MELANOMA AND DYSPLASTIC NEVI DEVELOPMENT AFTER RANITIDINE/RILMENIDINE/МOXONIDINE, LERCANIDIPINE, ROSUVASTATIN AND VERAPAMIL/TRANDOLAPRIL - NEW DATA/CASE SERIES. THE POTENTIAL ROLE OF NITROSAMINE/NDSRIS CONTAMINATION IN POLYMEDICATION AS SUBSTANTIAL SKIN CANCER TRIGGERING FACTOR.

The idea of drug-induced/exogenic Nitrosogenesis is driven by the possibility of prolonged exposure of the human body to the influence of nitrosamines within the drug intake - substances or contaminants that have been proven to be carcinogenic or mutagenic one.Until recently, there was a complete lack of data in the scientific literature on the relationship between cancer, polymedication and polycontamination with nitrosamines. In the last decade, melanoma has been described repeatedly in the medical literature as a possible side-effect within the intake of possibly with nitrosamines contaminated medications such as: Valsartan, Hydrochlorothiazide, Amlodipine, Nebivolol, Bisoprolol and Perindopril. However, the contribution of the currently presented new data (5 new patients) is also due to the establishment of the possible pathogenetic role (with respect to melanoma) of several completely new drugs, previously unknown to the scientific community (potentially/actually contaminated with carcinogens/nitrosamines), such as: Ranitidine, Rosuvastatin, Lercanidipine, Rilmenidine, Trandolapril, Moxonidine and Verapamil.The leading and connecting link in shared new and old drug combinations of heterogeneous drug classes (polymedication) and melanoma development and progression remains again one and the same: the possible availability of nitroso component in the frame of exogenous nitrosogenesis according to the official FDA lists of 2023.The number of drugs shared as contaminated with nitrosamines after whose intake melanomas occur is increasing. Nitrosogenesis remains a new beginning, a new understanding and new interpretation of the carcinogenesis concerning melanoma, but probably also of cancer in general. Its further elucidation looks more than promising and is yet to come. More than worrying at the moment remains the fact that the scientific community has to clarify if: 1) peak concentrations of nitrosamines or NDSRIs within the framework of monomedication or 2) normal concentrations within the polymedication (catalogued in the list of FDA/ 2023 as potentially contaminated with hypothetical carcinogens), could hide relatively short-term risk of the development of real tumors: cutaneous melanomas and/or their precursor lesions. The validation of the concept of Nitrosogenesis and its relationship to Сarcinogenesis, is achieved in practice on the basis of the following facts: that it is the occurrence of the same monomorphic clinical pattern (melanoma/dysplastic nevi), developing after the intake of drugs with different mechanism of action, contaminated with nitrosamines/NDSRIs. The unifying link between the intake of certain drugs and the development of certain tumours remains the presence of nitrosamines. Ingredients that are present in drug preparations, identified as availability and as carcinogenic potency, but not yet reflected in packaging or prescriptions. The question remains: why?

NITROSAMINES IN COMMONLY PRESCRIBED ANTIHYPERTENSIVES AND THE (UN)CONTROLLED DRUG-INDUCED SKIN CANCER: SIMULTANEOUS DEVELOPMENT OF CUTANEOUS MELANOMA AND MULTIPLE BCC AFTER CONCOMITANT ADMINISTRATION OF BISOPROLOL AND FUROSEMIDE.

The era of nitrosogenesis is the era that is conditioned by the permanent and prolonged intake of carcinogens/mutagens, also known as nitrosamines/NDSRIs in the context of polymedication/polycontamination in polymorbid patients. Until recently, the favoured and universally accepted thesis by the scientific community that polymorbidity determines the risk of developing cancer has been shown to be weakly substantiated and superseded by the more modern notion that: it is the polycontamination with carcinogens in the context of concomitant medication/ polymorbidity that determines to a large extent the risk of developing heterogeneous cancers, including skin cancer: keratinocytic and melanocytic. The FDA is the organization that first pulled back the curtain on the backstage back in 2018 on this topic. It was not until 2023 that the FDA again catalogued over 250 drugs that are affected by contamination with carcinogens/mutagens/NDSRIs having varying carcinogenic potencies graded between 1 to 5. The expectations of clinicians and patients globally at the moment remain hopeful that the diplomatic recommendations of regulators will soon be replaced by more restrictive regimes and sanctions. The reason for the need to clarify this issue quickly is due to the following circumstances: 1) The reassuring calls and analyses of the regulators that the minimum intake of carcinogens ( nitrosamines or intake within reference values) , could not become a threat to the health of patients even after 70 years of intake, appear to be rather inconsistent; 2) Lack of any official data on any drug batch that has at least been declared by the FDA/EMA (if declared at all) as potentially contaminated; 3) Another not insignificant reason is that a number of scientific publications are indicative of exactly the opposite: short-term concomitant intake of polycontaminated drugs leads to short-term cancer development while shortening cumulative survival and quality of life for those affected. Only the transparency of the results of checks carried out on the presence of carcinogens in drug batches can guarantee peace of mind, and this in turn can be guaranteed by the regulatory authorities. 4) In parallel, the number of clinical data indicating an association between the intake of potentially nitrosamine-contaminated drugs (mainly for high blood pressure, but not only) and - in particular - keratinocytic and/or melanocytic skin cancer is growing avalanche-like. The dramatic increase in skin cancer in general/ worldwide is in absolute contradiction to the continuous explanations that the most important factor in the generation of skin cancer is ultraviolet light and sunburn: the incidence of skin cancer is increasing despite the widespread intensive use of sunscreen protection creams, the lack of any sun exposure in certain groups of patients, and its occurrence in areas not exposed to solar radiation. It follows only that solar radiation is not the only and perhaps not the most important factor determining the occurrence and progression of skin cancer. We report another concomitant intake of potentially nitrosamine contaminated blood pressure medications: bisoprolol and furosemide, taken over a period of 7 years that resulted in the concurrent occurrence of a medium-thickness cutaneous melanoma and 2 basal cell carcinomas. Successful surgical treatment of the tumors was performed, and the role of concurrent administration of ˝hypothetical˝ class 4 carcinogens within the framework of polymedication, polycontamination, and polymorbidity is discussed.

