Fig. 9.

DACH1 repressed CXCL8 expression through binding to AP-1 and NF-κB sites of CXCL8 promoter in the presence of the DS domain. a Schematic representation of distinct DACH1 expression vectors and CXCL8 promoter mutants used in luciferase reporter gene assay. b The basal activities of empty vectors and plasmids containing different CXCL8 promoters. c The CXCL8 promoter activity in 293T cells transfected with different DACH1 expression vectors. d Relative luciferase activity of CXCL8 promoter and point mutants in 293T cells with and without steady DACH1 expression. TPA and TNF-α were used to stimulate CXCL8 production. e mRNA level of CXCL8 was detected by real-time PCR in SKLU-vector and SKLU-DACH1 cells under the stimulation of TPA and TNF-α. f mRNA level of CXCL8 was detected by real-time PCR in A549-vector and A549-DACH1 cells under the stimulation of TPA and TNF-α. * p < 0.05; ** p < 0.0001