Exploring the Utility of Long Non-Coding RNAs for Assessing the Health Consequences of Vaping.

Electronic cigarette (e-cig) use, otherwise known as "vaping", is widespread among adolescent never-smokers and adult smokers seeking a less-harmful alternative to combustible tobacco products. To date, however, the long-term health consequences of vaping are largely unknown. Many toxicants and carcinogens present in e-cig vapor and tobacco smoke exert their biological effects through epigenetic changes that can cause dysregulation of disease-related genes. Long non-coding RNAs (lncRNAs) have emerged as prime regulators of gene expression in health and disease states. A large body of research has shown that lncRNAs regulate genes involved in the pathogenesis of smoking-associated diseases; however, the utility of lncRNAs for assessing the disease-causing potential of vaping remains to be fully determined. A limited but growing number of studies has shown that lncRNAs mediate dysregulation of disease-related genes in cells and tissues of vapers as well as cells treated in vitro with e-cig aerosol extract. This review article provides an overview of the evolution of e-cig technology, trends in use, and controversies on the safety, efficacy, and health risks or potential benefits of vaping relative to smoking. While highlighting the importance of lncRNAs in cell biology and disease, it summarizes the current and ongoing research on the modulatory effects of lncRNAs on gene regulation and disease pathogenesis in e-cig users and in vitro experimental settings. The gaps in knowledge are identified, priorities for future research are highlighted, and the importance of empirical data for tobacco products regulation and public health is underscored.

Epigenomic Dysregulation in Youth Vapers: Implications for Disease Risk Assessment.

Despite the ongoing epidemic of youth vaping, the long-term health consequences of electronic cigarette use are largely unknown. We report the effects of vaping versus smoking on the oral cell methylome of healthy young vapers and smokers relative to non-users. Whereas vapers and smokers differ in number of differentially methylated regions (DMRs) (831 vs 2,863), they share striking similarities in the distribution and patterns of DNA methylation, chromatin states, transcription factor binding motifs, and pathways. There is substantial overlap in DMR-associated genes between vapers and smokers, with the shared subset of genes enriched for transcriptional regulation, signaling, tobacco use disorders, and cancer-related pathways. Of significance is the identification of a common hypermethylated DMR at the promoter of "Hypermethylated In Cancer 1" (HIC1), a tumor suppressor gene frequently silenced in smoking-related cancers. Our data support a potential link between epigenomic dysregulation in youth vapers and disease risk. These novel findings have significant implications for public health and tobacco product regulation.

A Multi-Year Characterization of Confiscated Vaping Products from Virginia School Youth.

The United States (US) Food and Drug Administration's (FDA) regulatory oversight over electronic cigarettes (e-cigs) includes access restriction for persons <21 years of age and flavor restrictions for "cartridge-based" products. Despite the restrictions, consumption by US youth perseveres. Studies on youth e-cig use are limited by the reliability and accuracy of self-reports. As an alternative to self-reports, the current study examined nicotine, cannabinoid, and unlabeled e-cigs and other vaping products confiscated from Virginia public schools to characterize trends among students. Findings highlight a shift from JUUL and pod-based products to single use disposable e-cigs following the FDA flavor restrictions on cartridge-based e-cigs. Chemical analysis of e-liquids by gas chromatography-mass spectrometry identified a wide variety of flavorants and an increase in the prevalence of synthetic coolants. Most confiscated products were nicotine salt formulations, but the prevalence of cannabinoid-based vaping products increased. The popularity of flavored disposable e-cigs highlights the need for further restrictions to reduce youth consumption. The increasing use of synthetic coolants instead of menthol may suggest that manufacturers are employing tactics to bypass regulations. Continued youth access to e-cigs and the abundance of cannabinoid-based products is problematic from health and safety perspectives. Continued research incorporating confiscated product analysis can be used to understand youth access to vaping products and evolutions in manufacturing practices.

Association of anxiety and depression symptoms with perceived health risk of nicotine vaping products for smoking cessation.

