PRL-3 engages the focal adhesion pathway in triple-negative breast cancer cells to alter actin structure and substrate adhesion properties critical for cell migration and invasion.

•Elevated expression of PRL-3 correlates with Src level in human breast cancer.•AMPI-109 or loss of PRL-3 reduces Src and ERK activation in TNBC cells.•AMPI-109 or loss of PRL-3 decreases RhoA, Rac1/2/3 levels in TNBC cells.•F-actin networks are disrupted in TNBC cells with PRL-3 knock down.•PRL-3 drives TNBC invasion through laminin via an MMP-10 dependent mechanism.