FIGURE 6.

c-Jun-dependent PDK1 regulation contributes to melanoma growth and tumorigenesis. A, c-Jun-dependent PDK1 expression regulates in vitro cell growth. Cells (10⁴) described in the legend for Fig. 4C were plated and the cell number determined on the indicated days. Results are shown as mean ± S.D. (n = 3). ** represents p < 0.0001. * represents p < 0.001. B, c-Jun-dependent PDK1 expression regulates tumor growth in vivo. Cells described in the legend for Fig. 4C were injected subcutaneously into mice and tumor volume was measured at the indicated times. Results are shown as mean ± S.D. (n = 5). * represents p < 0.0005. Protein extracts (40 μg) obtained from tumors removed from mice were analyzed by Western blots using the indicated antibodies. #1 and #2 indicate samples from different mice. C and D, lentiviral c-Jun-specific shRNA efficiently knockdowns c-Jun expression and reduces PDK1 expression. Protein extracts (30 μg) from cells transduced with c-Jun-specific shRNA were analyzed by Western blotting using the indicated antibodies. E and F, PDK1 expression reverts the defect in tumor growth of c-Jun knockdown cells. Cells described in D were injected subcutaneously into mice. Tumor growth was measured as described in B. Results are shown as mean ± S.D. (n = 4). * represents p < 0.0001. F, protein extracts (40 μg) obtained from tumors removed from mice were analyzed by Western blots using the indicated antibodies. #1 and #2 indicate samples from different mice.