Project description:Cigarette smoking is the main risk factor for the development of squamous cell lung carcinoma (SCC). However, the smoking-related molecular changes in SCC have not been studied. We wanted to identify genes in both histologically normal bronchial epithelium and SCC samples that are differentially expressed between current and ex-smokers. In addition, to analyze the levels of the smoking-related genes identified in normal bronchial epithelium with the levels in SCC. Gene expression profiles were generated using Agilent whole human genome microarrays in 28 laser microdissected normal bronchus epithelial samples and in 35 laser microdissected SCC samples of current and ex-smokers. Levels of 246 genes, mainly related to oxidative stress response, were significantly different between normal bronchial epithelium of current and ex-smokers. No significant differences were associated with the smoking status in SCC samples. Analysis of the 246 smoking specific genes in SSC from current and ex-smokers also revealed no differences. As a next step, we compared the levels of the smoking-specific gene signature between normal bronchial epithelium from ex- and current smokers to all 34 SCC samples. Twenty-two percent of the upregulated genes are further upregulated in SCC as compared to current smokers. Expression of the downregulated genes was even further downregulated for 79% of the genes in SCC as compared to bronchus epithelium of current smokers. The downregulated genes included several tumour suppressor genes. This study shows that genes upregulated in normal bronchial epithelium of current smokers are expressed at similar levels in SCC samples, while levels of downregulated genes were significantly further reduced in SCC. This indicates that these downregulated genes play a role in SCC oncogenesis.
Project description:A chemopreventive effect of aspirin (ASA) on lung cancer risk is supported by epidemiologic and preclinical studies. Zileuton, a 5-LOX inhibitor has single agent activity and adds to the activity of NSAIDs in preclinical models of tobacco carcinogenesis We hypothesized that COX inhibitor + 5-LOX inhibitor may be more effective than placebo in modulating nasal epithelium gene signatures of tobacco exposure and lung cancer. We conducted a randomized, double-blinded study of low dose ASA plus zileuton vs. double placebo in current smokers to compare modulating effects on nasal epithelium gene expression and arachidonic acid (AA) metabolism. Sixty-three participants were randomized to combined treatment of ASA (81 mg QD) and zileuton (Zyflo CR) two 600 mg extended release tablets BID or placebo pills for 12 weeks. Combined ASA plus zileuton had minimal effects on nasal gene expression of nasal or bronchial gene expression signatures associated with smoking, lung cancer and chronic obstructive pulmonary disease but did favorably modulate a bronchial gene signature of squamous dysplasia. Combined ASA plus zileuton suppressed urinary leukotriene (LTE4) (change of 89.867±68.35 from baseline to 32.25±23.25, p <0.001), a surrogate of 5-LOX mediated AA metabolism but did not suppress urinary prostaglandin E2 metabolite (PGEM), a surrogate of cyclooxygenase-mediated AA metabolism. In conclusion, combined COX and 5-LOX inhibition by combined low dose ASA with zileuton in smokers favorably modulated a bronchial squamous dysplasia gene expression signature in the nasal epithelium of current smokers but had minimal effects on other carcinogenesis gene signatures. This combination decreased 5-LOX but not COX-2 mediated AA metabolism. Nasal gene expression signature determination is a novel approach to biomarker analysis, giving an approximation of the pulmonary milieu without having to perform invasive tissue sampling.
