Cripto-1 induces phosphatidylinositol 3′-kinase-dependent phosphorylation of AKT and glycogen synthase kinase 3β in human cervical carcinoma cells

AD Ebert, C Wechselberger, S Frank, B Wallace-Jones… - Cancer Research, 1999 - AACR
AD Ebert, C Wechselberger, S Frank, B Wallace-Jones, M Seno, I Martinez-Lacaci, C Bianco…
Cancer Research, 1999AACR
Abstract Cripto-1 (CR-1), a member of the epidermal growth factor-CFC peptide family,
activates the ras/raf/mitogen-activated protein/extracellular signal-regulated kinase/mitogen-
activated protein kinase pathway. In the present study, the role of CR-1 in the
phosphatidylinositol 3′-kinase (PI3K)/AKT (protein kinase B)/glycogen synthase kinase 3β
(GSK-3β)-dependent signaling pathway was evaluated in human SiHa cervical carcinoma
cells. Our data demonstrate that CR-1 can enhance the tyrosine phosphorylation of the p85 …
Abstract
Cripto-1 (CR-1), a member of the epidermal growth factor-CFC peptide family, activates the ras/raf/mitogen-activated protein/extracellular signal-regulated kinase/mitogen-activated protein kinase pathway. In the present study, the role of CR-1 in the phosphatidylinositol 3′-kinase (PI3K)/AKT (protein kinase B)/glycogen synthase kinase 3β (GSK-3β)-dependent signaling pathway was evaluated in human SiHa cervical carcinoma cells. Our data demonstrate that CR-1 can enhance the tyrosine phosphorylation of the p85 regulatory subunit of PI3K and transiently induce the phosphorylation of AKT in a time- and dose-dependent manner. In addition, CR-1 was found to induce the phosphorylation of GSK-3β. Phosphorylation of AKT and GSK-3β by CR-1 can be blocked by LY294002, a specific inhibitor of PI3K, thus leading to apoptosis. Finally, the apoptotic effect of LY294002 can be partially rescued by exogenous CR-1. In summary, our data suggest that human CR-1 may function as a survival factor through a PI3K-dependent signaling pathway involving AKT and GSK-3β.
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