Fig. 2.

Growth inhibition of NMuMG cells by TGF-β involves RhoA-p160^ROCK activity. (A) NMuMG cells expressing RBD or control cDNA constructs were treated with increasing concentrations of TGF-β and assayed for [³H]thymidine incorporation. (B) Thymidine incorporation studies were done in MK, MDCK, and NMuMG cells in the presence of varying concentrations of TGF-β or Y23637. (C) Cells treated as indicated were subjected to sequential counts during a 3-day period in triplicate (mean ± SD). (D) At 48 h after siRNA transfection into NMuMG cells, p160^ROCK expression was analyzed by Western blotting. Similarly treated cells were subjected to fluorescence-activated cell sorter analysis for TGF-β-responsiveness to cell-cycle arrest.