Project description:A description of the transcriptome of human bronchial epithelium should provide a basis for studying lung diseases including cancer. We demonstrate here that minute epithelial specimens obtained by bronchial brushings afford reliable profiling by serial analysis of gene expression (SAGE) leading to lung gene discovery. We have deduced global gene expression profiles of bronchial epithelium and lung parenchyma, based upon a vast data set of nearly two million sequence tags from 21 SAGE libraries generated from individuals with a history of smoking. Cluster and linear regression analysis demonstrate the repeatability and reproducibility of bronchial SAGE libraries, and suggest that the transcriptome of the bronchial epithelium is distinct from that of lung parenchyma and other tissue types. This distinction is highlighted by the abundant expression of signature genes that reflect tissue-specific and region-specific functions. Through our analysis we have identified novel bronchial-enriched genes and a novel transcript variant for surfactant, pulmonary-associated protein B in lung parenchyma. Conspicuously, gene expression associated with ciliogenesis is evident in bronchial epithelium. Additionally, it is noted that a large number of unmapped tags awaits further investigation. This study represents a comprehensive delineation of the bronchial and parenchyma transcriptomes, identifying more than 20,000 known and hypothetical genes expressed in the human lung, constituting one of the largest human SAGE studies reported to date. Keywords: SuperSeries This reference Series links data in the following related Series: GSE3707 Expression profiling of bronchial epithelium GSE3708 Expression profiling of normal lung parenchyma
Project description:19 bronchial epithelial SAGE libraries were constructed and analyzed in this study. Discussed in the study: IDENTIFICATION OF NOVEL LUNG GENES IN BRONCHIAL EPITHELIUM BY SERIAL ANALYSIS OF GENE EXPRESSION Kim M. Lonergan1, Raj Chari1, Ronald J. deLeeuw1, Ashleen Shadeo1, Bryan Chi1, Ming-Sound Tsao2, Steven Jones3, Marco Marra3, Victor Ling1, Raymond Ng1,4, Calum MacAulay5, Stephen Lam5 and Wan L. Lam1 From the 1Department of Cancer Genetics & Developmental Biology, 5Department of Cancer Imaging, 3Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Research Centre, Vancouver, BC, Canada, 2Ontario Cancer Institute / Princess Margaret Hospital, Toronto, ON, Canada, 4the Department of Computer Science, University of British Columbia, Vancouver, BC, Canada A description of the transcriptome of human bronchial epithelium should provide a basis for studying lung diseases including cancer. We demonstrate here that minute epithelial specimens obtained by bronchial brushings afford reliable profiling by serial analysis of gene expression (SAGE) leading to lung gene discovery. We have deduced global gene expression profiles of bronchial epithelium and lung parenchyma, based upon a vast data set of nearly two million sequence tags from 21 SAGE libraries generated from individuals with a history of smoking. Cluster and linear regression analysis demonstrate the repeatability and reproducibility of bronchial SAGE libraries, and suggest that the transcriptome of the bronchial epithelium is distinct from that of lung parenchyma and other tissue types. This distinction is highlighted by the abundant expression of signature genes that reflect tissue-specific and region-specific functions. Through our analysis we have identified novel bronchial-enriched genes and a novel transcript variant for surfactant, pulmonary-associated protein B in lung parenchyma. Conspicuously, gene expression associated with ciliogenesis is evident in bronchial epithelium. Additionally, it is noted that a large number of unmapped tags awaits further investigation. This study represents a comprehensive delineation of the bronchial and parenchyma transcriptomes, identifying more than 20,000 known and hypothetical genes expressed in the human lung, constituting one of the largest human SAGE studies reported to date. Keywords: bronchial epithelium 19 bronchial epithelial SAGE libraries were constructed and analyzed in this study.
Project description:A chemopreventive effect of aspirin (ASA) on lung cancer risk is supported by epidemiologic and preclinical studies. We conducted a randomized, double-blind, placebo controlled study in current heavy smokers to compare modulating effects of intermittent versus continuous low dose ASA on gene signatures of smoking and lung cancer from nasal brushings. Fifty-four participants were randomized to intermittent ASA (ASA 81 mg daily for one week alternating with placebo daily for one week) or continuous ASA (81 mg daily) for 12 weeks. The primary endpoint was modulation of a smoking gene signature in nasal brushings. Other [JB1] endpoints included modulation of nasal and bronchial gene signatures for smoking, lung cancer and chronic obstructive pulmonary disease (COPD) and changes in cyclooxygenase (COX)- and 5-lipoxygenase (LOX)-mediated arachidonic acid (ARA) metabolism. Low dose ASA intervention caused minimal changes in smoking and lung cancer gene signature scores in nasal epithelium of current heavy smokers. The small sample size of the intervention groups may have limited the ability to detect modulation of the gene signatures. Low dose ASA lowered urinary prostaglandin E metabolite, a marker of COX-mediated ARA metabolic pathway with no change in urinary leukotriene E4, a marker of 5-LOX-mediated pathway. Exploratory genomic analysis showed that ASA intervention induced wide-ranging genomic changes in the nasal epithelium, including modulation of the arachidonic acid pathway and wound healing. A companion study is underway using ASA plus zileuton to test dual suppression of COX- and 5-LOX-mediated pathways on these gene signature scores in current heavy smokers.
