Effect of signal inhibition on cell morphology.

Cells were cultured in serum-free medium in the presence of FN. Cells were pretreated with inhibitors for 1 hour at 37°C; then PMA (10 ng/mL) was added and culture proceeded for 3 days. (A) Morphologic observation. Cells were visualized and measured by means of phase contrast microscopy at original magnification × 200. Representative fields demonstrating the results of at least 10 separate experiments are shown. (B) Morphologic quantitation. Morphologic assay was carried out by means of a phase contrast microscope (see “Materials and methods”). The cells with PPF were defined as those bearing more than one cytoplasmic process that were at least twice the length of the cell body diameter. SFM indicates serum-free medium; PD, PD98059, an inhibitor of MEK MAPK (upstream of ERK); GFX, GF109203X, an inhibitor of PKC; SB, SB203580, an inhibitor of p38 and JNK; Wort, wortmannin, an inhibitor of PI3K. Graph depicts the means ± SE from at least 10 experiments.