NITROSOGENESIS OF SKIN (HUMAN) CANCER- THE HIDDEN TRUTH OF A NEVERENDING STORY: NITROSAMINE CONTAMINATION IN OLMESARTAN, VALSARTAN AND HCT AS MAIN RISK FACTOR FOR THE DEVELOPMENT OF KERATINOCYTE CANCER.

The pathogenesis of skin cancer remains shrouded in mystery. Nevertheless, a substantial amount of new data is now available to provide a logical explanation regarding the possible link between 1) the occurrence of single or multiple acquired/somatic mutations and 2) the generation and progression of skin cancer, as well as 3) the potential association of the above two facts with the availability of nitrosamines in drugs for hypertension, diabetes, gastritis, acne, tuberculosis, various other antibiotics, etc. The nitrosogenesis of skin cancer is slowly but surely being established as a significant concept that could not be ignored for longer periods of time. It should only be analysed in detail with a view to future prevention for the benefit of public health. The nitrosogenesis of skin cancer is slowly but surely being established as a significant concept that cannot be ignored for longer periods of time. It should only be analysed in detail with a view to future prevention for the benefit of public health. Although this information has been known for decades (but in relation to the development of other cancers), there is still no comparative analysis of the mutations that occur after ingestion of a particular mutagen, also known as nitrosamine. This analysis could to some extent highlight/support or reject to some extent the thesis of the role of nitrosamines and genetic instability leading to the subsequent generation of a malignant cell clone. The notion of skin cancer nitrosogenesis should become a priority concept very soon, but it should also become an evidential memory, a byword, and an equivalent of the ignorance with which modern civilization has treated its own health for decades within the processes of globalization. It is these processes that include nitrosamines as a major component of the "medicinal and nutritional menu" of patients. It remains unclear at present why regulatory authorities are making endless attempts to legalise the availability of a number of mutagens/human carcinogens in the most commonly distributed medicines worldwide. And to persuade "others" that there is no risk from their permanent, controlled and long-term intake. The newly introduced regulatory norms in practice concern the potential/permissive availability of nitrosamines in a serious number of drugs: drugs with radically different mechanisms of action such as: ranitidine, metformin, ACE inhibitors, beta blockers, thiazide diuretics, sartans, rifampicin, but also probably a number of others. However, the occurrence of identical, similar patterns of cancers (skin cancers) following their administration (after ingestion of different classes of drugs) makes the ubiquitous permissive availability of nitrosamines (in each class of these drugs) the most potent and most likely pathogenetic inducer of cancer. These comparative patterns of skin tumor occurrence should have even stronger evidentiary value than even so-called prospective follow-ups. Nitrosamines are and remain one of the best studied mutagens/carcinogens that can alter/modify the human genome. A fact underlined repeatedly over the years (also based on in vivo data, repeatedly ignored) and a fact that, according to the literature, concerns mainly tire industry workers (British rubber workers). It is in this category of patients and after exposure to high doses of nitrosamines (potential inhalation intake) that high mortality has been found in bladder, lung, stomach, oesophageal cancer, multiple myeloma, leukaemia, prostate cancer, pancreatic cancer, and liver cancer. Similar international observations (in vivo/Sweden) concerning intensive human exposure (Swedish rubber workers) to high doses of nitrosamines in a working atmosphere (inhalation type of carcinogen uptake) emphasize the resulting direct subsequent risk of other alarming symptoms such as: nasal bleeds, eye and throat symptoms, hoarseness, cough, nausea, headache, and altered levels of eosinophils and total immunoglobulin G (IgG), compared with unexposed patients. The neglect of these important observations over the years has led to the ubiquitous and currently difficult to counteract and unpunished prevalence of nitrosamines in even the most commonly distributed drugs worldwide (except in the food industry). It is precisely because of this fact that it should come as no surprise to anyone that there is new evidence of an avalanche in the number of new cancers after ingestion of potentially nitrosamine-contaminated preparations. Skin cancer could be seen in the near future precisely as a model of a side reaction after application or long-term contact with mutagens called nitrosamines. Based on the above, and wishing to add to the worldwide data on the heterogeneous cancers that occur after contact with nitrosamines, we draw the attention of the scientific community to the risk of developing keratinocytic cancer after ingestion of nitrosamine-contaminated drugs: sartans and thiazide diuretics. We believe that the role of the generic substance in these drugs could also contribute to some extent to the progression of an already present tumour branch, but this influence is rather minor and without significant clinical relevance. We present a patient who had been taking 2 sartans (valsartan/ olmesartan) over the years as monotherapy and in combination with hydrochlorothiazide, who developed over time and within this intake two forms of keratinocytic cancer: verrucous carcinoma and basal cell carcinoma. The focus of discussion concerns a newly introduced medical concept: nitrosogenesis of skin cancer. The detailed study of nitrosogenesis should be a major, primary task for regulators, researchers, clinicians, and pharmaceutical companies.