Project description:Smoking is a significant risk factor for lung cancer, the leading cause of cancer-related deaths worldwide. While microRNAs are regulators of many airway gene-expression changes induced by smoking, their role in modulating changes associated with lung cancer in these cells remains unknown. Here, we use next-generation sequencing of small RNAs in the airway to identify miR-4423 as a novel primate-specific microRNA associated with lung cancer and expressed primarily in mucociliary epithelium. The endogenous expression of miR-4423 increases as bronchial epithelial cells undergo differentiation into mucociliary epithelium in vitro and its overexpression during this process causes an increase in the number of ciliated cells. Furthermore, expression of miR-4423 is reduced in most lung tumors and in cytologically normal epithelium of the mainstem bronchus of smokers with lung cancer. In addition, ectopic expression of miR-4423 in a subset of lung cancer cell lines reduces their anchorage-independent growth and significantly decreases the size of the tumors formed in a mouse xenograft model. Consistent with these phenotypes, overexpression of miR-4423 induces a differentiated-like pattern of airway epithelium gene expression and reverses the expression of many genes that are altered in lung cancer. Together, our results indicate that miR-4423 is a novel regulator of airway epithelium differentiation and that the abrogation of its function contributes to lung carcinogenesis. Small RNA expression was profiled from pooled bronchial airway epithelial cell brushings (n=3 patients/pool) obtained during bronchoscopy from healthy never (NS) and current smokers (S) and smokers with (C) and without (NC) lung cancer. MicroRNA hsa-miR-4423 was over expressed in H1299, Calu6, SW900 and H2170 lung cancer cell lines.
Project description:Smoking is a significant risk factor for lung cancer, the leading cause of cancer-related deaths worldwide. While microRNAs are regulators of many airway gene-expression changes induced by smoking, their role in modulating changes associated with lung cancer in these cells remains unknown. Here, we use next-generation sequencing of small RNAs in the airway to identify miR-4423 as a novel primate-specific microRNA associated with lung cancer and expressed primarily in mucociliary epithelium. The endogenous expression of miR-4423 increases as bronchial epithelial cells undergo differentiation into mucociliary epithelium in vitro and its overexpression during this process causes an increase in the number of ciliated cells. Furthermore, expression of miR-4423 is reduced in most lung tumors and in cytologically normal epithelium of the mainstem bronchus of smokers with lung cancer. In addition, ectopic expression of miR-4423 in a subset of lung cancer cell lines reduces their anchorage-independent growth and significantly decreases the size of the tumors formed in a mouse xenograft model. Consistent with these phenotypes, overexpression of miR-4423 induces a differentiated-like pattern of airway epithelium gene expression and reverses the expression of many genes that are altered in lung cancer. Together, our results indicate that miR-4423 is a novel regulator of airway epithelium differentiation and that the abrogation of its function contributes to lung carcinogenesis. Small RNA expression was profiled from pooled bronchial airway epithelial cell brushings (n=3 patients/pool) obtained during bronchoscopy from healthy never (NS) and current smokers (S) and smokers with (C) and without (NC) lung cancer. MicroRNA hsa-miR-4423 was over expressed in H1299, Calu6, SW900 and H2170 lung cancer cell lines.
