Fig. 6. The changes in expression of G1-S regulators in differentiating EC cells. Both A.1 and 1.3 EC cells were cultured for 48 h with and without 10-6 M RA and then extracted for protein analysis. Equal amounts of total protein of each cell line were separated on 10% SDS-PAGE and Western analyzed using the appropriate antibody. A, regulators visualized by chemiluminescence. B, densitometric analysis of p27 and cyclin D3 data shown in A. Arbitrary units are shown on the Y axis. Data are representative of at least three independent replicates.