Figure 1.

Smad4 C324Y stable clones proliferation in absence of TSH or insulin. (A and B) After starvation in 4H/0.5% BS medium for 24 h, FRTL-5 and stable clones (10×10⁴) were grown in F-12 Coon’s modification medium supplemented with 0.5% BS and 5H mixture, 6H mixture without (A) TSH or (B) insulin. Growth curves have been obtained counting the cells at time zero (T0), 24, 48, 72 and 96 h. Cells were counted three times by two independent investigators. Inter-observer variation was below 5%. Values represent mean of triplicate determination ± SD of three experiments [^* indicates a statistical significance (Student’s t-test, P<0.05) of Smad4 C324Y clones vs. control cells].