Project description:Tobacco is mainly consumed in two different forms (smoking and chewing) that vary in their composition and methods of intake. Despite being the leading cause of oral cancer, the molecular mechanisms resulting in malignancy upon tobacco exposure are yet to be fully elucidated. We therefore sought to compare the molecular alterations in oral keratinocytes exposed to smoke and chewing tobacco. OKF6/TERT1 cells were exposed to cigarette smoke condensate or chewing tobacco for progressively increasing durations (2, 4, 6 and 8 months). We employed a TMT-based quantitative proteomics approach to investigate the adverse effects of chronic cigarette smoke or chewing tobacco exposure in oral keratinocytes. LC/MS3 analysis resulted in the quantification of 5,342 proteins and 2,821 proteins in cigarette smoke and chewing tobacco exposed cells, respectively. Upstream regulator analysis indicates the involvement of distinct regulators in CSC exposed cells compared to STE exposed cells. In addition, exome sequencing revealed discrete genetic alterations in cells exposed to each insult. Current analysis defines a clear distinction in the molecular dysregulation in oral cells in response to different tobacco-based insults. Some of the proteins dysregulated in cigarette smoke or chewing tobacco exposed cells may serve as potential early detection biomarkers which could aid in stratification of patients based on tobacco usage history.
Project description:The practice of using chewing tobacco is common in certain socio-economic sections of southern Asia particularly in the Indian subcontinent. The molecular mechanism of smokeless tobacco which leads to malignancy is unclear. Chewing tobacco demonstrates a carcinogenic effect through chronic and not acute exposures. Using a cell line model, we studied the chronic effects of chewing tobacco on the proteome in normal oral keratinocytes (OKF6/TERT1). We carried out iTRAQ-based quantitative proteomic analysis of the untreated and chewing tobacco treated oral keratinocytes. LC-MS/MS analysis of this cell line pair resulted in the identification of 3,638 proteins of which 408 were found to be differentially expressed.
Project description:Tobacco in its smoke and smokeless form are major risk factors for ESCC (esophageal squamous cell carcinoma). However, molecular alterations associated with smokeless tobacco exposure are poorly understood. In the Indian subcontinent, tobacco is predominantly consumed in chewing form. An understanding of molecular alterations associated with chewing tobacco exposure is vital for identifying molecular markers and potential targets. We developed an in-vitro cellular model by exposing non-transformed esophageal epithelial cells to chewing tobacco over eight month period. Chronic exposure to chewing tobacco led to increase in cell proliferation, invasive ability and anchorage independent growth indicating cell transformation. Molecular alterations associated with chewing tobacco exposure were characterized by carrying out exome sequencing and quantitative proteomic profiling of parental cells and chewing tobacco exposed cells. Quantitative proteomic analysis revealed that established cancer stem cell markers are elevated in tobacco treated cells. Decreased expression of enzymes associated with the glycolytic pathway and increased expression of a large number of mitochondrially localized proteins involved in the electron transport chain as well as enzymes of TCA cycle were also identified. Electron micrographs revealed increase in number and size of mitochondria. Based on these observations, we hypothesise that chronic treatment of esophageal epithelial cells with tobacco leads to a cancer stem cell-like phenotype. These cells also show characteristic OXPHOS phenotype which can be potentially targeted as a therapeutic strategy.
Project description:Smoking is the leading cause of preventable death worldwide. It increases the risk for various diseases including respiratory diseases, vascular diseases and different cancers including lung, oral and bladder cancer. Despite being the leading cause of oral cancer, the molecular mechanisms resulting in malignancy upon cigarette smoke exposure are yet to be fully elucidated. It is crucial to note that disease development is observed upon chronic exposure to cigarette smoke, as opposed to a short-term exposure. Hence, we sought to investigate the effect of chronic smoke exposure on normal oral keratinocytes (OKF6/TERT1). We employed tandem mass tag-based quantitative proteomic and phosphoproteomic approaches to investigate the proteomic and signaling changes in OKF6/TERT1 cells chronically exposed to cigarette smoke compared to untreated cells. LC/MS2 analysis resulted in the quantification of 5,067 proteins among which expression of 360 proteins were found to be dysregulated in at least one replicate. Phosphoproteomic analysis revealed quantification of 3,647 phosphopeptides corresponding to 1,801 proteins. Majority of the dysregulated proteins were seen to be involved in cellular processes such as cell growth, cellular communication and energy metabolism. This study will aid in elucidating the effects of smoking in oral cancer and in the identification of potential candidates molecules which could serve as early detection biomarkers or therapeutic targets.