As tobacco smoking prevalence is unacceptably high for the one in five Australians reporting a mental health condition in the past year, multiple cessation supports are needed to reduce tobacco-related disease. Nicotine vaping product (NVP)-facilitated smoking cessation is one option requiring a medical prescription in Australia. Yet, people easily obtain NVPs via non-prescription channels. As mental health impacts quitting intentions and health system engagement, this study examined how presence of anxiety and depression symptoms may be associated with perceived health risk of using NVPs from prescription or non-prescription sources for smoking cessation. We used cross-sectional South Australian (15 years +) 2022 survey data on vaping, smoking, anxiety, and depression. Robust linear regression was used to examine the association of anxiety and depression symptoms and nicotine addiction concern on perceived health risk of using NVPs from prescription or non-prescription sources. For prescription NVPs, vaping was associated with lower perceived health risk (b=-0.732). Higher perceived addiction risk was associated with higher perceived health risk from prescription NVPs (b=0.784). For non-prescription NVPs, vaping (b=-0.661) or smoking (b=-0.310) was associated with lower perceived health risk, and higher perceived addiction risk (b=0.733) was associated with a higher perceived health risk. Although anxiety and depression were not directly associated with NVP health risk perceptions, vaping while having depression symptoms was associated with higher perceived health risk ratings for prescription (b=0.700) but not non-prescription sources. People with depression who vape may see health risk barriers in NVP prescription access for smoking cessation, a smoking cessation support gap.

Electronic Cigarette (E-Cig) Use in the Chronic Pain Population.

BACKGROUND: Since electronic cigarettes (E-Cigs) were introduced to the United States (US) in 2007 its use has increased. Like other tobacco products, E-Cigs too pose health risks. Studies have shown a correlation between pain and tobacco use, with the association being bidirectional. However, there is limited data on the effect of E-Cig use on chronic pain, as well as its association with opioid use. OBJECTIVES: To evaluate the use of tobacco products, including E-Cigs in a chronic pain population. STUDY DESIGN: This study was designed as a cross sectional survey. SETTING: This study was set in an urban academic teaching center. METHODS: After IRB approval, surveys of established chronic pain patients were conducted over 4 months. The survey and results were anonymous, without the collection of any identifiable information. The adult patients who had been treated in the pain practice for over 3 months were included in this study. The survey collected the patients' age, gender, history of tobacco usage, cigarette smoking, E-Cig and opioid use. RESULTS: A total of 312 patients were surveyed. 198 women (63.5%) and 114 men (36.5%). The average age was 58.2; ~59 years for men and ~58 years for women. Eighty-four patients (26.9%) were managing pain using chronic opioids; 46 women and 38 men. Nine women (4.5%) had tried E-Cigs in the past, but none (0%) were active users. Eighteen men (15.8%) had tried E-Cigs in the past with 9 (7.8%) being active users. Among the opioid managed patients, 6 (9.1%) had and were active users of E-Cigs and all 6 were men (20%). LIMITATIONS: The anonymous results collected through the survey may not be accurate as they cannot be validated. In addition to the small sample size, the entire study population is from an urban academic center which may not be generalizable to all chronic pain patients. Finally, the study does not evaluate the impact of tobacco or E-Cig use on pain level or functional status. CONCLUSION: In this study of chronic pain patients, cigarette smoking and E-Cig use was similar to the reported use in the general adult population in the US. The study showed a strong correlation between tobacco use, especially cigarettes and E-Cigs, and opioid use. As the use of E-Cigs becomes more mainstream, the association between E-Cig use, chronic pain, and opioid use should be monitored.

Inflammatory biomarker changes in healthy adults secondary to electronic cigarette use: A scoping review.

