Fig. 5.

CTHRC1 transcriptionally modulates MMP7 expression through c-JUN. a CTHRC1 overexpression increased MMP7 promoter activity. b MMP7 promoter activity was inhibited when CTHRC1 was downregulated. c The MMP7 promoter region was cloned as three fragments (P1 to P3). d Transactivating activity of CTHRC1 on serial MMP7 promoter fragments, as indicated in NCI-H1975 cells. CTHRC1 overexpression enhanced promoter activity in P1 and P2. CTHRC1 knockdown weakened promoter activity in P1 and P2. e Schematic illustration showing the PCR-amplified fragments of the MMP7 promoter. f Regions of the MMP7 promoter that were physically associated with CTHRC1 were analysed in a ChIP assay. IgG was used as a negative control. PCR amplification indicated the binding efficiency to region 2 was significantly decreased in NCI-H1975-AP-1/c-Jun siRNA cells. g CTHRC1 overexpression upregulated the expression of MMP7, and the upregulation of MMP7 was abolished when c-JUN was knocked down as measured by western blot. Representative bands are shown. h The western blot results were semi-quantified and are shown in bar graph form. Experiments had been repeated three times. *p < 0.05, **p < 0.01