Up-Regulation of miR-204 Enhances Anoikis Sensitivity in Epithelial Ovarian Cancer Cell Line Via Brain-Derived Neurotrophic Factor Pathway In Vitro.

OBJECTIVE

Genomic loci encoding miR-204, which was predicted to target brain-derived neurotrophic factor (BDNF), were frequently lost in multiple cancer, including epithelial ovarian cancer (EOC). In this study, we aimed to find out the influence of miR-204 expression level on EOC cell anoikis sensitivity and to explore possible mechanisms of this process.

METHODS

First, we screened EOC cells, which maintain anoikis resistance forming an anoikis pattern. miR-204 expression level and apoptosis were measured, respectively, by quantitative reverse transcriptase polymerase chain reaction and Annexin-V-R-PE/7-amino-actinomycin assay. Then we restored the expression level of miR-204 by transfection with pre-miR-204. miR-204 expression level and apoptosis were measured as before; cell invasion and migration ability were detected by transwell invasion assay and wound-healing assay. The messenger RNA level of BDNF was also detected by quantitative reverse transcriptase polymerase chain reaction; Western blot analysis was performed to assess pAKT expression.

RESULTS

Expression of miR-204 is significantly down-regulated in an anoikis pattern. Restored expression level of miR-204 enables cells to acquire more sensitivity to anoikis and decrease invasive and metastatic behavior, and also results in BDNF down-expression and inhibits activation of mitochondria-dependent pathway through the PI3K/AKT signaling pathway leading to cancer cell anoikis in EOC cells.

CONCLUSIONS

miR-204 up-regulation may be linked directly to the sensitivity of EOC cell anoikis by contributing to BDNF down-regulation. Our findings provide a novel mechanism for manipulating miR-204 levels therapeutically to restore anoikis sensitivity.