CONTEXT: There has been a global increase in the use of electronic cigarettes (EC). However, to our knowledge, no review has summarized or categorized changes in inflammatory biomarkers after EC use in the extant literature. OBJECTIVE: To evaluate changes in general, cardiopulmonary, and oxidative stress-related inflammatory biomarkers in healthy adults who use ECs. METHODS: A scoping review was conducted according to the Arksey and O'Malley framework. PubMed and MEDLINE (Ovid) databases were used for our search. After initial pilot searches and discussions, we performed a final search with medical subject headings and plain language terms related to inflammation, biomarkers, ECs, and adult humans. All full-text articles, gray literature, and primary studies dating from the inception of the searched databases to the present were included. Studies of human participants with known confounding medical histories were excluded. RESULTS: Thirty-seven studies met the inclusion criteria. After short-term (<1 month) use, ECs containing nicotine moderately increased cardiovascular (CV) and oxidative stress markers of inflammation. Of all reported results, 50% of CV biomarkers were increased, and 64% of oxidative stress markers were increased. After long-term (>1 month) use, ECs containing nicotine produced mixed results. Two commonly measured biomarkers in this group, matrix metalloproteinase-9 (MMP-9) and interleukin-6 (IL-6), were elevated in 75% and 60% of measured instances, respectively. CONCLUSION: The results of studies evaluated in our scoping review suggested that short-term use of nicotine-containing ECs may result in increased CV and oxidative stress inflammation, contributing to potential CV or neurologic disease development. The results of studies evaluated in our scoping review also suggested that long-term use of nicotine-containing ECs resulted in no significant changes in general inflammatory biomarker levels. A rigorous systematic review and meta-analysis is necessary to corroborate our findings and to determine the effect of long-term EC use on MMP-9 and IL-6 levels.

Using the Theory of Planned Behavior to Anticipate DIY E-juice Mixing among Young Adult International E-cigarette Users.

Background: Trends in young adult use of electronic nicotine delivery systems (ENDS) and experimentation with do-it-yourself (DIY) e-juice mixing are growing around the world. Theoretical frameworks for examining secondary behaviors (i.e., mixing) embedded within a primary behavior (i.e., vaping) are limited, leading to challenges in scholarly understanding of behavioral performance. This study explored the theoretically driven factors surrounding ENDS users' decision to mix DIY e-juice through a multiple behavior test of the theory of planned behavior (TPB). Methods: An international sample of young adult participants aged 18-19 (n=203) was recruited from Prolific for an online crosssectional survey. Path modeling tested four theoretically driven models to explore behavioral performance of mixing. Findings: The data supported TPB expectations and revealed new paths for secondary behavior. Primary perceptions of attitudes, norms, and intention were predictive of the same secondary perceptions. In addition, for both primary and secondary behaviors, perceived norms were a function of perceived attitudes. For the secondary behavior, normative influence was experienced indirectly through perceived attitudes. Conclusion: DIY e-juice mixing is a product of perceived attitudes and behavioral control surrounding mixing as well as perceived attitudes, norms, and intention surrounding general ENDS use. While unregulated DIY experimentation increases among youth, these findings provide a lens for public health efforts seeking to reach and reduce use. Understanding DIY e-juice behaviors is essential to anticipate stockpiling behaviors and negative outcomes from amateur experimentation.

An examination of the social perceptions and vaping preferences of young electronic nicotine delivery system users.

Background: Little research has been conducted on social aspects and preferences of electronic nicotine delivery system (ENDS) use among young ENDS users, and none have examined differences in these aspects and preferences by gender and tobacco use status. Methods: A total of 558 young regular vapers (ages 16-24; vaped at least once a week for the last 3 months) from Nova Scotia were recruited to complete a demographic and vaping questionnaire. A 2 x 3 study design was used to compare participants on social aspects and vaping preferences based on gender (male or female) and tobacco use status (never, former, or current smoker). Chi-square tests were used to determine significant differences, and Bonferroni tests were used to assess over- and under-representation within significant variables. Results: Current tobacco-using male vapers had a higher frequency of experiencing pressure to vape from friends and current employment as compared to females. Former and never tobacco-using male vapers had a higher frequency of parental awareness of their vaping behavior than females. Former tobacco-using female vapers had a higher frequency of being influenced to vape by others they know on social media than males. Both never and former tobacco-using females reported a higher frequency of exposure to vaping content on social media than males. Never tobacco-using female vapers preferred vape pen devices relative to males. Conclusions: Important gender differences by tobacco use status exist and demonstrate differential patterns of social influence for ENDS use and their experiences within this demographic.

