Approved Abstracts

Title: Measuring Anatalline and Nicotelline to Differentiate Non-combusted Tobacco Use Using the PATH Study

PI: Kathryn Edwards PhD, Westat

Abstract: Although tobacco use remains the leading preventable cause of disease and death in the United States, all tobacco products do not confer similar public health risk. Specifically, combusted products tend to be viewed as more harmful than non-combusted products. One research priority for the Food and Drug Administration (FDA) is to better understand product toxicity including the development and validation of new biomarkers related to non-cigarette tobacco exposure, harm, or toxicity. Biomarkers that are able to distinguish between types of product use are vital to track the impact of regulatory action and associated proximal and distal health effects related to product use. The goal of this study is to measure nicotelline, a minor tobacco alkaloid associated with tobacco smoke particulate matter, in urine biospecimens from Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study. Aims include to validate nicotelline and its utility (alone or in combination with other biomarkers of tobacco exposure) to distinguish combusted product use (i.e., cigarettes) from non-combusted product use (i.e., smokeless tobacco [SLT] and electronic cigarettes [e-cigarettes]). Previous research has shown when taken as a ratio with its parent compound (anatalline) nicotelline has shown promise in distinguishing SLT use from combusted tobacco use. Therefore, we propose to expand on this existing literature by measuring these compounds in a large sample of exclusive daily SLT users (N=140), exclusive daily cigarette smokers (N= 140), and dual SLT + cigarette users (N=106) to: 1a) Validate anatalline/nicotelline ratio to distinguish exclusive SLT users from exclusive cigarette smokers, and 1b) determine anatalline/nicotelline ratio cut-points to distinguish exclusive SLT, dual SLT + cigarette use, and exclusive cigarette use. In addition, we propose exploring if this biomarker may also be able to differentiate other non-combusted product use, specifically e-cigarettes, from combusted product use. We propose additional specific aims among exclusive e-cigarette users (N= 140), and dual e-cigarette + cigarette users (N= 140): 2a) Measure nicotelline to distinguish exclusive e-cigarette users from exclusive cigarette smokers, and 2b) determine cut-points of nicotelline and ratios of nicotelline-to-traditional tobacco biomarkers (i.e., 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanol [NNAL]) to distinguish exclusive e-cigarette, dual e-cigarette + cigarette use, and exclusive cigarette use. All aims will be evaluated by comparing levels of exposure using nonparametric Kruskal-Wallace analysis of variance (Aim 1a, 2a) and calculating Receiver Operating Curve (ROC) characteristics (Aim 1b, 2b) to determine cut-points for distinguishing different tobacco product use. Based on biospecimen availability online, these specimens should be available in sufficient quantities. Given the diversity of tobacco products and the different patterns of product use, new tools are needed to help discriminate use of one tobacco product from another and also to identify patterns of polytobacco use.

Title: Exosomal epigenetic biomarkers associated with flavored electronic cigarette use in adults

PI: Dongmei Li PhD, University of Rochester

Abstract: This proposed project addresses two scientific interest areas in Food and Drug Administration, Center for Tobacco Products research: 1) Utilize both blood and urine specimens to analyze biomarkers of tobacco exposure not currently measured by other national studies; 2) Examine differences in exosomal epigenetic biomarkers associated with exposure to tobacco products. Smoking is the leading cause of preventable death and increases risks for many cancers and chronic diseases such as lung disease, stroke, heart disease, and diabetes. E-cigarette, a handheld electronic device simulating the feeling of tobacco smoking, gains global popularity during the past few years especially in youth and young adults, largely due to various e-liquid flavors. However, the health risks of e-cigarette use, especially long-term health risks, are unclear. E-liquid usually contains propylene glycol and/or vegetable glycerin as well as nicotine and flavoring chemicals. Our previous experimental studies on lung epithelial cells and monocytes exposed to different flavoring chemicals or e-cigarette flavors without nicotine have shown different cytotoxicity. Our preliminary data showed that there were significant differences in exosomal epigenetic biomarkers (microRNAs and long non-coding RNAs) between non-users and e-cigarette users using human plasma samples. However, how e-liquid flavors (flavoring chemicals) lead to the changes in exosomal epigenetic biomarkers during the e-cigarette initiation, exposure, and cessation is largely unknown. Considering the crucial regulatory functions of microRNAs and long non-coding RNAs and their association with diseases, it is critical to evaluate their changes and associated biological pathways during the flavored e-cigarette initiation, exposure and cessation to help understand health risks associated with e-cigarette use. The overarching goal of the proposed study is to identify exosomal epigenetic biomarkers (including microRNAs and long non-coding RNAs) associated with flavored e-cigarettes. We have requested both longitudinal urine specimens (PATH Wave 1 study conducted from 2013 to 2014 and Wave 2 study conducted from 2014 to 2015) and cross-sectional blood specimen (PATH Wave 1 study) from Population Assessment of Tobacco and Health (PATH) Study biorepositories. We will link these biospecimens with PATH survey data through unique subject IDs. To achieve our goal, we will examine both blood and urinary exosomal epigenetic biomarkers (microRNAs and long non-coding RNAs) and associated biological pathways related to flavored e-cigarettes use (such as fruit flavor) (Aim 1), as well as the within-subject alterations in exosomal epigenetic biomarkers and associated biological pathways during the e-cigarette initiation and cessation (Aim 2). Outcomes for Regulatory Science: Assessment of health risks of the flavored e-cigarette through identification of microRNAs and long non-coding RNAs associated with e-cigarette exposure from PATH Wave 1 and Wave 2 blood and urine specimens will provide crucial information on relative toxicity of e-cigarette flavorings, which would provide evidence to support the FDA’s regulatory efforts.