# Project 2: E-cigarette Smoke Induced Bladder Carcinogenesis and            Invasive Cancer Development

> **NIH NIH P01** · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · 2022 · $315,238

## Abstract

Project 2 Summary
Tobacco smoke (TS) is a major cause of bladder cancer. In addition to nicotine, the highly addictive stimulant
in TS that provides smokers with instant gratification, TS contains many carcinogens generated during the
curing and burning of tobacco leaves. However, E-cigarettes (E-cigs) were designed to deliver E-cig smoke
(ECS), which comprises only nicotine in aerosolized gas phase solvents. E-cigs do not use tobacco leaves,
and the generation of E-cig smoke (ECS) does not involve burning. Hence, ECS contains only nicotine and the
gas phase solvents. E-cigs are promoted as delivering a TS `high' without the negative effects of TS. Given the
rapid rise in the number of E-cig users, the health effects of ECS—particularly its carcinogenicity—deserves
careful scrutiny. It is well established that during tobacco curing, the nitrosation of nicotine generates tobacco-
specific nitrosamines including carcinogenic N'-nitrosonornicotine (NNN) and 4-(methylnitrosamine)-1-(3-
pyridyl)-1-butanone (NNK). An important factor when investigating the carcinogenicity of ECS is determining
whether nicotine nitrosation can occur in vivo. However, it can be difficult to measure NNN and NNK
concentrations in humans and rodents as both have multiple cytochrome p450s that quickly transform NNK
and NNN into methyldiazohydroxide (MDOH), formaldehyde (FAL), and pyridyl-butyl-derivatives (PBDs). As a
result, the levels of NNK and NNN resulting from nitrosation of inhaled nicotine are very low at any given time.
To circumvent this, we determine nicotine-induced DNA damage, rather than directly measuring the nicotine
metabolites NNK and NNN. With our novel approach, it should be possible to detect DNA damage induced by
the NNK and NNN metabolites, given that it takes hours to days for mammalian cells to repair DNA damage.
Our recent results show that in human urothelial cells (HUCs), nicotine treatment: 1) induces mutagenic O6-
methyl-deoxyguanosine and cyclic 1,N2-gamma-hydroxy-propano-dG adducts; 2) reduces DNA repair capacity; 3)
downregulates DNA repair genes; and 4) enhances HUC's mutation and tumorigenic transformation. We also
found that ECS induces DNA adducts in mouse bladder mucosa which cross react with PdG and O6-medG
antibodies. Based on these results, we hypothesize that ECS is a bladder carcinogen that causes
carcinogenesis through nitrosation of nicotine into NNN and NNK, and the metabolites can, in turn, damage
DNA, modify DNA repair proteins, and enhance mutation susceptibility and tumorigenic transformation. We will
test this hypothesis and determine the molecular mechanisms by using mouse models to determine: 1) ECS's
effect on DNA repair in mouse bladder mucosa; 2) the chemical nature of ECS-induced DNA adducts; 3) the
ECS-induced molecular alterations in mouse bladder tissues; and 4) the ECS bladder carcinogenicity. These
studies will help dispel the unsubstantiated claim that ECS is safe and will discourage individuals from smoking
E-ci...

## Key facts

- **NIH application ID:** 10455730
- **Project number:** 5P01CA165980-09
- **Recipient organization:** NEW YORK UNIVERSITY SCHOOL OF MEDICINE
- **Principal Investigator:** Eric Moon-shong M. TANG
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $315,238
- **Award type:** 5
- **Project period:** 2013-09-12 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10455730

## Citation

> US National Institutes of Health, RePORTER application 10455730, Project 2: E-cigarette Smoke Induced Bladder Carcinogenesis and            Invasive Cancer Development (5P01CA165980-09). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10455730. Licensed CC0.

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