FIG. 11.

Thymidine incorporation in L6 cells following insulin, EGF, or serum exposure. L6hIR2 cells were transfected with the IRS-1 or the control ribozymes (IRS1-Rib or C-Rib, respectively) or pretreated with the MAPK or PKCβ inhibitors PD98059 and LY379196 (top). Alternatively, the cells were transfected with either the specific PKCα or PKCβ antisense oligonucleotide (ASPOα or ASPOβ, respectively) or the control oligonucleotides specified in the legend to Fig. 5 (POα and POβ). The cells were exposed to 100 nM insulin or to EGF or to 10% fetal calf serum (FCS) for 12 h, as indicated. [³H]thymidine incorporation into DNA was then assayed as described in Materials and Methods. Bars represent the means ± standard deviations of triplicate determinations in four independent experiments.