Submitted to: Lung Cancer
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2013
Publication Date: 9/29/2013
Citation: Aizawa, K., Liu, C., Veeramachaneni, S., Hu, K., Smith, D.E., Wang, X. 2013. Development of ferret as a human lung cancer model by injecting4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Lung Cancer. doi:10.1016/j.lungcan.2013.09.012. Interpretive Summary: Development of new animal lung cancer models that are relevant to human lung cancer is important for lung cancer research. In the present study, we demonstrated that ferrets (Mustela putorius furo) exposed to a tobacco carcinogen (NNK) developed both precancerous lesions and lung cancer, which are commonly seen in humans. The development of lung cancer in the ferrets by injecting NNK alone provides a simple and highly relevant non-rodent model for studying biomarkers/molecular targets for the prevention, detection and treatment of lung cancer in humans.
Technical Abstract: Development of new animal lung cancer models that are relevant to human lung carcinogenesis is important for lung cancer research. Previously we have shown the induction of lung tumor in ferrets (Mustela putorius furo) exposed to both tobacco smoke and a tobacco carcinogen (4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone, NNK). In the present study, we investigated whether NNK treatment alone induces both preneoplastic and neoplastic lesions in the lungs of ferrets. Methods: We exposed ferrets to NNK by i.p. injection of NNK (50 mg/kg BW) once a month for four consecutive months and then followed up for 24, 26 and 32 weeks. The incidences of pulmonary pre-neoplastic and neoplastic lesions were assessed by histopathological examination. The expressions of7 nicotinic acetylcholine receptor (7 nAChR, which has been shown to promote lung carcinogenesis)and its related molecular biomarkers in lungs were examined by immunohistochemistry and/or Western blotting analysis. Results: Ferrets exposed to NNK alone developed both preneoplastic lesions (squamous metaplasia, dysplasia and atypical adenomatous hyperplasia) and tumors (squamous cell carcinoma, adenocarcinoma and adenosquamous carcinoma), which are commonly seen in humans. The incidence of tumor induced by NNK was time-dependent in the ferrets (16.7%, 40.0% and 66.7% for 24, 26 and 32 weeks, respectively). 7 nAChR is highly expressed in the ferret bronchial/bronchiolar epithelial cells, and alve macrophages in ferrets exposed to NNK, and in both squamous cell carcinoma and adenocarcinoma ofthe ferrets. In addition, we observed the tendency for an increase in phospho-ERK and cyclin D1 proteinlevels (p = 0.081 and 0.080, respectively) in the lungs of ferrets exposed to NNK. Conclusion: The development of both preneo plastic and neoplastic lesions in ferret lungs by injecting NNK alone provides a simple and highly relevant non-rodent model for studying biomarkers/molecular targets for the prevention, detection and treatment of lung carcinogenesis in humans.