Thereafter, we investigated whether administration of chromium(VI) with the drinking water may induce local genotoxic effects in the gastrointestinal tract. Sodium dichromate dihydrate was administered to mice for 9 consecutive months, at doses corresponding to 5 and 20mg chromium(VI)/l, which exceed drinking water standards by 100 and 400 times, respectively. Under these conditions, chromium(VI) failed to enhance the frequency of DNA–protein crosslinks and did not cause oxidative DNA damage, measured in terms of 8-oxo-2′-deoxyguanosine, in the forestomach, glandular stomach and duodenum. When cells from the same organs were isolated and challenged in vitro with chromium(VI), as positive controls, the same genotoxicity biomarkers were evidently affected. Thus, consistently with the knowledge accumulated in 50 years of research on chromium(VI) kinetics and metabolism, oral chromium(VI) appears to be devoid of genotoxicity in the gastrointestinal tract. After 9 months, we did not observe any variation of tumor yield in skin, lung, forestomach, glandular stomach, and duodenum of chromium(VI)-treated mice. These results are discussed in the light of literature data, also including a recent 2-year carcinogenicity study performed by the National Toxicology Program. [Copyright &y& Elsevier]

Abstract: A review of almost 2000 studies showed that the large majority of 39 putative cancer chemopreventive agents induced “spontaneous” apoptosis. Inhibition of the programmed cell death triggered by a variety of stimuli was consistently reported only with ascorbic acid, α-tocopherol, and N-acetylcysteine (NAC). We performed experimental studies in rodents exposed to cigarette smoke, either mainstream (MCS) or environmental (ECS), and UV-A/B-containing light. The nonsteroidal anti-inflammatory drug sulindac did not affect the apoptotic process in the skin of light-exposed mice and in the lungs of ECS-exposed mice. Likewise, 5,6-benzoflavone, indole-3-carbinol, 1,2-dithiole-3-thione and oltipraz failed to modulate apoptosis in the respiratory tract of ECS-exposed rats. Phenethyl isothiocyanate further enhanced the frequency of apoptosis in pulmonary alveolar macrophages and bronchial epithelial cells, and upregulated several genes in the lung of ECS-exposed rats. Both individually and in combination with oltipraz, NAC inhibited apoptosis in the respiratory tract of rats exposed either to MCS or ECS. Moreover, NAC attenuated the ECS-related overexpression of proapoptotic genes and normalized the levels of proapoptotic proteins in rat lung. The transplacental administration of NAC to mice considerably attenuated gene overexpression in the liver of fetuses exposed to ECS throughout pregnancy. Inhibition of apoptosis by chemopreventive agents reflects their ability to counteract certain upstream signals, such as genotoxic damage, redox imbalances, and other forms of cellular stress that trigger apoptosis. On the other hand, enhancement of apoptosis is a double-edged sword, since it represents a protective mechanism in carcinogenesis but may contribute to the pathogenesis of other degenerative diseases. We suggest that stimulation of apoptosis by so many chemopreventive agents, as reported in the literature, may often reflect the occurrence of toxic effects at high doses. [Copyright &y& Elsevier]

The epidemic of lung cancer and the increase of other tumours and chronic degenerative diseases associated with tobacco smoking have represented one of the most dramatic catastrophes of the 20th century. The control of this plague is one of the major challenges of preventive medicine for the next decades. The imperative goal is to refrain from smoking. However, chemoprevention by dietary and/or pharmacological agents provides a complementary strategy, which can be targeted not only to current smokers but also to former smokers and passive smokers. This article summarises the results of studies performed in our laboratories during the last 10 years, and provides new data generated in vitro, in experimental animals and in humans. We compared the ability of 63 putative chemopreventive agents to inhibit the bacterial mutagenicity of mainstream cigarette smoke. Modulation by ethanol and the mechanisms involved were also investigated both in vitro and in vivo. Several studies evaluated the effects of dietary chemopreventive agents towards smoke-related intermediate biomarkers in various cells, tissues and organs of rodents. The investigated end-points included metabolic parameters, adducts to haemoglobin, bulky adducts to nuclear DNA, oxidative DNA damage, adducts to mitochondrial DNA, apoptosis, cytogenetic damage in alveolar macrophages, bone marrow and peripheral blood erytrocytes, proliferation markers, and histopathological alterations. The agents tested in vivo included N-acetyl-l-cysteine, 1,2-dithiole-3-thione, oltipraz, phenethyl isothiocyanate, 5,6-benzoflavone, and sulindac. We started applying multigene expression analysis to chemoprevention research, and postulated that an optimal agent should not excessively alter per se the physiological background of gene expression but should be able to attenuate the alterations produced by cigarette smoke or other carcinogens. We are working to develop an animal model for the induction of lung tumours following exposure to cigarette smoke. The most encouraging results were so far obtained in models using A/J mice and Swiss albino mice. The same smoke-related biomarkers used in animal studies can conveniently be applied to human chemoprevention studies. We participated in trials evaluating the effects of N-acetyl-l-cysteine and oltipraz in smokers from Italy, The Netherlands, and the People’s Republic of China. We are trying to develop a pharmacogenomic approach, e.g. based on genetic metabolic polymorphisms, aimed at predicting not only the risk of developing cancer but also the individual responsiveness to chemopreventive agents. [Copyright &y& Elsevier]

Many drugs in common use possess pleiotropic properties that make them capable of interfering with carcinogenesis mechanisms. We discuss here the ability of pharmacological agents to mitigate the pulmonary carcinogenicity of mainstream cigarette smoke. The evaluated agents include anti-inflammatory drugs (budesonide, celecoxib, aspirin, naproxen, licofelone), antidiabetic drugs (metformin, pioglitazone), antineoplastic agents (lapatinib, bexarotene, vorinostat), and other drugs and supplements (phenethyl isothiocyanate, myo-inositol, N -acetylcysteine, ascorbic acid, berry extracts). These drugs have been evaluated in mouse models mimicking interventions either in current smokers or in ex-smokers, or in prenatal chemoprevention. They display a broad spectrum of activities by attenuating either smoke-induced preneoplastic lesions or benign tumors and/or malignant tumors. Together with epidemiological data, these findings provide useful information to predict the potential effects of pharmacological agents in smokers. [ABSTRACT FROM AUTHOR]

Abstract: Postgenomic methodologies have provided novel tools for evaluating safety and efficacy of cancer chemopreventive agents. We exposed rats to environmental cigarette smoke (ECS) for 28 days, with or without oral administration of N-acetylcysteine (NAC). As assessed by 32P-postlabelling, ECS caused a 10-fold increase of DNA adduct levels, which were significantly reduced by NAC. Of 518 proteins tested by antibody microarray, ECS stimulated 56 activities involved in stress response, protein removal, cell replication, apoptosis, phagocytosis, and immune response. NAC alone did not change the amounts of any protein, whereas it significantly decreased the amounts of 6 ECS-induced proteins. The intensity of expression of 278 related genes, assessed by cDNA microarray, was significantly correlated with protein amounts. These observed molecular alterations, which can be attenuated by NAC, represent in part adaptive responses and in part reflect mechanisms contributing to the pathogenesis of smoke-related diseases, including lung cancer, asthma, chronic bronchitis, and emphysema. [Copyright &y& Elsevier]