Comparative study of the effects of cigarette smoke versus next-generation tobacco and nicotine product extracts on inflammatory biomarkers of human monocytes.

Monocytes exhibiting a pro-inflammatory phenotype play a key role in adhesion and development of atherosclerotic plaques. As an alternative to smoking, next-generation tobacco and nicotine products (NGP) are now widely used. However, little is known about their pro-inflammatory effects on monocytes. We investigated cell viability, anti-oxidant and pro-inflammatory gene and protein expression in THP-1 monocytes after exposure to aqueous smoke extracts (AqE) of a heated tobacco product (HTP), an electronic cigarette (e-cig), a conventional cigarette (3R4F) and pure nicotine (nic). Treatment with 3R4F reduced cell viability in a dose-dependent manner, whereas exposure to alternative smoking products showed no difference to control. At the highest non-lethal dose of 3R4F (20%), the following notable mRNA expression changes were observed for 3R4F, HTP, and e-cig respectively, relative to control; HMOX1 (6-fold, < 2-fold, < 2-fold), NQO1 (3.5-fold, < 2-fold, < 2-fold), CCL2 (4-fold, 3.5-fold, 2.5-fold), IL1B (4-fold, 3-fold, < 2-fold), IL8 (5-fold, 2-fold, 2-fold), TNF (2-fold, 2-fold, < 2-fold) and ICAM1 was below the 2-fold threshold for all products. With respect to protein expression, IL1B (3-fold, < 2-fold, < 2-fold) and IL8 (3.5-fold, 2-fold, 2-fold) were elevated over the 2-fold threshold, whereas CCL2, TNF, and ICAM1 were below 2-fold expression for all products. At higher doses, greater inductions were observed with all extracts; however, NGP responses were typically lower than 3R4F. In conclusion, anti-oxidative and pro-inflammatory processes were activated by all products. NGPs overall showed lower responses relative to controls than THP-1 cells exposed to 3R4F AqE.

Aerosolized nicotine from e-cigarettes alters gene expression, increases lung protein permeability, and impairs viral clearance in murine influenza infection.

E-cigarette use has rapidly increased as an alternative means of nicotine delivery by heated aerosolization. Recent studies demonstrate nicotine-containing e-cigarette aerosols can have immunosuppressive and pro-inflammatory effects, but it remains unclear how e-cigarettes and the constituents of e-liquids may impact acute lung injury and the development of acute respiratory distress syndrome caused by viral pneumonia. Therefore, in these studies, mice were exposed one hour per day over nine consecutive days to aerosol generated by the clinically-relevant tank-style Aspire Nautilus aerosolizing e-liquid containing a mixture of vegetable glycerin and propylene glycol (VG/PG) with or without nicotine. Exposure to the nicotine-containing aerosol resulted in clinically-relevant levels of plasma cotinine, a nicotine-derived metabolite, and an increase in the pro-inflammatory cytokines IL-17A, CXCL1, and MCP-1 in the distal airspaces. Following the e-cigarette exposure, mice were intranasally inoculated with influenza A virus (H1N1 PR8 strain). Exposure to aerosols generated from VG/PG with and without nicotine caused greater influenza-induced production in the distal airspaces of the pro-inflammatory cytokines IFN-γ, TNFα, IL-1ß, IL-6, IL-17A, and MCP-1 at 7 days post inoculation (dpi). Compared to the aerosolized carrier VG/PG, in mice exposed to aerosolized nicotine there was a significantly lower amount of Mucin 5 subtype AC (MUC5AC) in the distal airspaces and significantly higher lung permeability to protein and viral load in lungs at 7 dpi with influenza. Additionally, nicotine caused relative downregulation of genes associated with ciliary function and fluid clearance and an increased expression of pro-inflammatory pathways at 7 dpi. These results show that (1) the e-liquid carrier VG/PG increases the pro-inflammatory immune responses to viral pneumonia and that (2) nicotine in an e-cigarette aerosol alters the transcriptomic response to pathogens, blunts host defense mechanisms, increases lung barrier permeability, and reduces viral clearance during influenza infection. In conclusion, acute exposure to aerosolized nicotine can impair clearance of viral infection and exacerbate lung injury, findings that have implications for the regulation of e-cigarette products.

