Figure 4. Migration and invasion by iKD-USP9X-BxPC3 cells following knockdown of USP9X. (A) A migration assay was performed as described in the Materials and Methods. iKD-USP9X-BxPC3 cells were grown in the absence or presence (1 µg/mL) of Dox for 48 h and then transferred onto uncoated porous membranes in serum-free medium. Cells were allowed to migrate through the membrane, toward serum-containing medium, for 24 h, before being fixed, stained and counted. The values presented are averages of cells in 14 random, 6.25 mm² fields. Error bars represent standard error of the mean. The Student t test was used to evaluate statistical significance. This experiment was repeated two additional times with similar results. (B) Similarly, invasion assays were performed as described in the Materials and Methods. Membranes coated with Matrigel were used along with uncoated membranes. Stained cells were counted in 18 random, 6.25 mm² fields. The bar graph depicts the percentage of invasion (average number of cells per field observed and standard error of the mean for the invasion membranes divided by the average number of cells per field observed on the uncoated membranes). Error bars represent conversion of standard error of the mean. The Student t test was used to test average counts per field for significant difference. This experiment was repeated two additional times, with similar results.