THE NITROSAMINE CONTAMINATION IN BETA BLOCKERS (BISOPROLOL/METOPROLOL), ACE INHIBITORS (LISINOPRIL/PERINDOPRIL), THIAZIDES DIURETICS (HCT), CALCIUM CHANNEL BLOCKERS (AMLODIPINE/FELODIPINE), SARTANS (CANDESARTAN) AND ТHE SUBSEQUENT SKIN CANCER DEVELOPMENT AND PROGRESSION: APOCALYPSE NOW.

The problem of contamination of the most commonly used medicines with nitrosamines is worsening worldwide. According to recent literature data, this "contamination" is the cause not only of skin cancer (keratinocytic/melanoma) but also of gastrointestinal neoplasms, brain tumours, neuroblastoma, rectal carcinoma, acute lymphoblastic leukaemia, and many others. It is these clinical manifestations that are associated with/ or already directly linked to the nitrosamine content of drugs and food products used by patients in previous periods. And it is this permissive availability/contamination that could prove to be the most likely, powerful inducer of acquired mutations underlying the worldwide cancer pandemic. Of further concern is the evidence of contamination of newer classes of medications by nitrosamines- namely: beta blockers, calcium antagonists and selective serotonin reuptake inhibitors (SSRIs). In practice, mankind faces the problem of certainly over 1 billion patients taking nitrosamine-contaminated drugs: 280 million patients with depression (antidepressants), over 1 billion patients with arterial hypertension (antihypertensive drugs), over half a billion patients with type 2 diabetes mellitus (oral antidiabetic drugs/metformin/ sitagliptin), over 4 billion patients with gastritis (ranitidine), over 5 million with tuberculosis (rifampicin), and probably a number of others. The calculations are apocalyptic, since even if only 20-30% of the groups were affected, the number of patients taking these drugs would, by a rough calculation, currently amount to over 1 billion. And there are certainly other classes of drugs yet to be announced. It is for this reason that we should not be surprised that the data on the development of keratinocyte cancer after intake of nitrosamine-contaminated preparations is growing at a breakneck pace. This data indirectly but strongly confirms the importance of a newly introduced concept in the medical science : Nitrosogenesis of skin cancer. A concept, until recently unknown, incomprehensible, but at the same time frightening and gradually accepted, imposing itself and which with each passing day is gaining more and more scientific significance and "visibility", "scientific tangibility, receptivity, and acceptability." This article presents, for the first time in the world literature, patients who developed single/multiple forms of keratinocytic cancer (partly in combination with melanoma precursors-dysplastic moles) after administration of two new classes of potentially nitrosamine-contaminated antihypertensive drugs: beta blockers (bisoprolol, metoprolol) and calcium antagonists (amlodipine, felodipine). For the first time in the scientific literature, the contributory pro-carcinogenic role of another potentially nitrosamine-contaminated ACE inhibitor- lisinopril , as well as that of candesartan: in the development of keratinocytic cancer is also discussed. For the first time in the world literature, the conclusion regarding the pathogenetic relationship between the intake of potentially contaminated drugs (from different drug groups) and cancer development is based on the model of the equivalent clinical manifestation of skin tumors (rather than on controlled long-term prospective analyses). Nitrosamine contamination in these drug groups appears to be the sole and major unifying factor or causative agent for these manifestations.

Combinatory lung tumor inhibition by myo-inositol and iloprost/rapamycin: association with immunomodulation.