E-cigarettes may serve as a gateway to conventional cigarettes and other addictive drugs.

Electronic cigarettes (e-cigarettes) are devices that allow the user to inhale nicotine in a vapor, and are primarily marketed as a means of quitting smoking and a less harmful replacement for traditional cigarette smoking. However, further research is needed to determine if vaping nicotine via e-cigarettes can be effective. Conversely, nicotine has been considered a gateway drug to alcohol and other addictive drugs and e-cigarettes containing nicotine may have the same effects. Previous reports have shown that e-cigarette use may open the gate for the use of other drugs including conventional cigarettes, cannabis, opioids, etc. The increasing prevalence of e-cigarettes, particularly among youth and adolescents in the last decade have led to an increase in the dual use of e-cigarettes with alcohol, cannabis, and other illicit drug use like heroin and 3-4-methylenedioxymethamphetamine (MDMA). The advent of e-cigarettes as a device to self-administer addictive agents such as cocaine and synthetic cathinones may bring about additional adverse health effects associated with their concurrent use. This review aims to briefly describe e-cigarettes and their different generations, and their co-use with other addictive drugs as well as the use of the device as a tool to self-administer addictive drugs, such as cocaine, etc.

Effects of E-Cigarette Liquid Ratios on the Gravimetric Filter Correction Factors and Real-Time Measurements.

Electronic cigarettes (ECIGs) generate high concentrations of particulate matter (PM), impacting the air quality inhaled by humans through secondhand exposure. ECIG liquids are available commercially and some users create their own "do-it-yourself" liquids, and these liquids often vary in the amounts of their chemical ingredients, including propylene glycol (PG) and vegetable glycerin (VG). Previous studies have quantified PM concentrations in ECIG aerosol generated from liquids containing different PG/VG ratios. However, the effects of these ratios on aerosol instrument filter correction factors needed to measure PM concentrations accurately have not been assessed. Thus, ECIG aerosol filter correction factors for multiple aerosol instruments (SMPS + APS, MiniWRAS, pDR, and SidePak) were determined for five different PG/VG ratios 1) 0PG/100VG, 2) 15PG/85VG, 3) 50PG/50VG, 4) 72PG/28VG, and 5) 90PG/10VG and two different PM sizes, PM1 (1 µm and smaller) and PM2.5 (2.5 µm and smaller). ECIG aerosols were generated inside a controlled exposure chamber using a diaphragm pump and a refillable ECIG device for all the ratios. In addition, the aerosol size distribution and mass median diameter were measured for all five ECIG ratios. PM2.5 correction factors (5-7.6) for ratios 1, 2, 3, and 4 were similar for the SMPS + APS combined data, and ratios 1, 2, 3 were similar for the MiniWRAS (~2), pDR (~0.5), and SidePak (~0.24). These data suggest different correction factors may need to be developed for aerosol generated from ECIGs with high PG content. The higher correction factor values for the 90PG/10VG ratio may have resulted from greater PG volatility relative to VG and sensor losses. The correction factors (ratios 1-4) for PM2.5 were SMPS + APS data (4.96-7.62), MiniWRAS (2.02-3.64), pDR (0.50-1.07), and SidePak (0.22-0.40). These data can help improve ECIG aerosol measurement accuracy for different ECIG mixture ratios.

