Fig. 3.

TGFB1 reduces DNA synthesis in CLENDO cells. (A) [³H]-thymidine incorporation assay of cells plated at low density and treated with or without TGFB1 (0–10 ng/ml) in the absence (CTL, control) or presence of 5% FCS for 24 hours. (B) [³H]-thymidine incorporation assay of cells plated at low density and treated for 24 hours with or without TGFB1 (1 ng/ml) in the absence (CTL) or presence of 5% FCS. Some cells were pretreated (30 minutes) with the selective TGFBR1 receptor kinase inhibitor SB-431542 (SB, 1 μM) prior to addition of TGFB1. Data are expressed as the percent incorporation of [³H]-thymidine compared to the maximal response group. Data shown represent three independent experiments each performed in triplicate (mean + s.e.m., n=3, *P<0.05). (C) MTT assay of CLENDO cells plated on plastic at low density and treated for 24 hours with or without TGFB1 (1 ng/ml) in the absence (CTL) or presence of 5% FCS. Some cells were pretreated (30 minutes) with SB-431542 (1 μM) prior to addition of TGFB1. Results are expressed as the percent absorbance observed in the control group. Data shown represent three independent experiments each performed in triplicate (mean ± s.e.m., n=3).