Dietary Pattern, Sputum DNA Methylation, and Lung Health: An Epidemiological Study in People Who Ever Smoked.

Background: We previously identified a panel of sputum DNA methylation that predicts lung aging and risk for lung cancer.

Research Question: Can the sputum methylation panel be used as a readout to derive a dietary pattern beneficial for lung health? Is this dietary pattern associated with various subjective and objective lung health phenotypes? Does this relationship vary among people who currently smoke (current smokers) vs previously smoked (former smokers)?

Study Design And Methods: Using the Lovelace Smoker Cohort (LSC), we employed the LASSO (least absolute shrinkage and selection operator) regularized Poisson regression to define a dietary pattern for sputum. Associations of the dietary pattern with objective and subjective lung health measurements were examined using generalized linear and Cox models in the LSC and the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening trial.

Flavored E-cigarette product aerosols induce transformation of human bronchial epithelial cells.

Objectives: E-cigarettes are the most commonly used nicotine containing products among youth. In vitro studies support the potential for e-cigarettes to cause cellular stress in vivo; however, there have been no studies to address whether exposure to e-liquid aerosols can induce cell transformation, a process strongly associated with pre-malignancy. We examined whether weekly exposure of human bronchial epithelial cell (HBEC) lines to e-cigarette aerosols would induce transformation and concomitant changes in gene expression and promoter hypermethylation.

Wood smoke exposure affects lung aging, quality of life, and all-cause mortality in New Mexican smokers.

Background: The role of wood smoke (WS) exposure in the etiology of chronic obstructive pulmonary disease (COPD), lung cancer (LC), and mortality remains elusive in adults from countries with low ambient levels of combustion-emitted particulate matter. This study aims to delineate the impact of WS exposure on lung health and mortality in adults age 40 and older who ever smoked.

Methods: We assessed health impact of self-reported "ever WS exposure for over a year" in the Lovelace Smokers Cohort using both objective measures (i.

Chromatin remodeling by the histone methyltransferase EZH2 drives lung pre-malignancy and is a target for cancer prevention.

Background: Trimethylation of lysine 27 and dimethylation of lysine 9 of histone-H3 catalyzed by the histone methyltransferases EZH2 and G9a impede gene transcription in cancer. Our human bronchial epithelial (HBEC) pre-malignancy model studied the role of these histone modifications in transformation. Tobacco carcinogen transformed HBEC lines were characterized for cytosine DNA methylation, transcriptome reprogramming, and the effect of inhibiting EZH2 and G9a on the transformed phenotype.

Identification of novel epigenetic abnormalities as sputum biomarkers for lung cancer risk among smokers and COPD patients.

Objectives: Smoking is a common risk factor for chronic obstructive pulmonary disease (COPD) and lung cancer. Although COPD patients have higher risk of lung cancer compared to non-COPD smokers, the molecular links between these diseases are not well-defined. This study aims to identify genes that are downregulated by cigarette smoke and commonly repressed in COPD and lung cancer.

5-Azacytidine inhaled dry powder formulation profoundly improves pharmacokinetics and efficacy for lung cancer therapy through genome reprogramming.

Background: Epigenetic therapy through demethylation of 5-methylcytosine has been largely ineffective in treating lung cancer, most likely due to poor tissue distribution with oral or subcutaneous delivery of drugs such as 5-azacytidine (5AZA). An inhalable, stable dry powder formulation of 5AZA was developed.

Methods: Pharmacokinetics of inhaled dry powder and aqueous formulations of 5AZA were compared to an injected formulation.

DNA-PKc deficiency drives pre-malignant transformation by reducing DNA repair capacity in concert with reprogramming the epigenome in human bronchial epithelial cells.

The expression of DNA-dependent protein kinase catalytic subunit (DNA-PKc) is highly variable in smokers and reduced enzyme activity has been associated with risk for lung cancer. An in vitro model of lung pre-malignancy was used to evaluate the role of double-strand break DNA repair capacity in transformation of hTERT/CDK4 immortalized human bronchial epithelial cells (HBECs) and reprograming of the epigenome. Here we show that knockdown of DNA-PKc to levels simulating haploinsufficiency dramatically reduced DNA repair capacity following challenge with bleomycin and significantly increased transformation efficiency of HBEC lines exposed weekly for 12 weeks to this radiomimetic.

p53-Suppressed Oncogene TET1 Prevents Cellular Aging in Lung Cancer.