Effects of electronic cigarette flavorants on human platelet aggregation ex vivo.

Because little is known about the effects of individual flavorants in electronic cigarette (e-cig) fluids on human platelet aggregation, we tested for the direct effects of 15 common e-cig flavorants on adenosine diphosphate (ADP)-induced human platelet aggregation ex vivo. To better understand a potential mechanism of action of flavorants, we quantified 2 phases of aggregation. Human platelet-rich plasma (PRP) was obtained from whole blood of healthy volunteers and used in a platelet aggregometry assay. PRP was incubated with 1 of 15 different flavorant compounds (e.g., benzyl alcohol, eugenol, citronellol, menthol, menthone, diacetyl, maltol, limonene, methylbutyric acid, isoamyl acetate, acetylpyridine, eucalyptol, 2,5-dimethylpyrazine, cinnamaldehyde, and vanillin) at 100 µM for 5 min at 37 °C prior to addition of ADP (10 µM). Subsequent ADP-induced platelet aggregation was tracked for 5 min using an aggregometer. Aggregation curves were analyzed for flavorant-induced effects on total (%) aggregation, Phase 1 and Phase 2 components, and compared with their ADP-only control via One-Way ANOVA. Notably, eugenol significantly inhibited total aggregation; an effect due solely to inhibition of Phase 2. No other flavor tested had any effect on total or phase-specific ADP-induced platelet aggregation. These results indicate that parent flavorant compounds commonly found in e-cig liquids neither activate nor inhibit ADP-induced human platelet aggregation. However, as flavorants are chemically altered during heating of e-cig, thermally-derived products of flavorants (e.g., flavor acetals) also will need to be tested for effects on platelet activation.

Chronic health effects associated with electronic cigarette use: A systematic review.

Introduction: Over the last decade, e-cigarette use has been on the rise but with growing health concerns. The objective of this systematic review was to update findings for chronic health outcomes associated with e-cigarette use from the 2018 National Academies of Sciences, Engineering, and Medicine (NASEM) report. Methods: Three bibliographic databases were searched to identify studies comparing the chronic health effects of e-cigarette users (ECU) to non-smokers (NS), smokers, and/or dual users indexed between 31 August 2017 and 29 January 2021. Two independent reviewers screened abstracts and full texts. Data were extracted by one reviewer and verified by a second one. Outcomes were synthesized in a narrative manner using counts and based on statistical significance and direction of the association stratified by study design and exposure type. Risk of bias and certainty of evidence was assessed. The protocol was prospectively registered on Open Science Framework https://osf.io/u9btp. Results: A total of 180 articles were eligible. This review focused on 93 studies for the 11 most frequently reported outcomes and from which 59 reported on daily e-cigarette use. The certainty of evidence for all outcomes was very low because of study design (84% cross-sectional) and exposure type (27% reported on exclusive ECU, i.e., never smoked traditional cigarettes). Overall, the summary of results for nearly all outcomes, including inflammation, immune response, periodontal and peri-implant clinical parameters, lung function, respiratory symptoms, and cardiovascular disease, suggested either non-significant or mixed results when daily ECU was compared to NS. This was also observed when comparing exclusive ECU to NS. The only notable exception was related to oral health where most (11/14) studies reported significantly higher inflammation among daily ECU vs. NS. Compared to the smokers, the exclusive-ECUs had no statistically significant differences in inflammation orperiodontal clinical parameters but had mixed findings for peri-implant clinical parameters. Conclusions: This review provides an update to the 2018 NASEM report on chronic health effects of e-cigarette use. While the number of studies has grown, the certainty of evidence remains very low largely because of cross-sectional designs and lack of reporting on exclusive e-cigarette exposure. There remains a need for higher quality intervention and prospective studies to assess causality, with a focus on exclusive e-cigarette use.

Electronic Cigarettes and Vaping in Allergic and Asthmatic Disease.

