Figure 10.

Effect of hSec10 overexpression on tubulogenesis. (a and b, insets) Nomarski imaging of mature hSec10 overexpressing (a, inset) and control (b, inset) cell cysts grown for 10 d in collagen again showed that the cysts composed of hSec10 overexpressing cells were larger than cysts composed of control cells. (a and b) HGF-induced stimulation, for 48 h, of mature cysts revealed greater numbers of tubules per cyst in the cysts composed of hSec10 overexpressing (a) versus control cells (b). (c) Quantitation of the number of tubules formed per cyst, as measured at the level of greatest cyst diameter, revealed increased tubulogenesis in all the clones of hSec10 overexpressing versus control cell cysts. Similar effects were seen as early as 6 and 12 h after addition of HGF (Lipschutz and Mostov, unpublished observations), indicating that the increase in tubule number was not simply a result of enhanced tubular lumen formation, which is a later event (Pollack et al., 1998). a and b were taken at equal magnification. Bar, 30 μm.