Fig. 5

TSG101 modulates cell invasion of HT1080 cells in an MMP-9-dependent manner. Cells were transfected with control (con) or MMP-9 siRNA to deplete MMP-9, or with TSG101 (TSG#2) siRNA and control (con) or MMP-9 siRNA to simultaneously deplete TSG101 and MMP-9. a–b. Expression and secretion of MMP-9 in simultaneous TSG101- and MMP-9-depleted cells. Cells were incubated in fresh serum-free medium containing or not 200 nM PMA for 7 h. Cell lysates were analyzed by western blot using the indicated antibodies (a). MMPs in conditioned media were measured using gelatin zymography (b). c–d. Cell invasion of simultaneous TSG101- and MMP-9-depleted cells. Each of the transfected cells was allowed to invade for 18 h (c). Scale bars, 200 μm. Cell invasion through the filter in (c) was quantified (d). Relative invasion activities of the cells transfected with MMP-9 siRNA alone, and TSG101 (TSG#2) siRNA and control (con) or MMP-9 siRNA are expressed as the proportion of infiltration of the cells transfected with control (con) siRNA. The blots, gels, and images shown are representative of three independent experiments. The results shown are the means ± S.D. of three independent experiments. * p < 0.05; **, p < 0.005; ns, not significant, by a Student’s t-test