Electronic nicotine delivery systems (ENDS) were introduced in 2006, offering alternatives to combustible cigarettes. There is significant controversy regarding their sale and regulation, particularly with youth and high-risk patient populations. They were deemed a "major public health concern" by the United States (US) Surgeon General in 2016 . Already associated with health consequences, recently e-cig or vaping product use-associated lung injury (EVALI) has exposed their potential to cause life-threatening complications. This publication aims to educate readers on the the immediate and long-term health consequences of ENDS, so they may provide patient counseling on utilization focusing on the asthmatic population.

Ex vivo toxicity of E-cigarette constituents on human placental tissues.

Globally, ∼50 % of women smoke during pregnancy and the prevalence of vaping is increasing among women of reproductive age. However, the health effects of vaping during pregnancy are largely unknown. This study examined the effects of e-cig constituents alone and in combination (propylene glycol [PG], vegetable glycerin [VG], and nicotine) on human placental tissue viability (MTT assay) and immunoassayed levels of placenta-derived biomarkers, i.e., 8-isoprostane (8-IsoP), heme oxygenase-1 (HO-1), interleukin-6 (IL-6), ß-estradiol (E2), progesterone (P4), allopregnanolone (AP), and brain-derived neurotrophic factor (BDNF). Placental explant cultures were exposed ex vivo for 24 h to media-containing either nicotine (0-5000 nM), PG/VG (0-8 % v/v at 50/50 ratio), or a combination of both. No effects on tissue viability were observed at PG/VG concentrations < 8 % (v/v), while viability significantly reduced at PG/VG concentrations ≥ 10 % (v/v); biomarker studies employed only non-cytotoxic doses. Exposure to PG/VG decreased levels of 8-IsoP, IL-6, and E2, and treatment with 2 % or 8 % PG/VG significantly reduced HO-1 levels, compared to non-treated controls. Exposure to nicotine alone at 2,500 nM and 5,000 nM reduced MTT activity by 20 % (P = 0.04) and 70 % (P < 0.001), respectively, and significantly increased (P < 0.001) levels of HO-1 and BDNF, compared to controls. Treatment with nicotine alone and in combination with PG/VG reduced IL-6 and E2 levels. Interestingly, nicotine-induced toxicity was attenuated by PG/VG addition to nicotine-treated groups. These studies demonstrate that e-cig constituents negatively impact the human placenta and alters production of critical placental biomarkers, suggesting that vaping is an unsafe alternative for pregnant women or their unborn fetus.

Inflammation and Invasion in Oral Squamous Cell Carcinoma Cells Exposed to Electronic Cigarette Vapor Extract.

Electronic cigarettes (eCig) represent a new avenue of tobacco exposure that involves heating oil-based liquids and the delivery of aerosolized flavors with or without nicotine, yet little is known about their overall health impact. The oral cavity is an anatomic gateway for exposure that can be compromised by activating myriad of signaling networks. Oral squamous cell carcinoma (OSSC) is a common malignancy affecting 30,000 people in the United States each year. Our objective was to determine the impact of eCig and nicotine on gingival OSSC invasion and their secretion of pro-inflammatory molecules. Gingiva-derived Ca9-22 cells and tongue-derived Cal27 cells were exposed to eCig vapor extract (EVE) generated from Red Hot or Green Apple (Apple) flavored eCig solution +/- nicotine for 6 hours. Isolation of protein lysates and collection conditioned media was done after treatment. Real-time cellular invasion was assessed using a RTCA DP instrument. Protein expression was determined using western blot. Compared to controls, we observed: elevated NF-kB, TNF-α, ERK, JNK, MMP-13 and cell invasion by Ca9-22 treated with Apple EVE; increased TNF-α and JNK by Ca9-22 treated with Red Hot EVE; and increased TNF-α and JNK by Cal27 cells treated with both Apple and Red Hot EVE. We conclude that eCig flavoring and nicotine orchestrated differential cell invasion and inflammatory effects. This study provides an important initial step in dissecting mechanisms of cancerous invasion and molecular avenues employed by OSCC.