Nongenomic β estrogen receptors enhance β1 adrenergic signaling induced by the nicotine-derived carcinogen 4-(Methyinitrosamino)-1-(3-Pyridyl)-1-Butanone in human small airway epithelial cells

Women are at higher risk for the development of lung adenocarcinoma than men; however, the mechanisms responsible for this are poorly understood. in lung adenocarcinoma cells, the estrogen receptor beta (ER beta) is the predominating form. We found that 17 beta-estradiol enhanced proliferation of the putative cells of origin of lung adenocarcinoma, small airway epithelial cells (HPLD1), in response to the nicotine-derived nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Reverse-phase protein microarrays combined with Western blotting revealed that NNK induced phosphorylation of ER beta, an effect that involved stimulation of the adrenergic receptors beta 1 (beta 1AR). In transiently transfected cells, beta 1AR coprecipitated with ER beta, which increased with NNK treatment. ER beta enhanced NNK-induced cyclic AMP accumulation as well as G alpha i-mediated mitogen-activated protein kinase/extracetlular signal-regulated kinase (ERK) 1/2 activation. Coexpression of beta 1AR and ER beta activated NNK-mediated ERK1/2 cooperatively. ER beta gene knockdown, as well as coexpression of the dominant negative Ras and Raf, reduced stimulation of ERK1/2 by NNK. Whereas NNK phosphorylated Akt at Thr(308) and Ser(473), ER beta had no effect on this activity. Luciferase reporter assays showed that, in response to NNK, ER6 stimulated transcription of serum responsive element (SRE) but had a very small effect on the activity of estrogen responsive element (ERE). Together, the phosphorylation of ER beta, the dependence on G alpha i proteins, the activation of ERK1/2, and the preferential targeting of SRE over the classic ERE pathway support a role for nongenomic ER beta in the development of smoking-associated lung cancer. This novel cooperation between beta 1AR and ER beta signaling may contribute to the prominence of lung adenocarcinoma in women.