Effect of curcumin on expression of mucin 5AC in human lung squamous cell carcinoma cell line NCI-H292 and its mechanism

TANG Lingling; NI Zhenhua; CHENG Qingge; MENG Ziyu; WANG Xiongbiao

doi:10.3969/j.issn.1002-266X.2019.02.008

Abstract：Objective To investigate the effect of curcumin on the expression of mucin 5AC ( MUC5AC) in human lung squamous cell carcinoma cell line NCI-H292 and its mechanism. Methods The cells were divided into two groups:the curcumin group and control group, and curcumin and DMSO were added, respectively. The expression levels of MUC5 AC, forkhead box protein A2 ( FOXA2) and phosphorylation signal transduction and activator protein 6 ( p-STAT6) were detected by Western blotting; the cells were divided into two groups: FOXA2 siRNA group and NC-siRNA group, which were transfected with FOXA2 siRNA and negative-siRNA for 24 h, respectively. The expression levels of MUC5 AC and FOXA2 were detected by Western blotting. The transfected two groups were treated with curcumin and the same amount of DMSO for 48 h, respectively, and we detected MUC5 AC by Western blotting. The cells were divided into the control group, inhibitor group and curcumin group, which were treated with DMSO, STAT6 inhibitor Kaempferol, and curcumin for48 h, respectively. The FOXA2 mRNA was detected by RT-PCR. Results Compared with the control group, the expression of MUC5 AC and p-STAT6 decreased and the expression of FOXA2 increased in the curcumin group ( all P < 0. 01) .Compared with the NC-siRNA group, FOXA2 expression level decreased and MUC5 AC protein expression increased in the FOXA2 siRNA group ( both P < 0. 01) . Compared with the cells treated with DMSO, the expression of MUC5 AC decreased after adding curcumin in the NC-siRNA group and FOXA2 siRNA group ( all P < 0. 01) . The relative expression of FOXA2 mRNA was as follows: control group < inhibitor group < curcumin group ( P < 0. 01) . Conclusion Curcumin up-regulates the FOXA2 protein expression by inhibiting STAT6 phosphorylation into the nucleus, thereby inhibiting the secretion of MUC5 AC by NCI-H292 cells.