Detection of NNK-Induced DNA Adduct Formation in Human Air-Liquid-Interface Airway Tissue Models
Principal Investigator: Xuefei Cao and Xin Fu
Funding Mechanism: Internal FDA
ID number: E07604.01
Award Date: 10/22/2015
Institution: National Center for Toxicological Research (NCTR)
The tobacco specific nitrosamine 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone (NNK) is one of the major carcinogens found in tobacco smoke; it causes gene mutations in vivo and in vitro and cancer in rodents. The aims of this six-month pilot study are: (1) to develop a liquid chromatography-mass spectrometry method to detect NNK-induced DNA adducts, and (2) to establish procedures to measure DNA damage using the Comet assay in in vitro human respiratory tract tissue models. An air-liquid-interface (ALI) model using well-differentiated primary human bronchial epithelial cells will be compared with single-layer human lung cancer cells and normal human bronchial epithelial cells. These data will be compared to in vivo adduct formation and DNA damage in rats and humans. This pilot study may guide future studies that compare NNK-induced toxicity outcomes in vitro with the findings from existing in vivo studies involving different NNK doses. Pilot study results may provide methodology to develop new in vitro respiratory tissue models in evaluations of the cancer-causing and gene mutation-related effects of inhaled carcinogens, which will be a new approach in the toxicological evaluation of tobacco products.