Although both preclinical and clinical studies have suggested that myo-inositol (MI) may be a safe and effective lung cancer chemopreventive agent, its efficacy is moderate. To test whether the chemopreventive agents iloprost (IL) or rapamycin enhance the lung tumor inhibitory effects of MI, A/J mice were treated with the tobacco smoke carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and, beginning one week after the end of NNK treatment, given MI, IL, rapamycin, MI + IL or MI + rapamycin for 17 weeks. Analyses of the number and size of tumors on the surface of the lung have indicated that MI, IL, rapamycin, MI + IL and MI + rapamycin reduced the multiplicity of NNK-induced lung tumors by 41, 34, 46, 79 and 67%, respectively, and larger tumors (lung tumors with a diameter of 1-2 or >2 mm) were absent in the MI + IL and MI + rapamycin groups. These results clearly indicated that MI + IL and MI + rapamycin are more effective than MI alone in inhibiting the formation and growth of lung tumors. Assessment of the immunomodulatory effects of the drugs showed that whereas MI + rapamycin and MI + IL increased the infiltration of lung tumors by CD4+ and CD8+ T cells, MI + rapamycin reduced the expression of the immune checkpoint protein programmed-death ligand-1 (PD-L1). Moreover, all treatments, except IL, increased apoptosis, whereas cell proliferation was markedly suppressed in all treated groups. In summary, these results suggest that IL and rapamycin could enhance the efficacy of MI in lung cancer chemoprevention trials.

Non-Acid Fluid Exposure and Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) accounts for the large majority of esophageal cancer cases worldwide. In this review, we examine the potential role of non-acidic fluid (NAF) exposure in ESCC carcinogenesis. Esophageal NAF consists of a mixture of salivary, esophageal, gastric, and duodenal fluids, containing inflammatory constituents such as digestive enzymes and bile acids that induce DNA damage, as well as known carcinogens such as acetaldehyde and N-nitrosamines. Exposure to NAF can occur in the setting of increased non-acid reflux, decreased gastric acidity, and decreased esophageal fluid clearance. Non-acid reflux has been associated with ESCC in small observational studies, and in animal models bile reflux can promote the development of ESCC. Associations have been found between increased ESCC risk and atrophic gastritis, a history of partial gastrectomy, and proton pump inhibitor use, all of which raise the pH of refluxate. Additionally, a minimally or non-acidic gastric environment contains an altered microbiome that can increase the production of acetaldehyde and N-nitrosamines. Esophageal motility disorders such as achalasia and opioid-induced esophageal dysfunction result in increased stasis and exposure to these potentially proinflammatory constituents of NAF. NAF may promote the development of ESCC via multiple mechanisms and is an understudied area of research.

Lifetime cumulative exposure to rubber dust, fumes and N-nitrosamines and non-cancer mortality: a 49-year follow-up of UK rubber factory workers.

OBJECTIVES: To examine associations between occupational exposures to rubber dust, rubber fumes and N-nitrosamines and non-cancer mortality. METHODS: A cohort of 36 441 males aged 35+ years employed in British rubber factories was followed-up to 2015 (94% deceased). Competing risk survival analysis was used to assess risks of dying from non-cancer diseases (respiratory, urinary, cerebrovascular, circulatory and digestive diseases). Occupational exposures to rubber dust, rubber fumes, N-nitrosamines were derived based on a population-specific quantitative job-exposure matrix which in-turn was based on measurements in the EU-EXASRUB database. RESULTS: Exposure-response associations of increased risk with increasing exposure were found for N-nitrosomorpholine with mortality from circulatory diseases (subdistribution hazard ratio (SHR) 1.17; 95% CI 1.12 to 1.23), ischaemic heart disease (IHD) (SHR 1.19; 95% CI 1.13 to 1.26), cerebrovascular disease (SHR 1.19; 95% CI 1.07 to 1.32) and exposures to N-nitrosodimethylamine with respiratory disease mortality (SHR 1.41; 95% CI 1.30 to 1.53). Increased risks for mortality from circulatory disease, IHD and digestive diseases were found with higher levels of exposures to rubber dust, rubber fumes and N-nitrosamines sum, without an exposure-dependent manner. No associations were observed between rubber dust, rubber fumes and N-nitrosamines exposures with mortality from asthma, urinary disease, bronchitis, emphysema, liver disease and some digestive diseases. CONCLUSIONS: In a cohort of rubber factory workers with 49 years of follow-up, increased risk for mortality from circulatory, cerebrovascular, respiratory and digestive diseases were found to be associated with cumulative occupational exposures to specific agents.

Impact of tobacco-specific nitrosamine-derived DNA adducts on the efficiency and fidelity of DNA replication in human cells.

