Down-Regulated miRNA-214 Induces a Cell Cycle G1 Arrest in Gastric Cancer Cells by Up-Regulating the PTEN Protein

To detect the expression of miRNA-214 in human gastric cancer cell lines of BGC823, MKN45 and SGC7901, and to identify the effect of miRNA-214 on cell cycle and apoptosis of these cells. Expression of miRNA-214 in human normal gastric mucosal cell line GES-1 and human gastric cancer cell lines was detected by real-time reverse-transcription polymerase chain reaction. Antisense-miRNA-214 oligonucleotides were transfected transiently into gastric cancer cell lines to down-regulate the expression of miRNA-214. The cell cycle and apoptosis were studied by flow cytometry assay. PTEN, one of the target genes of miRNA-214 was detected by using of immunocytochemistry and Western blotting. MiRNA-214 was overexpressed in gastric cancer cell lines of BGC823, MKN45 and SGC7901 compared with normal gastric mucosal cell line GES-1. Antisense-miRNA-214 oligonucleotides significantly down-regulated the expression of miRNA-214, and increased the portion of G1-phase and decreased the portion of S-phase in BGC823 and MKN45 cells. The immunocytochemistry test and Western blotting analysis showed that the down-regulation of miRNA-214 could significantly up-regulate the expression of PTEN in BGC823 and MKN45 cells. MiRNA-214 is overexpressed in human gastric cancer cell lines of BGC823, MKN45 and SGC7901. The down-regulation of miRNA-214 could induce a G1 cell cycle arrest in them, the up-regulation of PTEN maybe one of the mechanism.