Role of NGX6 in Wnt/β-catenin signaling pathway in colon cancer

Objective To explore the role of nasopharyngeal carinoma associated gene 6(NGX6) in Wnt/β-catenin signaling pathway and to identify whether there is feedback regulation between NGX6 and Wnt signal pathway once the Wnt signal is blocked.Methods pCMV-myc-NGX6 and pCMV-myc were transfected to colon cancer cell line SW62O and the expression of downstream target molecules of Wnt/β-catenin signaling pathway such as c-myc,cyclinD1,and c-jun were detected by Western blot.The eukaryotic expression vector pcDNA3.1(+)-LEF1DN(without N-terminal β-catenin binding domain) was constructed to inhibit Wnt signaling pathway,and the effect was confirmed by Western blot and TCF-4 luciferase report system.The mRNA expression of NGX6 in SW620 was detected by RT-PCR after pcDNA3.1(+)-LEF1DN transient transfection.Results The expression of above molecules were obviously down-regulated by NGX6 transient transfection in SW620.The eukaryotic expression vector pcDNA3.1(+)-LEF1DN showed an inhibitory effect on Wnt/β-catenin signaling pathway.The mRNA expression of NGX6 in SW620 was up-regulated after pcDNA3.1(+)-LEF1DN transient transfection.Conclusion NGX6 could inhibit the expression of Wnt signaling downstream target genes,which maybe related to the potential feedback regulation between NGX6 and Wnt signal pathway.