The tobacco-derived nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) are known human carcinogens. Following metabolic activation, NNK and NNN can induce a number of DNA lesions, including several 4-(3-pyridyl)-4-oxobut-1-yl (POB) adducts. However, it remains unclear to what extent these lesions affect the efficiency and accuracy of DNA replication and how their replicative bypass is influenced by translesion synthesis (TLS) DNA polymerases. In this study, we investigated the effects of three stable POB DNA adducts (O2-POB-dT, O4-POB-dT, and O6-POB-dG) on the efficiency and fidelity of DNA replication in HEK293T human cells. We found that, when situated in a double-stranded plasmid, O2-POB-dT and O4-POB-dT moderately blocked DNA replication and induced exclusively T→A (∼14.9%) and T→C (∼35.2%) mutations, respectively. On the other hand, O6-POB-dG slightly impeded DNA replication, and this lesion elicited primarily the G→A transition (∼75%) together with a low frequency of the G→T transversion (∼3%). By conducting replication studies in isogenic cells in which specific TLS DNA polymerases (Pols) were deleted by CRISPR-Cas9 genome editing, we observed that multiple TLS Pols, especially Pol η and Pol ζ, are involved in bypassing these lesions. Our findings reveal the cytotoxic and mutagenic properties of specific POB DNA adducts and unravel the roles of several TLS polymerases in the replicative bypass of these adducts in human cells. Together, these results provide important new knowledge about the biological consequences of POB adducts.

Job-exposure matrix for historical exposures to rubber dust, rubber fumes and n-Nitrosamines in the British rubber industry.

OBJECTIVES: To develop a quantitative historical job-exposure matrix (JEM) for rubber dust, rubber fumes and n-Nitrosamines in the British rubber industry for 1915-2002 to estimate lifetime cumulative exposure (LCE) for a cohort of workers with 49 years follow-up. METHODS: Data from the EU-EXASRUB database-rubber dust (n=4157), rubber fumes (n=3803) and n-Nitrosamines (n=10 115) collected between 1977 and 2002-were modelled using linear mixed-effects models. Sample year, stationary/personal measurement, industry sector and measurement source were included as fixed explanatory variables and factory as random intercept. Model estimates and extrapolations were used to construct a JEM covering all departments in both sectors of the rubber manufacturing industries for the years 1915-2002. JEM-estimates were linked to all cohort members to calculate LCE. Sensitivity analyses related to assumptions about extrapolation of time trends were also conducted. RESULTS: Changes in rubber dust exposures ranged from -6.3 %/year (crude materials/mixing) to -1.0 %/year (curing) and -6.5 %/year (crude materials/mixing) to +0.5 %/year (finishing, assembly and miscellaneous) for rubber fumes. Declines in n-Nitrosamines ranged from -17.9 %/year (curing) to -1.3 %/year (crude materials and mixing). Mean LCEs were 61 mg/m3-years (rubber dust), 15.6 mg/ m3-years (rubber fumes), 2483.2 µg/m3-years (n-Nitrosamines sum score), 18.6 µg/m3-years (N-nitrosodimethylamine) and 15.0 µg/m3-years (N-itrosomorpholine). CONCLUSIONS: All exposures declined over time. Greatest declines in rubber dust and fumes were found in crude materials and mixing and for n-Nitrosamines in curing/vulcanising and preprocessing. This JEM and estimated LCEs will allow for evaluation of exposure-specific excess cancer risks in the British rubber industry.

Lifetime exposure to rubber dusts, fumes and N-nitrosamines and cancer mortality in a cohort of British rubber workers with 49 years follow-up.

OBJECTIVES: To quantitatively evaluate exposure-response associations between occupational exposures to rubber dust, fumes and N-nitrosamines and cancer mortality in the UK rubber industry. METHODS: Competing risk survival analyses were used to examine cancer mortality risk in a cohort of 36 441 males aged 35+ years employed in the British rubber industry in 1967, followed up to 2015 (94% mortality). Exposure measurements are based on a population-specific quantitative job-exposure matrix for rubber dust, rubber fumes and N-nitrosamines from the EU-EXASRUB project. RESULTS: Exposure (lifetime cumulative (LCE))-response associations were found for N-nitrosomorphiline and all cancers (subdistribution HR (SHR) 1.48, 95% CI 1.39 to 1.57) and cancers of the bladder, stomach, multiple myeloma, oesophagus, prostate and pancreas, as well as for N-nitrosodimethylamine and all cancers (SHR 2.08, 95% CI 1.96 to 2.21) and cancers of the bladder, stomach, leukaemia, multiple myeloma, prostate and liver. LCE to the N-nitrosamines sum were associated with increased risks from all cancers (SHR 1.89, 95% CI 1.78 to 2.01) and cancers of the lung, non-Hodgkin's lymphoma and brain. LCE to rubber dust and fumes are associated with increased mortality from all cancers (rubber dust SHR 1.67, 95% CI 1.58 to 1.78; rubber fumes SHR 1.91, 95% CI 1.80 to 2.03) and cancers of the bladder, lung, stomach, leukaemia, multiple myeloma, non-Hodgkin's lymphoma, oesophagus, prostate, pancreas and liver. CONCLUSIONS: Consistent with previous studies, N-nitrosamines exposures are associated with mortality from cancers of the bladder, lung, stomach, leukaemia, multiple myeloma, oesophagus, prostate, pancreas and liver. The long follow-up with nearly complete mortality enabled estimations of lifetime cancer mortality risk from occupational exposures in the rubber industry.

