Fig. 8

ERα-36 and STAT3 bind to MMP2 and MMP9 promoter and mediate MMP2 and MMP9 expression in response to IL-6. a, Schematic of the − 904 MMP2 promoter, containing GAS element was linked to a luciferase reporter. Mutation or truncations that remove the GAS element. -904 MMP2 promoter, a truncated promoter − 828 or the − 904 MMP2 promoter with mutations in GAS. b, Schematic of the − 4138 MMP9 promoter, containing GAS element was linked to a luciferase reporter. Mutation or truncations that remove the GAS box element. -4138 MMP9 promoter, a truncated promoter − 3876 or the − 4138 MMP9 promoter with mutations in GAS. c, MDA-MB-231 cells were transfected with the wild-type − 904 MMP2 promoter, or a truncated promoter − 828 or the − 904 MMP2 promoter with mutations in GAS, and transfected with ERα-36 or STAT3 48 h. Then the luciferase reporter assays was used to test the transcriptional of MMP2. d, MDA-MB-231 cells were transfected with the wild-type − 4138 MMP9 promoter, or a truncated promoter − 3876 or the-4138 MMP9 promoter with mutations in GAS, and transfected with ERα-36 or STAT3 48 h. Then the luciferase reporter assays was used to test the transactivity of MMP9. e and f, MDA-MB-231 cells were transiently transfected with a STAT3 ERα-36/STAT3 or a control vector (pCDNA3.1) 48 h, and ChIP assays were performed as described in Materials and Methods with primers for sequences associated with the genes for MMP2 and MMP9. Sheared DNA/protein complexes were immunoprecipitated by using an anti-Myc-STAT3 Ab. Then, PCR was carried out to detect the endogenous GAS regions in immunoprecipitated chromatin fragments. The amount of DNA in each sample (2%input) is shown at the second land. Immunoprecipitations were performed without primary antibody (No Ab) as a control and IgG as a negative control