Fig. 6

PI3K/AKT pathway activity in melanoma cell lines. A Normalized expression (z-score) from genes (n = 49) corresponding to the MEK-dependent transcriptional signature [38] in MaMel cell lines. B Representative Western blot analysis of AKT and S6 phosphorylation in MaMel cell lines. The phosphorylated (p-) and total proteins are shown; GAPDH served as loading control. C Densitometric analysis of Western blots showing the relative intensity from p-AKT and p-S6 to total AKT and S6, respectively. Data from three independent experiments are shown (n = 3). D Heatmap displaying the scaled expression (z-score) of signature genes from MAPK/ERK, PI3K/AKT, and TGF-β pathways in 53 melanoma cell lines from Tsoi et al. [30], with different NRAS/BRAF mutation status and degrees of differentiation. The top annotations show the level of enrichment (ES) of the signatures in every cell line. E Enrichment of signatures from the MAPK/ERK, PI3K/AKT, and TGF-β pathways for the distinct differentiation subtypes within the aforementioned panel of melanoma cell lines