MAPK signaling pathways are involved in SDF-1-induced ICAM-1 promoter activity. (A) ICAM-1 p537-Luc activity was determined in DLD-1 cells pretreated with vehicle (DMSO), or PD98059 (PD), SP600125 (SP), and SB203580 (SB) individually for 1 h, or transfected with control shRNA (sh-CL), or a specific shRNAs of ERK (sh-ERK), JNK (sh-JNK) or p38 (sh-p38), and then stimulated with 10 ng/mL SDF-1 for 4 h. (B) Sp1, (C) C/EBP-β and (D) NF-κB p65 activation were determined by TF ELISA assays in DLD-1 cells pretreated with vehicle (DMSO), or PD98059 (PD), SP600125 (SP) and SB203580 (SB) individually for 1 h, or transfected with sh-CL, or sh-ERK, sh-JNK or sh-p38, and were then stimulated with SDF-1 for 2 h. All bar graphs represent multiple increases of CL DLD-1 cells, mean ± SEM. *P < 0.05 versus CL. #P < 0.05 versus vehicle control (DMSO) with SDF-1 stimulation. (E) DLD-1 cells were kept as CL or stimulated with SDF-1 for the times indicated, and the IκB protein expression was determined by Western blot analysis.