Fig. 5.

STAT1 mediates Topoisomerase inhibitors-promoted CXCL1 expression and cell motility. a Validation of the efficiency of STAT1 knockdown after transfection with different siRNAs for 48 h (upper three panels) or siRNA #2 for 24, 48 and 72 h (lower three panels). b Western blot analysis of CXCL1 expression in cells transfected with STAT1-specific siRNA for 48 h. Cells were treated with VP-16 (20 μM) or CPT-11 (80 μg/ml) for 0.5 h before harvest. c Migration assay of cells transfected with STAT1-specific siRNA. 24 h after transfection, cells were subjected to migration assay for 24 h in the presence of VP-16 (20 μM) or CPT-11 (80 μg/ml). d Western blot of JAK2 and STAT1 phosphorylation and CXCL1 expression in cells pretreated with Fludarabine (100 μM) for 1 h and subsequently treated with VP-16 (20 μM) or CPT-11 (80 μg/ml) for 0.5 h. e Migration assay of cells treated with Fludarabine (100 μM) plus VP-16 (20 μM) or CPT-11 (80 μg/ml) for 24 h