Electronic cigarette: A recent update of its toxic effects on humans.

Electronic cigarettes (e-cigarettes), battery-powered and liquid-vaporizing devices, were invented to replace the conventional cigarette (c-cigarette) smoking for the sake of reducing the adverse effects on multiple organ systems that c-cigarettes have induced. Although some of the identified harmful components in e-cigarettes were alleged to be measured in lower quantity than those in c-cigarettes, researchers unveiled that the toxic effects of e-cigarettes should not be understated. This review is sought for an attempt to throw light on several typical types of e-cigarette components (tobacco-specific nitrosamines, carbonyl compounds, and volatile organic compounds) by revealing their possible impacts on human bodies through different action mechanisms characterized by alteration of specific biomarkers on cellular and molecular levels. In addition, this review is intended to draw the limelight that like c-cigarettes, e-cigarettes could also be accompanied with toxic effects on whole human body, which are especially apparent on respiratory system. From head to foot, from physical aspect to chemical aspect, from genotype to phenotype, potential alterations will take place upon the intake of the liquid aerosol.

Exposure, respiratory symptoms, lung function and inflammation response of road-paving asphalt workers.

BACKGROUND: Controversy exists as to the health effects of exposure to asphalt and crumb rubber modified (CRM) asphalt, which contains recycled rubber tyres. OBJECTIVE: To assess exposures and effects on airway symptoms, lung function and inflammation biomarkers in conventional and CRM asphalt road pavers. METHODS: 116 conventional asphalt workers, 51 CRM asphalt workers and 100 controls were investigated. A repeated-measures analysis included 31 workers paving with both types of asphalt. Exposure to dust, nitrosamines, benzothiazole and polycyclic aromatic hydrocarbon (PAH) was measured in worksites. Self-reported symptoms, spirometry test and blood sampling were conducted prework and postwork. Symptoms were further collected during off-season for asphalt paving. RESULTS: Dust, PAHs and nitrosamine exposure was highly varied, without difference between conventional and CRM asphalt workers. Benzothiazole was higher in CRM asphalt workers (p<0.001). Higher proportions of asphalt workers than controls reported eye symptoms with onset in the current job. Decreased lung function from preworking to postworking was found in CRM asphalt workers and controls. Preworking interleukin-8 was higher in CRM asphalt workers than in the controls, followed by a decrement after 4 days of working. No differences in any studied effects were found between conventional and CRM asphalt paving. CONCLUSION: CRM asphalt workers are exposed to higher benzothiazole. Further studies are needed to identify the source of nitrosamines in conventional asphalt. Mild decrease in lung function in CRM asphalt workers and work-related eye symptoms in both asphalt workers were observed. However, our study did not find strong evidence for severe respiratory symptoms and inflammation response among asphalt workers.

CYP2A6 genetic polymorphisms and biomarkers of tobacco smoke constituents in relation to risk of lung cancer in the Singapore Chinese Health Study.

Cytochrome P450 2A6 (CYP2A6) catalyzes the metabolism of nicotine and the tobacco-specific lung carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Genetic variation in CYP2A6 may affect smoking behavior and contribute to lung cancer risk. A nested case-control study of 197 lung cancer cases and 197 matched controls was conducted within a prospective cohort of 63 257 Chinese men and women in Singapore. Quantified were five genetic variants of CYP2A6 (*1A, *4, *7, *9 and *12) and urinary metabolites of nicotine [total nicotine, total cotinine, total trans-3'-hydroxycotinine (3HC)] and NNK (total NNAL, free NNAL, NNAL-glucuronide, NNAL-N-glucuronide, and NNAL-O-glucuronide). Higher urinary metabolites of nicotine and NNK were significantly associated with a 2- to 3-fold increased risk of lung cancer after adjustment for smoking intensity and duration. Lower CYP2A6-determined nicotine metabolizer status was significantly associated with a lower ratio of total 3HC over total cotinine, lower total nicotine equivalent and reduced risk of developing lung cancer (all Ptrend < 0.001). Compared with normal metabolizers, odds ratios (95% confidence intervals) of developing lung cancer for intermediate, slow and poor metabolizers determined by CYP2A6 genotypes were 0.85 (0.41-1.77), 0.55 (0.28-1.08) and 0.32 (0.15-0.70), respectively, after adjustment for smoking intensity and duration and urinary total nicotine equivalents. Thus the reduced risk of lung cancer in smokers with lower CYP2A6 activity may be explained by lower consumption of cigarettes, less intense smoking and reduced CYP2A6-catalyzed activation of the tobacco-specific lung carcinogen NNK.