Project description:Gene expression patterns were assessed in normal human bronchial epithelial (NHBE) cells exposed to cigarette smoke from a reference cigarette (2R4F, University of Kentucky) and a typical American brand of "light" cigarettes ("Lights") in order to develop a better understanding of the genomic impact of tobacco exposure, which can ultimately define biomarkers that discriminate tobacco-related effects and outcomes in a clinical setting. NHBE cells were treated with whole cigarette smoke for 15 minutes and alterations to the transcriptome assessed at 2, 4, 8 and 24 hours post-exposure using high-density oligonucleotide microarrays. Keywords: time course, cigarette smoke exposure
Project description:This study reports a comparative assessment of the biological impact of a heated tobacco aerosol from the tobacco heating system (THS) 2.2 and smoke from a combustible 3R4F cigarette. Human organotypic bronchial epithelial cultures were exposed to an aerosol from THS2.2 (a candidate modified-risk tobacco product) or 3R4F smoke at similar nicotine concentrations. A systems toxicology approach was applied to enable a comprehensive exposure impact assessment. Culture histology, cytotoxicity, secreted pro-inflammatory mediators, ciliary beating, and genome-wide mRNA/miRNA profiles were assessed at various time points post-exposure. Series of experimental repetitions were conducted to increase the robustness of the assessment. At similar nicotine concentrations, THS2.2 aerosol elicited lower cytotoxicity compared with 3R4F smoke. No morphological change was observed following exposure to THS2.2 aerosol, even at nicotine concentration three times that of 3R4F smoke. Lower levels of secreted mediators and fewer miRNA alterations were observed following exposure to THS2.2 aerosol than following 3R4F smoke. Based on the computational analysis of the gene expression changes, 3R4F (0.13 mg nicotine/L) elicited the highest biological impact (100%) in the context of Cell Fate, Cell Proliferation, Cell Stress, and Inflammatory Network Models at 4 h post-exposure. Whereas, the corresponding impact of THS2.2 (0.14 mg nicotine/L) was 7.6%.
Project description:Cigarette smoke (CS) is affecting considerably the oral mucosa. Heating, instead of burning, tobacco reduces consistently the amount of toxic compounds and may exert a lower impact on oral health than combusted cigarettes. The carbon-heated tobacco product 1.2 (CHTP1.2) is a potential modified risk tobacco product (MRTP) based on heat-not-burn technology. Using a systems toxicology assessment framework, we compared the effects of exposure to CHTP1.2 aerosol with those of CS from a reference cigarette (3R4F). Human organotypic cultures derived from buccal and gingival epithelia were exposed acutely (28-min) or repeatedly (28 min/day for 3 days), respectively, to two matching concentrations of CHTP1.2 aerosol or 3R4F CS, and a non-diluted (100%) CHTP1.2 aerosol. The results showed an absence of cytotoxicity, reduction in pathophysiological alterations, toxicological marker proteins, and inflammatory mediators following exposure to CHTP1.2 aerosol compared with 3R4F CS. Changes in mRNA and miRNA expression were linked by an integrative analysis approach, suggesting a regulatory role of miRNAs in several smoke/disease-relevant biological processes induced by 3R4F CS. The identification of mechanisms by which potential MRTPs can reduce the impact of tobacco use on biological systems is of great importance in understanding the molecular basis of the smoking harm reduction paradigm.
