Formononetin inhibits osteosarcoma cell proliferation and promotes apoptosis by regulating the miR-214-3p/phosphatase and tensin homolog pathway.

Background: Phytoestrogens have a similar molecular structure to estrogens which can produce either estrogenic or anti-estrogenic effects. It is generally believed that phytoestrogens combine with the estrogen receptor of osteosarcoma cells, affecting a variety of signal transduction pathways and cell metabolism, resulting in altered cell proliferation, differentiation, apoptosis, invasion and migration ability. Formononetin (FN) is the active ingredient of traditional Chinese medicine astragalus, angelica, and Pueraria lobate. Our study aims to detect the role of FN on MG-63 cell viability and apoptosis through regulating phosphatase and tensin homolog (PTEN) expression via MicroRNA-214-3p (miR-214-3p).

Methods: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Caspase 3 assay evaluated cell viability and apoptosis, respectively. Real-time quantitative polymerase chain reaction (qRT-PCR) and western blot evaluated the mRNA and protein expressions, respectively. The binding site of miR-214-3p/PTEN was detected via dual luciferase assay.

Results: FN suppressed cell viability and induced apoptosis, and decreased miR-214-3p level and promoted PTEN expression. PTEN was then regarded as a target of miR-214-3p, and FN improved PTEN level via inhibiting miR-214-3p. Further analysis showed that overexpressed miR-214-3p improved cell viability and suppressed apoptosis of MG-63 cells by inhibiting PTEN expression.

Conclusions: Finally, our results revealed that FN inhibited cell viability and induced apoptosis by regulating miR-214-3p. FN acted as a new treatment for MG-63 cells via increasing PTEN level by inhibiting the miR-214-3p level.