FOXO3a phosphorylation, transcriptional activity and Akt phosphorylation are regulated by SPHK1 in glioma cells.

<p>(A) SPHK1 phosphorylates FOXO3a in glioma cells. (B) FOXO3a-dependent transcription activity is regulated by overexpression (left panel) or knockdown (right panel) of SPHK1. Error bars represent mean ± SD from three independent experiments with similar results. *, <i>p</i><0.05. The GFP expression was used to indicate the transfection efficiency. (C) WB analysis of nuclear FOXO3a protein in indicated cells. (D) SPHK1 knockdown-induced upregulation of Bim could be reversed by silencing of FOXO3a in indicated glioma cells. (E) The phosphorylation status of Akt at Thr³⁰⁸ and Ser⁴⁷³ were assessed by WB in SPHK1 overexpressed and knocked-down glioma cell lines.