Tobacco-specific N-nitrosamines and polycyclic aromatic hydrocarbons in cigarettes smoked by the participants of the Shanghai Cohort Study.

Our recent studies on tobacco smoke carcinogen and toxicant biomarkers and cancer risk among male smokers in the Shanghai Cohort Study showed that exposure to tobacco-specific nitrosamines (TSNA) and polycyclic aromatic hydrocarbons (PAH) is prospectively associated with the risk of cancer. These findings support the hypothesis that the smokers' cancer risk is a function of the dose of select tobacco carcinogens and highlight the importance of understanding the factors that affect the intake of these carcinogens by smokers. Given that tobacco constituent exposures are driven, at least in part, by the levels of these constituents in cigarette smoke, we measured mainstream smoke TSNA and PAH levels in 43 Chinese cigarette brands that participants of the Shanghai Cohort Study reported to smoke. In all brands analyzed here, mainstream smoke levels of NNN and NNK, the two carcinogenic TSNA, were generally relatively low, averaging (±SD) 16.8(±25.1) and 14.2(±9.5) ng/cigarette, respectively. The levels of PAH were comparable to those found in U.S. cigarettes, averaging 15(±9) ng/cigarette for benzo[a]pyrene, 119(±66) ng/cigarette for phenanthrene and 37(±19) ng/cigarette for pyrene. Our findings indicate that the generally low levels of NNN and NNK are most likely responsible for the relatively low levels of the corresponding biomarkers in the urine of the Shanghai Cohort Study participants as compared to those found in the U.S. smokers, supporting the role of the levels of these constituents in cigarette smoke in smokers' exposures. Our findings also suggest that, in addition to smoking, other sources contribute to Chinese smokers' exposure to PAH.

Characterization of potential impurities and degradation products in electronic cigarette formulations and aerosols.

E-cigarettes are gaining popularity in the U.S. as well as in other global markets. Currently, limited published analytical data characterizing e-cigarette formulations (e-liquids) and aerosols exist. While FDA has not published a harmful and potentially harmful constituent (HPHC) list for e-cigarettes, the HPHC list for currently regulated tobacco products may be useful to analytically characterize e-cigarette aerosols. For example, most e-cigarette formulations contain propylene glycol and glycerin, which may produce aldehydes when heated. In addition, nicotine-related chemicals have been previously reported as potential e-cigarette formulation impurities. This study determined e-liquid formulation impurities and potentially harmful chemicals in aerosols of select commercial MarkTen(®) e-cigarettes manufactured by NuMark LLC. The potential hazard of the identified formulation impurities and aerosol chemicals was also estimated. E-cigarettes were machine puffed (4-s duration, 55-mL volume, 30-s intervals) to battery exhaustion to maximize aerosol collection. Aerosols analyzed for carbonyls were collected in 20-puff increments to account for analyte instability. Tobacco specific nitrosamines were measured at levels observed in pharmaceutical grade nicotine. Nicotine-related impurities in the e-cigarette formulations were below the identification and qualification thresholds proposed in ICH Guideline Q3B(R2). Levels of potentially harmful chemicals detected in the aerosols were determined to be below published occupational exposure limits.

Tobacco-specific N-nitrosamines NNN and NNK levels in cigarette brands between 2000 and 2014.

The evolution of the levels of tobacco-specific N-nitrosamines (TSNA), N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in mainstream (MS) cigarette smoke is investigated based on smoke and tobacco chemistry data of cigarette brands sold by Philip Morris International (PMI) between 2000 and 2014. A total of 315 cigarette samples representing a wide range of product and design characteristics manufactured by PMI between 2008 and 2014 were analyzed and compared to a previously published dataset of PMI brands manufactured in 2000. The data indicate that there is a substantial reduction of NNN and NNK levels in tobacco fillers and MS cigarette smoke per mg of tar and per mg of nicotine using Health Canada Intense (HCI) machine-smoking regime. This observed reduction in NNN and NNK levels in MS cigarette smoke is also supported by the downward trend observed on NNN and NNK levels in USA flue-cured Virginia and Burley tobacco lots from 2000 to 2014 crops, reflecting effectiveness of measures taken on curing and agricultural practices designed to minimize TSNA formation in tobacco.

A combination of liver fluke infection and traditional northeastern Thai foods associated with cholangiocarcinoma development.

