Fig. 5. Recombinant stromelysin-1 induces branching morphogenesis of primary
mammary organoids. (A) Dose response to rStr1. Mean±s.d. of three
independent experiments is shown. (B) GM6001 inhibits rStr1-induced branching.
rStr1 (1µg/ml) induced-branching morphogenesis compared with the control
(**P<0.01). Control samples were treated with trypsin
and soy bean trypsin inhibitor (SBTI), GM6001,
(***P
0.001). The means±s.d. of three
independent experiments are shown. To calculate the branching index, control
values were equated to 1. (C) Appearance of organoids in collagen I gels after
6 days with or without Str1 and GM6001 treatments. (D) Gelatin zymogram of
conditioned media of organoids treated with buffer (Control, C), or different
concentration of rStr1, with or without GM6001 (GM6) or trypsin+SBTI (T/S).
Note the activation of gelatinase B in the presence of rStr1. This activation
is inhibited in the presence of GM6001, as expected. Treatment with
trypsin+SBTI (T/S) did not activate gelatinase B. Scale bars: 200 µm in
C.