Figure 2

Integrin β1 mediates PRL-3-induced cell motility and invasion. (A) LoVo-P cells were treated with siRNA specific for integrin β1 or control. Seventy-two hours after transfection, cells were harvested. Equal amount of protein lysates (50 μg of protein) was analyzed for integrin β1 protein expression and RNA was extracted for RT-PCR. (B) and (C) Integrin β1 is required for PRL-3-induced cell motility and invasion. Cells were transfected with indicated siRNAs as in (A). Seventy-two hours after transfection, cells were analyzed for their motility and invasion with the use of transwell chambers. Cells were suspended in serum-free medium and loaded at a density of 2.5 × 10⁴ to an insert of a transwell chamber, and those migrating or invading to the underside of filtera were stained and counted after 24 h (B, motility assay) or 48 h (C, invasion assay). Top panel: Representative illustrations for motility and invasion assays (original magnification, × 200). Bottom panel: Quantification of migrating and invasive cells. Values were the total number of stained cells. The experiments were repeated at least three times independently. Error bars represent standard errors of the mean value (*, P < 0.05).