The role of transcriptional regulator ten-eleven translocation methylcytosine dioxygenease 1 (TET1) has not been well characterized in lung cancer. Here we show that TET1 is overexpressed in adenocarcinoma and squamous cell carcinomas. TET1 knockdown reduced cell growth and and induced transcriptome reprogramming independent of its demethylating activity to affect key cancer signaling pathways.

Common cancer-driver mutations and their association with abnormally methylated genes in lung adenocarcinoma from never-smokers.

Objectives: Lung adenocarcinoma in never-smokers accounts for 15-20% of all lung cancer. Although targetable mutations are more prevalent in these tumors, the biological and clinical importance of coexisting and/or mutually exclusive abnormalities is just emerging. This study evaluates the relationships between common genetic and epigenetic aberrations in these tumors.

Gene Promoter Hypermethylation Detected in Sputum Predicts FEV Decline and All-Cause Mortality in Smokers.

Rationale: Gene promoter hypermethylation detected in sputum assesses the extent of field cancerization and predicts lung cancer (LC) risk in ever-smokers. A rapid decline of FEV is a major driver for development of airway obstruction.

Objectives: To assess the effects of methylation of 12 genes on FEV decline and of FEV decline on subsequent LC incidence using two independent, longitudinal cohorts (i.

Dietary nutrients associated with preservation of lung function in Hispanic and non-Hispanic white smokers from New Mexico.

Background: COPD is the third leading cause of death in the United States. Cigarette smoking accelerates the age-related forced expiratory volume in 1 s (FEV) decline, an important determinant for the genesis of COPD. Hispanic smokers have lower COPD prevalence and FEV decline than non-Hispanic whites (NHWs).

Dietary Nutrient Intake, Ethnicity, and Epigenetic Silencing of Lung Cancer Genes Detected in Sputum in New Mexican Smokers.

Lung cancer gene methylation detected in sputum assesses field cancerization and predicts lung cancer incidence. Hispanic smokers have higher lung cancer susceptibility compared with non-Hispanic whites (NHW). We aimed to identify novel dietary nutrients affecting lung cancer gene methylation and determine the degree of ethnic disparity in methylation explained by diet.

Gene methylation biomarkers in sputum as a classifier for lung cancer risk.

CT screening for lung cancer reduces mortality, but will cost Medicare ∼2 billion dollars due in part to high false positive rates. Molecular biomarkers could augment current risk stratification used to select smokers for screening. Gene methylation in sputum reflects lung field cancerization that remains in lung cancer patients post-resection.

ANK1 Methylation regulates expression of MicroRNA-486-5p and discriminates lung tumors by histology and smoking status.

The intragenic tumor-suppressor microRNA miR-486-5p is often down-regulated in non-small cell lung cancer (NSCLC) but the mechanism is unclear. This study investigated epigenetic co-regulation of miR-486-5p and its host gene ANK1. MiR-486-5p expression in lung tumors and cell lines was significantly reduced compared to normal lung (p < 0.

Gene Methylation Biomarkers in Sputum and Plasma as Predictors for Lung Cancer Recurrence.

Detection of methylated genes in exfoliated cells from the lungs of smokers provides an assessment of the extent of field cancerization, is a validated biomarker for predicting lung cancer, and provides some discrimination when interrogated in blood. The potential utility of this 8-gene methylation panel for predicting tumor recurrence has not been assessed. The Eastern Cooperative Oncology Group initiated a prevention trial (ECOG-ACRIN5597) that enrolled resected stage I non-small cell lung cancer patients who were randomized 2:1 to receive selenized yeast versus placebo for 4 years.

A prospective and retrospective analysis of smoking behavior changes in ever smokers with high risk for lung cancer from New Mexico and Pennsylvania.

