Identification of nicotinic acetylcholine receptor subunits in different lung cancer cell lines and the inhibitory effect of alpha-conotoxin TxID on lung cancer cell growth.

Lung cancer is an aggressive tumor with high incidence and mortality rate. There was growing evidence supporting that nicotinic acetylcholine receptors (nAChRs) play vital role inlung cancer development. In this study, the expression of α3, α4, α5, α6, α7, α9, α10, β2, β3, β4 nAChR subunits on protein and mRNA level were studied in A549, NCI-H1299, NCI-H1688, DMS114 and normal human embryonic lung fibroblast (HEL) cell lines by real-time quantitative PCR (qPCR) and Western blot assay respectively. The results indicated that most of these nAChR subunits were expressed in these five cell lines. Compared with normal cells, the expression of α3 and β4 nAChR subunits were upregulated in A549 and NCI-H1299. Thus, we treated A549 and NCI-H1299 with an antagonist α-conotoxin TxID which potently and selectively blocks α3β4 nAChRs. TxID treatment could inhibit A549 and NCI-H1299 cell growth and enhance the inhibitory effect of adriamycin when treated simultaneously. To sum up, our study identified the expression of nAChR subunits in different lung cells and the anti-tumor effect of α-conotoxin TxID, which may provide novel strategies for lung cancer therapy.