Opisthorchis viverrini infection is one of the risk factors for cholangiocarcinoma (CCA) in northeast Thailand, a region with one of the highest reported incidence rates of CCA. The traditional practice of eating raw fish, repeated exposure to liver flukes, and consumption of nitrosamine-contaminated food are major risk factors for CCA. So far, there have been no reports about which northeastern traditional dishes may be involved in CCA development. The present study, thus, investigated the effects of traditional foods. It focused specifically on the consumption of fermented foods in combination with O. viverrini infection in hamsters. Syrian hamsters were divided into six groups: (i) normal hamsters, (ii) O. viverrini infection only and (iii)-(vi) O. viverrini infection plus fermented foods (pla som-fish fermented for 1 day), som wua-fermented beef, som phag-fermented vegetables, and pla ra-fish fermented for 6 months. Syrian hamster livers were used for analysis of histopathological changes through hematoxylin and eosin; Sirius Red; and immunohistostaining for cytokeratin-19, proliferating cell nuclear antigen, and CA19-9. Hamster sera were used for liver and kidney function tests. Results of all O. viverrini-infected groups and fermented food groups showed that histopathological changes consisted primarily of aggregations of inflammatory cells surrounding the hepatic bile duct, especially at the hilar region. However, there was a difference in virulence. Interestingly, aggregations of inflammatory cells, new bile duct formation, and fibrosis were observed in subcapsular hepatic tissue, which correlated to positive immunohistochemical staining and increased liver function test. The present study suggests that fermented food consumption can exacerbate cholangitis and cholangiofibrosis, which are risk factors for cholangiocarcinoma-associated opisthorchiasis.

Combinations of indole-3-carbinol and silibinin suppress inflammation-driven mouse lung tumorigenesis by modulating critical cell cycle regulators.

Chronic inflammation is an important risk factor for lung cancer. Therefore, identification of chemopreventive agents that suppress inflammation-driven lung cancer is indispensable. We studied the efficacy of combinations of indole-3-carbinol (I3C) and silibinin (Sil), 20 µmol/g diet each, against mouse lung tumors induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and driven by lipopolysaccharide (LPS), a potent inflammatory agent and constituent of tobacco smoke. Mice treated with NNK + LPS developed 14.7±4.1 lung tumors/mouse, whereas mice treated with NNK + LPS and given combinations of I3C and Sil had 7.1±4.5 lung tumors/mouse, corresponding to a significant reduction of 52%. Moreover, the number of largest tumors (>1.0mm) was significantly reduced from 6.3±2.9 lung tumors/mouse in the control group to 1.0±1.3 and 1.6±1.8 lung tumors/mouse in mice given I3C + Sil and I3C alone, respectively. These results were paralleled by significant reductions in the level of proinflammatory and procarcinogenic proteins (pSTAT3, pIκBα and COX-2) and proteins that regulate cell proliferation (pAkt, cyclin D1, CDKs 2, 4, 6 and pRB). Further studies in premalignant bronchial cells showed that the antiproliferative effects of I3C + Sil were higher than the individual compounds and these effects were mediated by targeting cyclin D1, CDKs 2, 4 and 6 and pRB. I3C + Sil suppressed cyclin D1 by reducing its messenger RNA level and by enhancing its proteasomal degradation. Our results showed the potential lung cancer chemopreventive effects of I3C + Sil in smokers/former smokers with chronic pulmonary inflammatory conditions.

Differential Contributions of Alcohol and Nicotine-Derived Nitrosamine Ketone (NNK) to White Matter Pathology in the Adolescent Rat Brain.

AIM: Epidemiologic studies have demonstrated high rates of smoking among alcoholics, and neuroimaging studies have detected white matter atrophy and degeneration in both smokers and individuals with alcohol-related brain disease (ARBD). These findings suggest that tobacco smoke exposure may be a co-factor in ARBD. The present study examines the differential and additive effects of tobacco-specific nitrosamine (NNK) and ethanol exposures on the structural and functional integrity of white matter in an experimental model. METHODS: Adolescent Long Evans rats were fed liquid diets containing 0 or 26% ethanol for 8 weeks. In weeks 3-8, rats were treated with nicotine-derived nitrosamine ketone (NNK) (2 mg/kg, 3×/week) or saline by i.p. injection. In weeks 7-8, the ethanol group was binge-administered ethanol (2 g/kg; 3×/week). RESULTS: Ethanol, NNK and ethanol + NNK caused striking degenerative abnormalities in white matter myelin and axons, with accompanying reductions in myelin-associated glycoprotein expression. Quantitative RT-PCR targeted array and heatmap analyses demonstrated that ethanol modestly increased, whereas ethanol + NNK sharply increased expression of immature and mature oligodendroglial genes, and that NNK increased immature but inhibited mature oligodendroglial genes. In addition, NNK modulated expression of neuroglial genes in favor of growth cone collapse and synaptic disconnection. Ethanol- and NNK-associated increases in FOXO1, FOXO4 and NKX2-2 transcription factor gene expression could reflect compensatory responses to brain insulin resistance in this model. CONCLUSION: Alcohol and tobacco exposures promote ARBD by impairing myelin synthesis, maturation and integrity via distinct but overlapping mechanisms. Public health measures to reduce ARBD should target both alcohol and tobacco abuses.