FIG. 5.

TSH exerts differential effects on Ras^S35 and Ras^G37-mediated proliferation. Ni, cell number at day N; No, number of cells plated on day 1. (A) Cells were plated in 3H medium overnight and transferred to 2H medium, and cell number was assessed at days 2 and 4 (open symbols). On day 4, replicate plates were fed 3H (filled symbols) or 2H (open symbols) medium, and the cell number was determined 2 days later. Results shown are the means ± standard deviations from three experiments performed in duplicate with similar results. The absence of an error bar indicates a standard deviation of 1 or less. Two independent isolates of Ras^G37-expressing cells were analyzed with similar results. (B) Experimental conditions were the same as for panel A with Ras^S35 cells. Three experiments with three independent Ras^S35 isolates were performed in duplicate with similar results. (C) Ras^G37 cells were incubated in 2H medium (−TSH) or 3H medium (+TSH), and BrdU incorporation was measured over 24 h. WRT cells were included for comparison. Error bars indicate 95% confidence intervals. Three experiments performed in duplicate gave similar results. (D) BrdU incorporation in Ras^S35 cells with or without TSH. Cells were incubated in basal medium for 48 h and subsequently stimulated with the same medium (−TSH) or TSH-supplemented medium (+TSH) containing BrdU for 24 h. Error bars indicate 95% confidence intervals. Four experiments yielded similar results.