Figure 5

Omeprazole and TCDD decrease CXCR4 and MMP-9. (a) CXCR4 mRNA and protein. MDA-MB-231 cells were treated with DMSO, omeprazole or TCDD and transfected with siCtl (control) or si AHR, and mRNA and protein levels were determined as described in the Methods. (b) Effects on MMP-9. Cells were treated with DMSO, TCDD or omeprazole, and MMP-9 activity (zymography) and MMP-9 mRNA levels (in cells transfected with siCtl or siAHR) were determined as outlined in the Methods. (c) CXCR4 promoter activity. MDA-MB-231 cells were transfected with CXCR4-(-1121 to +95)luc and either cotransfected with siCtl and siAHR or treated with 3′,4′-dimethoxy-α-naphthoflavone and luciferase activity determined as outlined in the Methods. (d) Silencing of CXCR4. Cells were transfected with siCtl or siCXCR4 and effects on cancer cell invasion and CXCR4 expression were determined as outlined in the Methods. Results (a-d) are means ± SE for at least 3 experiments and significant (p < 0.05) decrease (*) or rescue (**) is indicated.