Abstract: Objective To explore the mutual effect of proinflammatory factor tumor necrosis factor(TNF)-α and cigarette smoke extract(CSE) in the induction of mucin 5AC in BEAS-2B human airway epithelial cells．Methods The BEAS-2B cells were transfected with nuclear factor(NF)-κB decoy oligonucleotides(ODNs) or transfected with NF-κB scrambled ODNs as negative control，then treated with TNF-α，CSE，and TNF-α plus CSE，respectively． The expression of phosphorylated epidermal growth factor receptor(p-EGFR)，mucin 5AC peotein production and gene expression were detected by Western blot，ELISA and RT-PCR，respectively．Results It was showed an obvious increasing of p-EGFR protein production in scrambled ODNs transfected cells exposed to stimuli，with elevation of MUC5AC protein production and mRNA expression，and the TNF-α and CSE co-incubated groups were much higher than single TNF-α or CSE stimulated group(P<0.05)．The relative content of p-EGFR protein，MUC5AC mRNA，and MUC5AC protein in the TNF-α and CSE coincubated groups were 0.74±0.06，0.77±0.10，and 0.72±0.03，respectively，compared with 0.58±0.08，0.52±0.07，and 0.53±0.11 in CSE-stimulated group and 0.53±0.04，0.58±0.11，0.56±0.05 in TNF-α-induced group，all P<0.05． In NF-κB decoy ODNs transfected cells，TNF-α stimuli revealed an obvious reduction of MUC5AC protein production and gene expression，were 0.35±0.12，and 0.41±0.12，respectively，compared with scrambled ODNs transfected group，P<0.05，but had little effect in CSE group and co-incubated group，which still at a relative high level, were 0.48±0.04，0.49±0.11 and 0.51±0.08，0.48±0.07，respectively，compared with negative control group，P<0.05． Conclusion TNF-α and CSE can synergistically induce mucin 5AC expression in BEAS-2B cells, transcription factor NF-κB plays a critical role in TNF-α induced mucin production but not as so important in CSE stimulated cells.

Key words: Mucins, tumor necrosis factor-alpha, cigarette smoking, NF-kappa B