Upregulation of forkhead box O3 transcription is involved in C2-ceramide induced apoptosis and autophagy in ovarian cancer cells in vitro.

Abstract

Ceramide is a bioactive lipid which functions as a tumor suppressor, mediating processes such as apoptosis, growth arrest, senescence and differentiation. The effects of ceramide in ovarian cancers have not been well established. The objective of the present study was to investigate the effects of C2‑ceramide treatment in A2780 ovarian cancer cells and its possible molecular mechanism. C2‑ceramide-induced proliferation inhibition was analyzed using an MTT assay and Trypan blue test. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling were used to identify the induction of apoptosis. Transmission electron microscopy was used to confirm the formation of autophagosomes. Quantitative polymerase chain reaction was performed to analyze the messenger RNA expression of the autophagy and cell death associated genes and western blotting was used to analyze the protein expression of beclin 1, LC3, Akt, forkhead box O3 (FOXO3) and adenosine monophosphate-activated protein kinase in ovarian cancer cells. It was found that C2‑ceramide inhibited A2780 cell proliferation in a time‑ and dose‑dependent manner and C2‑ceremide induced A2780 cell apoptosis and autophagy. However, C2‑ceramide‑induced autophagy did not result in cell death, but instead protected ovarian cancer cells from apoptosis. Akt inhibition and FOXO3 activation were implicated in C2‑ceramide‑treated ovarian cancer cells. Furthermore, FOXO3 target genes, which were associated with autophagy (MAP1LC3, GABARAP and GABARAPL1) and cell death (BNIP3, BNIP3L, BIM and PUMA), were upregulated. The present study has shown that C2‑ceramide induced apoptosis and autophagy in ovarian cancer cells. FOXO3 transcription was upregulated, which may contribute to C2‑ceramide‑induced apoptosis and autophagy.