Secretion of proMMP-2 and proMMP-9 after 48 hours incubation of JAR cells, 1st trimester trophoblast cells 6–8 week or 1st trimester trophoblast cells 9–12 week in medium in absence or presence of 8 ng/ml EGF. (A) Representative zymography gels. (B) Bar graph, representing mean ± SEM from 10 independent experiments detecting proMMP-2 (72 kD). (C) Bar graph, representing mean ± SEM from 10 independent experiments detecting proMMP-9 (92 kD). White bars represent control medium of cells without treatment, black bars represent medium from cells with EGF treatment. *P < 0.05 vs. control.