Cigarette smoking is the leading preventable cause of death worldwide. The aim of this study is to conduct a prospective and retrospective analysis of smoking behavior changes in the Lovelace Smokers Cohort (LSC) and the Pittsburgh Lung Screening Study cohort (PLuSS). Area under the curve (AUC) for risk models predicting relapse based on demographic, smoking, and relevant clinical variables was 0.

miR-196b Is Epigenetically Silenced during the Premalignant Stage of Lung Carcinogenesis.

miRNA silencing by promoter hypermethylation may represent a mechanism by which lung cancer develops and progresses, but the miRNAs involved during malignant transformation are unknown. We previously established a model of premalignant lung cancer wherein we treated human bronchial epithelial cells (HBEC) with low doses of tobacco carcinogens. Here, we demonstrate that next-generation sequencing of carcinogen-transformed HBECs treated with the demethylating agent 5-aza-2'deoxycytidine revealed miR-196b and miR-34c-5p to be epigenetic targets.

Radon Exposure, IL-6 Promoter Variants, and Lung Squamous Cell Carcinoma in Former Uranium Miners.

Background: High radon exposure is a risk factor for squamous cell carcinoma, a major lung cancer histology observed in former uranium miners. Radon exposure can cause oxidative stress, leading to pulmonary inflammation. Interleukin-6 (IL-6) is a pro-carcinogenic inflammatory cytokine that plays a pivotal role in lung cancer development.

Epigenetic Repression of CCDC37 and MAP1B Links Chronic Obstructive Pulmonary Disease to Lung Cancer.

Introduction: Lung cancer and chronic obstructive pulmonary disease (COPD) share environmental risk factors. COPD also increases the risk of lung cancer; however, the molecular mechanisms are unclear.

Methods: An epigenome-wide association study of lung tumors and cancer-free lung tissue (CFLT) pairs from non-small-cell lung cancer cases with (n = 18) or without (n = 17) COPD was conducted using the HumanMethylation450 beadchip (HM450K).

Implication of a Chromosome 15q15.2 Locus in Regulating UBR1 and Predisposing Smokers to MGMT Methylation in Lung.

O(6)-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that protects cells from carcinogenic effects of alkylating agents; however, MGMT is silenced by promoter hypermethylation during carcinogenesis. A single-nucleotide polymorphism (SNP) in an enhancer in the MGMT promoter was previously identified to be highly significantly associated with risk for MGMT methylation in lung cancer and sputum from smokers. To further genetic investigations, a genome-wide association and replication study was conducted in two smoker cohorts to identify novel loci for MGMT methylation in sputum that were independent of the MGMT enhancer polymorphism.

15q12 variants, sputum gene promoter hypermethylation, and lung cancer risk: a GWAS in smokers.

Background: Lung cancer is the leading cause of cancer-related mortality worldwide. Detection of promoter hypermethylation of tumor suppressor genes in exfoliated cells from the lung provides an assessment of field cancerization that in turn predicts lung cancer. The identification of genetic determinants for this validated cancer biomarker should provide novel insights into mechanisms underlying epigenetic reprogramming during lung carcinogenesis.

GATA2 is epigenetically repressed in human and mouse lung tumors and is not requisite for survival of KRAS mutant lung cancer.

Introduction: GATA2 was recently described as a critical survival factor and therapeutic target for KRAS mutant non-small-cell lung cancer (NSCLC). However, whether this role is affected by epigenetic repression of GATA2 in lung cancer is unclear.

Methods: GATA2 expression and promoter CpG island methylation were evaluated using human and mouse NSCLC cell lines and tumor-normal pairs.

SGI-110 and entinostat therapy reduces lung tumor burden and reprograms the epigenome.

The DNA methyltransferase (DNMT) inhibitor vidaza (5-Azacytidine) in combination with the histone deacetylase inhibitor entinostat has shown promise in treating lung cancer and this has been replicated in our orthotopic lung cancer model. However, the effectiveness of DNMT inhibitors against solid tumors is likely impacted by their limited stability and rapid inactivation by cytidine deaminase (CDA) in the liver. These studies were initiated to test the efficacy of SGI-110, a dinucleotide containing decitabine that is resistant to deamination by CDA, as a single agent and in combination with entinostat.

Native American ancestry affects the risk for gene methylation in the lungs of Hispanic smokers from New Mexico.

Rationale: Gene promoter methylation detected in sputum predicts lung cancer risk in smokers. Compared with non-Hispanic whites (NHW), Hispanics have a lower age-standardized incidence for lung cancer.

Objectives: This study compared the methylation prevalence in sputum of NHWs with Hispanics using the Lovelace Smokers cohort (n = 1998) and evaluated the effect of Native American ancestry (NAA) and diet on biomarkers for lung cancer risk.