Figure 4

Activated Akt inhibits IGF-1 induced EMT in an isoform-independent manner. A. Vector control or IGF-1R-expressing MCF10A cells were either left untreated or treated with IGF-I (100 ng/mL) for 72 hours and then analyzed by Western immunoblot using indicated antibodies. Authentication of IGF-1R expression was evidenced by an elevated phosphorylation of IGF-1R after IGF-I treatment. B. IGF-1R-expressing MCF10A cells were infected with retrovirus expressing either vehicle control (V), or Akt1 (1), -2 (2), or -3 (3) and then subsequently treated with IGF-I for an additional 3 days, followed by RT-qPCR analysis for assessing EMT-associated transcripts. Statistical significance was denoted by * if the transcripts in Akt-expressing cells significantly (p < 0.05) differed from the ones in vector control cells (V). C. Knocking down endogenous Akt by transfecting IGF-1R cells with siRNAs targeting either Akt1 or Akt2 or in combination were evidenced by a prominent loss of Akt expression assessed by Western blots. D. In IGF-1R-exprssing MCF-10A cells pre-treated with IGF-1, knocking down Akt rescue altered EMT-associated transcripts influenced by IGF-1R signaling (as compared to panel B).