Downregulation of YAP inhibits proliferation and induces apoptosis in Eca-109 cells.

A previous study reported that Yes-associated protein (YAP) gene was overexpressed in esophageal squamous cell carcinoma (ESCC); however, the exact role of YAP in ESCC remains largely unclear. The present study aimed to investigate the effects of YAP inhibition on ESCC. In order to investigate the exact role of YAP in ESCC cells, a stable YAP low-expression ESCC cell line was established using YAP-small interfering RNA. MTT assay was performed to examine the cell proliferation ability, while flow cytometry were used to detect the cell apoptosis and cell cycle distribution. In addition, reverse transcription-quantitative polymerase chain reaction and western blot analysis were applied for mRNA and protein level detection, respectively. The results suggested that YAP gene inhibition significantly repressed the ECA-109 cell proliferation and induced cell apoptosis, whereas this inhibition had no significant effects on cell cycle. Furthermore, the expression levels of cell apoptosis-associated proteins were determined in the current study, and the data demonstrated that the B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein ratio and phosphorylated extracellular signal-regulated kinase expression were significantly reduced, while the p53 and caspase 3 levels were notably increased in YAP gene-inhibited ECA-109 cells. In conclusion, the current study revealed that YAP gene inhibition suppresses the proliferation and induces apoptosis in ECA-109 cells, indicating that the YAP gene serves as an oncogene in ESCC.