Silencing of LncRNA-ANCR Promotes the Osteogenesis of Osteoblast Cells in Postmenopausal Osteoporosis via Targeting EZH2 and RUNX2.

PURPOSE

This study aimed to explore the effects and mechanisms of long non-coding RNA (lncRNA) anti-differentiation non-coding RNA (ANCR) on the osteogenesis of osteoblast cells in postmenopausal osteoporosis (PMOP).

MATERIALS AND METHODS

Mice models of PMOP were established. ANCR expression and intracellular calcium ions were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and laser confocal microscopy, respectively. ANCR was silenced in osteoblast cells from PMOP mice by the transfection of siRNA-ANCR (si-ANCR). The proliferation and apoptosis of osteoblast cells was analyzed by MTT and flow cytometry, respectively. Alkaline phosphatase (ALP) activity and calcium nodules were examined by ALP and alizarin red staining assay, respectively. The expression of enhancer of zeste homolog 2 (EZH2), runt related transcription factor 2 (RUNX2), and OSTERIX was detected by qRT-PCR and Western blot. Furthermore, an osteogenesis model was constructed in mice, and osteoid formation was observed by hematoxylin-eosin (HE) staining. The interaction between lncRNA-ANCR and EZH2 was further identified by RNA pull-down assay.

RESULTS

ANCR expression and intracellular calcium ions were increased in PMOP mice. Si-ANCR significantly increased the proliferation, ALP activity, calcium deposition of osteoblast cells and decreased apoptosis. ANCR and EZH2 were down-regulated by si-ANCR, while RUNX2 and OSTERIX were upregulated. Si-ANCR also promoted osteoid formation in mice treated with hydroxyapatite-tricalcium phosphate. In addition, ANCR specifically bound to EZH2.

CONCLUSION

Silencing ANCR promotes the osteogenesis of PMOP osteoblast cells. The specific binding of ANCR with EZH2 suppressed RUNX2, thereby inhibiting osteogenesis.