Knock-down of endogenous PRL-3 inhibits cell migration, invasion, and xenograft tumor growth of A2780 ovarian cancer cells. (A) Human ovarian cancer cells A2780 were transfected with the scrambled control vector or PRL-3 specific shRNA. Stable cell lines (A2780 Vector, A2780 PRL-3 KD-22 and A2780 PRL-3 KD-S3) were harvested and the mRNA levels of PRLs-1, -2, and -3 were analyzed by semi-quantitative RT-PCR using PRL isoform-specific primers. GAPDH mRNA served as a loading control. (B) PRL-3 protein levels in A2780 vector, A2780 PRL-3 KD-22 and A2780 PRL-3 KD-S3 were determined by western blot using PRL-3 specific antibody. GADPH was used as a control for the western blot assay. (C) Cell migration was analyzed using a standard Transwell assay. After 24 hours incubation, cells that migrated to the lower chamber were fixed, stained, and counted using a light microscope. The relative migration rate of triplicate samples are shown (mean ± SD, Student’s t-test, *p < 0.05). (D) Matrigel in vitro invasion assays were performed as described in the Materials and Methods section. The relative migration rate of triplicate samples are shown (mean ± SD, Student’s t-test, *p < 0.05).