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Fig. 6. Induction of lumen formation by RAR-pan-reactive and RAR
-selective
synthetic retinoids. (A) J3B1A cells were suspended in collagen gels and
incubated either with 0.1% DMSO (control) or with a wide range of
concentrations of the RAR-selective agonist TTNPB. (B) J3B1A cells were
suspended in collagen gels and incubated either with 0.1% DMSO (control) or
with different concentrations of Am-580, a selective RAR
ligand. Lumen
formation was quantified after 6 days as described in Materials and Methods.
Results are expressed as mean percentage of cysts±s.e.m. in 20 randomly
selected photographic fields (five fields from each of four separate
experiments) per experimental condition. In A, 1=P<0.05;
2=P<0.025; 3=P<0.0005 (compared with control values);
in B, *=P<0.0005 (compared with control values).