Figure 6
Plumbagin suppresses invasion in breast and gastric cancer cells. A, MDA-MB-231 (2 × 105 cells) were seeded in the top-chamber of the Matrigel. After pre-incubation with or without plumbagin (5 μM) for 6 h, transwell chambers were then placed into the wells of a 24-well plate, in which we had added either the basal medium only or basal medium containing 100 ng/mL CXCL12 for 24 h. After incubation, they were assessed for cell invasion as described in Materials and Methods. Columns indicate mean percentage of invaded cells; bars, S.E. *, P < 0.05. B, AGS (2 × 105 cells) were seeded in the top-chamber of the Matrigel. After pre-incubation with or without plumbagin (5 μM) for 6 h, transwell chambers were then placed into the wells of a 24-well plate, in which we had added either the basal medium only or basal medium containing 100 ng/mL CXCL12 for 24 h. After incubation, the chambers were assessed for cell invasion as described in Materials and Methods. Columns indicate mean percentage of invaded cells; bars, S.E. *, P < 0.05. Representative results of three independent experiments are shown. C, Plumbagin suppresses expression of CXCR4 mRNA expression in gastric cancer cells. AGS cells were treated with 5 μM plumbagin for indicated times. Total RNA was isolated and analyzed by RT-PCR assay as described in Materials and Methods. 18S was shown to equal loading of total RNA. Representative results of three independent experiments are shown. D, Plumbagin suppresses expression of CXCR4 protein expression in gastric cancer cells. Cells were incubated with 5 μM plumbagin for indicated times. Whole-cell extracts were prepared and analyzed by Western blot analysis using antibodies against CXCR4. The same blots were stripped and reprobed with β-actin antibody to show equal protein loading. Representative results of three independent experiments are shown.