Figure 1.

CXCL1 knockdown in cancer cell lines inhibits invasion and tube formation. A, Western blot and real-time RT-PCR analyses of CXCL1 in human cancer cell lines T24 (bladder), DU145 and PC3 (prostate). B, Western blot and real-time RT-PCR analyses of CXCR2 in human cancer cell lines T24, DU145 and PC3, and HEK293T (human embryonic kidney cells). Parental HEK293T cells and HEK293T cells overexpressing CXCR2 were used as negative and positive controls, respectively. C, T24 and PC3 cells were stably knockdown by shRNA targeting CXCL1 (T24-CXCL1-KD4&8 and PC3-CXCL1^KD7) or scrambled control (T24-shSCR and PC3-shSCR), while DU145 cells were stably transfected with empty vector (DU145-Empty) or CXCL1 expression plasmid (DU145-CXCL1OE3&8). Western blot analysis demonstrated altered CXCL1 expression in the two selected T24-CXCL1 clones 4 and 8, the two selected DU145 clones 3 and 8 and the one PC3 clone 7. D, CXCL1 ELISA assay confirmed altered secretion of CXCL1 in line with the above western blot analysis. E, T24 cells (T24-shSCR, T24-CXCL1-KD4&8), DU145 cells (DU145-Empty, DU145-CXCL1-OE3&8, PC3 cells (PC3-shSCR, PC3-CXCL1-KD7) were subjected to in vitro migration and invasion assays. Data are average percent of control and SDs of three independent experiments conducted in triplicate. Overexpression of CXCL1 in DU145 cells was noted to correspond with an increase in invasive potential, while silencing of CXCL1 in T24 and PC3 cells resulted in a reduced invasive potential. Data from one representative experiment are presented as mean ± SD, *, p < 0.05; **, p < 0.01 and ***, p < 0.001. All western blot experiments were performed in triplicate, representative experiment was shown.