Non-neuronal alpha7 nicotinic receptor regulates cell siganaling in human mammary epithelial cell lines

ESANDI, M.C.; MAYORA JUSTEL, C.L.; CHRESTI, J.F.; BOUZAT, C.; BRUZZONE, A.

Mar del Plata

Congreso; Reunión Conjunta de Sociedades de Biociencias 2018; 2018

Nicotinic acetylcholine receptors (nAChRs) constitute a heterologous family of ion channels that mediate fast synaptic transmission in neurons. They are also expressed in numerous cell types, where they have other functions well beyond neurotransmission such as cell proliferation or migration. Nicotine has been implicated in cancer progression by activation of nAChRs, mainly through pentameric alpha7 and alpha9 receptors. Here we examine the possible downstream signalling pathway of the alpha7 nAChR in human breast cell lines. For this purpose, MCF-10A, MCF-7, MDA-MB-231 and T47D cells were used.By using RT-PCR and Western Blot, we determined the expression of alpha7 nAChR subunit in all cell lines. No expression of the alpha9 nAChR subunit was detected.Relative quantitation (qPCR) demonstrated up-regultation of the alpha7 subunit expression in MCF-7 cells after 48 hr incubation with nicotine (10muM). Kinetics of alpha7 activation by specific agonist PNU-282987 demonstrated an increase of ERK1/2 and Akt phosphorylation, in all cell lines, measured by Western blot. Moreover, PNU-282987 stimulated significantly MCF-7 cell proliferation, and this effect was reversed by the alpha-7 specifici antagonist bungarotoxin. These results highlight the pathophysiological role of alpha7 receptors in promoting cell growth and intracellular signaling and provide a framework for the development of new drugs that specifically target these receptors.