Table 2.

Effect of coculturing, tumour cell-conditioned media and growth factors on myofibroblast differentiation of stromal cells in collagen gels

	% of stromal cells positive for α-smooth muscle actin
Culture conditions	Monolayers	Gels
10% FCS	20 ± 2.6	24 ± 1.0
NFCS or 1% FCS	6 ± 0.2	15 ± 0.8
Coculture with Caco-2 cells	96 ± 4.2	91 ± 3.1
Coculture with HT-29 cells	94 ± 3.8	90 ± 3.2
Caco-2-CM	53 ± 1.7	74 ± 1.3
HT-29-CM	60 ± 0.8	70 ± 1.3
TGF-β	90 ± 0.6	100 ± 0.8
PDGF	1 ± 0.1	1 ± 0.1
bEGF	5 ± 0.5	15 ± 0.8
IGF-I	5 ± 0.4	15 ± 0.6
IGF-II	5 ± 0.3	15 ± 0.5

FCS, fetal calf serum; NFCS, no fetal calf serum; S-CM, stromal cell-conditioned media; Caco-2-CM, Caco-2 cell-conditioned media; HT-29-CM, HT-29-conditioned media; TGF, transforming growth factor; PDGF, platelet-derived growth factor; bEGF, basic epidermal growth factor; IGF, insulin-like growth factor. Each experimental condition was assayed in triplicate, and three independent experiments were performed and the mean values are shown above.