Figure 7.

CD44-dependent cell-mediated degradation of collagen IV. Twenty-four-well plates were coated with ³H-labeled collagen type IV (5000 cpm/well), and TA3 and MC transfectants were seeded onto the plates at 2 × 10⁵ cell/well. Following a 16 hr incubation at 37°C, cell culture supernatants were recovered, centrifuged, and the radiolabel quantified from one-fifth of each supernatant in a β-counter. Cells were either untreated or preincubated with antibody, MMP-inhibitor peptides, or phenantroline as described in Materials and Methods. (A) Collagen IV degradation by MCwt and MCCD44 transfectants pretreated or not with MMP-3 inhibitor peptide, MMP-inhibitor peptide I, anti-MMP-2, and anti-MMP-9 mAb; (B) TA3c and TA3sCD44v6-10 cells pretreated or not with 1-10 phenanthroline, aprotinin, anti-ICAM mAb HB233, blocking anti-CD44 mAb KM201, and weakly blocking anti-CD44 mAb IM7.8. (C) Collagen degradation by two independent TA3c and TA3sCD44v6-10 isolates transfected with scrambled (vector) or antisense MMP-9 cDNA. The results are expressed as the mean ± s.d. of triplicate values.