Project description:Prior microarray studies of smokers at high risk for lung cancer have demonstrated that heterogeneity in bronchial airway epithelial cell gene expression response to smoking can serve as an early diagnostic biomarker for lung cancer. This study examines the relationship between gene expression variation and genetic variation in a central molecular pathway (NRF2-mediated antioxidant response) associated with smoking exposure and lung cancer. We assessed global gene expression in histologically normal airway epithelial cells obtained at bronchoscopy from smokers who developed lung cancer (SC, n=20), smokers without lung cancer (SNC, n=24), and never smokers (NS, n=8). Functional enrichment showed that the NRF2-mediated antioxidant response pathway differed significantly among these groups. Keywords: Global mRNA expression profiling 21 total arrays (20 unique patients) run on total RNA obtained from Bronchial Epithelium of Smokers with Lung Cancer 30 total arrays (24 unique patients) run on total RNA obtained from Bronchial Epithelium of Smokers without Lung Cancer 9 total arrays (8 unique patients) run on total RNA obtained from Bronchial Epithelium of Never Smokers
Project description:2 normal lung parenchyma SAGE libraries, generated from 2 pools of 4 individuals each Discussed in the study: IDENTIFICATION OF NOVEL LUNG GENES IN BRONCHIAL EPITHELIUM BY SERIAL ANALYSIS OF GENE EXPRESSION Kim M. Lonergan1, Raj Chari1, Ronald J. deLeeuw1, Ashleen Shadeo1, Bryan Chi1, Ming-Sound Tsao2, Steven Jones3, Marco Marra3, Victor Ling1, Raymond Ng1,4, Calum MacAulay5, Stephen Lam5 and Wan L. Lam1 From the 1Department of Cancer Genetics & Developmental Biology, 5Department of Cancer Imaging, 3Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Research Centre, Vancouver, BC, Canada, 2Ontario Cancer Institute / Princess Margaret Hospital, Toronto, ON, Canada, 4the Department of Computer Science, University of British Columbia, Vancouver, BC, Canada A description of the transcriptome of human bronchial epithelium should provide a basis for studying lung diseases including cancer. We demonstrate here that minute epithelial specimens obtained by bronchial brushings afford reliable profiling by serial analysis of gene expression (SAGE) leading to lung gene discovery. We have deduced global gene expression profiles of bronchial epithelium and lung parenchyma, based upon a vast data set of nearly two million sequence tags from 21 SAGE libraries generated from individuals with a history of smoking. Cluster and linear regression analysis demonstrate the repeatability and reproducibility of bronchial SAGE libraries, and suggest that the transcriptome of the bronchial epithelium is distinct from that of lung parenchyma and other tissue types. This distinction is highlighted by the abundant expression of signature genes that reflect tissue-specific and region-specific functions. Through our analysis we have identified novel bronchial-enriched genes and a novel transcript variant for surfactant, pulmonary-associated protein B in lung parenchyma. Conspicuously, gene expression associated with ciliogenesis is evident in bronchial epithelium. Additionally, it is noted that a large number of unmapped tags awaits further investigation. This study represents a comprehensive delineation of the bronchial and parenchyma transcriptomes, identifying more than 20,000 known and hypothetical genes expressed in the human lung, constituting one of the largest human SAGE studies reported to date. Keywords: lung parenchyma 2 normal lung parenchyma SAGE libraries, generated from 2 pools of 4 individuals each
Project description:A description of the transcriptome of human bronchial epithelium should provide a basis for studying lung diseases including cancer. We demonstrate here that minute epithelial specimens obtained by bronchial brushings afford reliable profiling by serial analysis of gene expression (SAGE) leading to lung gene discovery. We have deduced global gene expression profiles of bronchial epithelium and lung parenchyma, based upon a vast data set of nearly two million sequence tags from 21 SAGE libraries generated from individuals with a history of smoking. Cluster and linear regression analysis demonstrate the repeatability and reproducibility of bronchial SAGE libraries, and suggest that the transcriptome of the bronchial epithelium is distinct from that of lung parenchyma and other tissue types. This distinction is highlighted by the abundant expression of signature genes that reflect tissue-specific and region-specific functions. Through our analysis we have identified novel bronchial-enriched genes and a novel transcript variant for surfactant, pulmonary-associated protein B in lung parenchyma. Conspicuously, gene expression associated with ciliogenesis is evident in bronchial epithelium. Additionally, it is noted that a large number of unmapped tags awaits further investigation. This study represents a comprehensive delineation of the bronchial and parenchyma transcriptomes, identifying more than 20,000 known and hypothetical genes expressed in the human lung, constituting one of the largest human SAGE studies reported to date. This SuperSeries is composed of the SubSeries listed below.