Project description:Cigarette smoke (CS) is affecting considerably the oral mucosa. Heating, instead of burning, tobacco reduces consistently the amount of toxic compounds and may exert a lower impact on oral health than combusted cigarettes. The carbon-heated tobacco product 1.2 (CHTP1.2) is a potential modified risk tobacco product (MRTP) based on heat-not-burn technology. Using a systems toxicology assessment framework, we compared the effects of exposure to CHTP1.2 aerosol with those of CS from a reference cigarette (3R4F). Human organotypic cultures derived from buccal and gingival epithelia were exposed acutely (28-min) or repeatedly (28 min/day for 3 days), respectively, to two matching concentrations of CHTP1.2 aerosol or 3R4F CS, and a non-diluted (100%) CHTP1.2 aerosol. The results showed an absence of cytotoxicity, reduction in pathophysiological alterations, toxicological marker proteins, and inflammatory mediators following exposure to CHTP1.2 aerosol compared with 3R4F CS. Changes in mRNA and miRNA expression were linked by an integrative analysis approach, suggesting a regulatory role of miRNAs in several smoke/disease-relevant biological processes induced by 3R4F CS. The identification of mechanisms by which potential MRTPs can reduce the impact of tobacco use on biological systems is of great importance in understanding the molecular basis of the smoking harm reduction paradigm.
Project description:Cigarette smoke (CS) is affecting considerably the oral mucosa. Heating, instead of burning, tobacco reduces consistently the amount of toxic compounds and may exert a lower impact on oral health than combusted cigarettes. The carbon-heated tobacco product 1.2 (CHTP1.2) is a potential modified risk tobacco product (MRTP) based on heat-not-burn technology. Using a systems toxicology assessment framework, we compared the effects of exposure to CHTP1.2 aerosol with those of CS from a reference cigarette (3R4F). Human organotypic cultures derived from buccal and gingival epithelia were exposed acutely (28-min) or repeatedly (28 min/day for 3 days), respectively, to two matching concentrations of CHTP1.2 aerosol or 3R4F CS, and a non-diluted (100%) CHTP1.2 aerosol. The results showed an absence of cytotoxicity, reduction in pathophysiological alterations, toxicological marker proteins, and inflammatory mediators following exposure to CHTP1.2 aerosol compared with 3R4F CS. Changes in mRNA and miRNA expression were linked by an integrative analysis approach, suggesting a regulatory role of miRNAs in several smoke/disease-relevant biological processes induced by 3R4F CS. The identification of mechanisms by which potential MRTPs can reduce the impact of tobacco use on biological systems is of great importance in understanding the molecular basis of the smoking harm reduction paradigm.
Project description:Cigarette smoke (CS) is affecting considerably the oral mucosa. Heating, instead of burning, tobacco reduces consistently the amount of toxic compounds and may exert a lower impact on oral health than combusted cigarettes. The carbon-heated tobacco product 1.2 (CHTP1.2) is a potential modified risk tobacco product (MRTP) based on heat-not-burn technology. Using a systems toxicology assessment framework, we compared the effects of exposure to CHTP1.2 aerosol with those of CS from a reference cigarette (3R4F). Human organotypic cultures derived from buccal and gingival epithelia were exposed acutely (28-min) or repeatedly (28 min/day for 3 days), respectively, to two matching concentrations of CHTP1.2 aerosol or 3R4F CS, and a non-diluted (100%) CHTP1.2 aerosol. The results showed an absence of cytotoxicity, reduction in pathophysiological alterations, toxicological marker proteins, and inflammatory mediators following exposure to CHTP1.2 aerosol compared with 3R4F CS. Changes in mRNA and miRNA expression were linked by an integrative analysis approach, suggesting a regulatory role of miRNAs in several smoke/disease-relevant biological processes induced by 3R4F CS. The identification of mechanisms by which potential MRTPs can reduce the impact of tobacco use on biological systems is of great importance in understanding the molecular basis of the smoking harm reduction paradigm.