Figure 2. MT3-MMP expressing WM852 melanoma cells invade readily fibrin but have limited ability to invade collagen type I.

(A) MT1- and MT3-MMP mRNA expression in WM852 cells from nodular melanoma and Bowes cells from superficially spreading melanoma were analyzed by Northern blotting. GAPDH mRNA levels served as an internal standard. (B) The cells were allowed to invade 3D fibrin and type I collagen for 7 d. Quantitative results are expressed as the number of invasive cells per microscopic field (n = 3). The number of invasive cells in fibrin was set to 100%. (C) Light micrographs of fibrin and collagen cross-sections visualize the invasion of WM852 and Bowes cells. GM6001 (10 µM) was added where indicated. White dotted lines mark the surface of the matrix.