(A) MSC were transiently transfected with pcDNA3.1 (Mock, white bars), a plasmid encoding full length MT1-MMP (Wt, black bars), or a plasmid encoding for a cytoplasmic domain-deleted form of MT1-MMP (Δ-cyto, grey bars). Cells were then cultured under normoxic culture conditions, total RNA was extracted, and qRT-PCR was used to assess 3BP2 gene expression. (B) Gelatin zymography of the conditioned media was used to demonstrate efficient cell surface targeting of the respective Wt and Δ-cyto MT1-MMP recombinant proteins and subsequent ability to retain extracellular catalytic functions and to activate the secreted latent proMMP-2 into active MMP-2. (C) Cell lysates were isolated, western blotting and immunodetection was performed with antibodies recognizing the MT1-MMP catalytic or cytoplasmic domain, anti-3BP2 and anti-GAPDH as described in the Methods section. Values are means of two independent experiments, each performed in triplicates (*p<0.05 versus Wt-MT1-MMP control); Bars, ±SD.