Regulation of the "neuronal" nicotinic acetylcholine receptors (nAChRs) is implicated in both tobacco addiction and smoking-dependent tumor promotion. Some of these effects are caused by the tobacco-derived N-nitrosamines, which are carcinogenic compounds that avidly bind to nAChRs. However, the functional effects of these drugs on specific nAChR subtypes are largely unknown. By using patch-cla...

The incidence of lung adenocarcinoma has been remarkably increasing in recent years due to the introduction of filter cigarettes and secondary-hand smoking because the people are more exposed to higher amounts of nitrogen oxides, especially 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), which is widely applied in animal model of lung tumors. In NNK-induced lung tumors, genetic mutation, c...

Tumor-associated macrophages (TAMs) promote tumorigenesis because of their proangiogenic and immune-suppressive functions. Here, we report that butylated hydroxyanisole (BHA) blocks occurrence of tumor associated macrophages (TAMs) in tobacco smoke carcinogen-induced lung tumorigenesis. Continuous administration of butylated hydroxyanisole (BHA), a ROS inhibitor, before or after NNK treatment s...

Cigarette smoking is a risk factor for pancreatic cancer. It is suggested that 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific nitrosamine, mediates the carcinogenic action of cigarette smoking by promoting cancer growth. In the present study, we show that smoking, HIF-1α expression and β2-adrenogenic receptor (β2-AR) expression are negatively correlated with the overal...

Tobacco smoking is the only known etiologic agent that causes pancreatic cancer. The tobacco-specific nitrosamine 4-(methylnitrosamino)-I-(3-pyridyl)-1-butanone (NNK) is a potent carcinogen in laboratory rodents that, independent of the route of administration, induces primarily lung adenocarcinoma (1). When administered in drinking water, NNK and its metabolite 4-(methy1nitrosamino)-1(3-pyridy...

Critical to mechanisms of chemical carcinogenesis and the design of chemopreventive strategies is whether procarcinogen bioactivation in an extrahepatic target tissue (e.g., the lung) is essential for tumor formation. This study aims to develop a mouse model capable of revealing the role of pulmonary microsomal cytochrome P450 (P450)-mediated metabolic activation in xenobiotic-induced lung canc...

We previously reported the chemopreventive potential of kava against 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)- and benzo(a)pyrene (BaP)-induced lung tumorigenesis in A/J mice during the initiation and postinitiation stages. In this study, we investigated the tumorigenesis-stage specificity of kava, the potential active compounds, and the underlying mechanisms in NNK-induced lung tum...

Introduction The TSNA NNK is a rodent carcinogen likely to play an important role in smoking-induced lung cancer (1). Metabolism of NNK can proceed directly via cytochrome P450 activation to -hydroxyNNK or formation of NNAL and subsequent hydroxylation to -hydroxyNNAL, resulting in formation of promutagenic DNA adducts. NNAL can be detoxified by conjugation to NNAL-Gluc. NNAL and NNAL-Gluc in b...

A mixture of dietary benzyl isothiocyanate (BITC) and 2-phenethyl isothiocyanate (PEITC) inhibits lung tumorigenesis by a mixture of benzo[a]pyrene (B[a]P) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in A/J mice. Previous studies indicated that inhibition of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) releasing DNA adducts of NNK by PEITC in the lung was responsible for inhibition of ...

The tobacco-specific nitrosamine, 4-(methylnitrosamino)-l-(3-pyridyl)1-butanone (NNK), is considered to play an important role in the induc tion of lung cancer in tobacco users. In rats treated with [5--'H]NNK, 20 to 40% of the tritium bound to hemoglobin (Hb) is released by base hydrol ysis as 4-hydroxy-l-(3-pyridyl)-l-butanone (HPB). This HPB-releasing adduct has been quantified in tobacco us...