MicroRNA‑214 promotes proliferation and inhibits apoptosis via targeting Bax in nasopharyngeal carcinoma cells.

The deregulation of microRNAs (miRNAs) is involved in the development and progression of various types of human malignancy. Previously, it has been suggested that miR‑214 has an oncogenic role in nasopharyngeal carcinoma. However, the detailed molecular mechanisms remain to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction and western blot analysis were conducted to determine the relative mRNA and protein levels, respectively. The MTT assay was performed to examine cell proliferation. Flow cytometry was conducted to determine cell apoptosis level. In the present study, the expression of miR‑214 was found to be notably upregulated in nasopharyngeal carcinoma tissues and cell lines. Further investigation demonstrated that inhibition of miR‑214 inhibited proliferation and promoted apoptosis in nasopharyngeal carcinoma cells. By contrast, overexpression of miR‑214 promoted nasopharyngeal carcinoma cell proliferation and inhibited cell apoptosis. Bcl‑2‑associated X protein (Bax) was then identified as a novel target of miR‑214. miR‑214 negatively regulated the protein expression of Bax in nasopharyngeal carcinoma cells. siRNA‑induced Bax inhibition attenuated the promoting effect of miR‑214 downregulation on nasopharyngeal carcinoma cell apoptosis, suggesting that Bax acts as a downstream effector in miR‑214‑mediated nasopharyngeal carcinoma cell proliferation and apoptosis. Finally, the present study demonstrated that the expression level of Bax was downregulated in nasopharyngeal carcinoma tissues. In conclusion, the present study suggests that miR‑214 may be a potential target for the treatment of nasopharyngeal carcinoma.