Decreased migration and invasion in LRP1 knockdown U87 cells were rescued by MMP2 and MMP9 overexpression. LRP1 minireceptor mLRP4, MMP2, or MMP9 expression vector was co-transfected with LRP1 siRNA into U87 cells and cellular migration and invasion were analyzed. A, Negative control or LRP1 siRNA, with or without mLRP4 were co-transfected into U87 cells. mRNA levels of MMP2 and MMP9 were quantified by real-time PCR. B, Invasion assay was conducted after pcDNA, mLRP4, MMP2, or MMP9 was co-transfected with LRP1 siRNA. C, Two-dimensional migration assay was performed after pcDNA, mLRP4, MMP2, or MMP9 was co-transfected with or without LRP1 siRNA. Bar indicates 100 μm. Values are the average of triple determinations with the S.D. indicated by error bars. *p < 0.05, **p < 0.01