Analgesic effects of microRNA-129-5p against bone cancer pain through the EphB1/EphrinB2 signaling pathway in mice.

The study aims to investigate the analgesic effects of microRNA-129-5p (miR-129-5p) on bone cancer pain (BCP) by targeting Eph receptor B1 (EphB1) through the EphB1/EphrinB2 signaling pathway. BCP mice models were established, and C3H/HeJ female mice were classified into the normal, blank, negative control (NC), miR-129-5p mimics, miR-129-5p inhibitors, EphB1 knockout (KO), and miR-129-5p inhibitors + EphB1 KO groups. Quantitative reverse transcription polymerase chain reaction and Western blot analysis were used to evaluate the miR-129-5p expression, and messenger RNA (mRNA) and protein expressions of EphB1, p-EphB1, EphrinB2, and p-EphrinB2. EphB1 and EphrinB2 were highly activated in the tibias of BCP mice 7 days after the operation. EphB1 is a target gene of miR-129-5p. The mechanical withdrawal threshold increased in the miR-129-5p mimics, EphB1 KO and miR-129-5p inhibitors + EphB1 KO groups, but decreased in the miR-129-5p inhibitors group. Compared with the blank and the NC groups, the expression of miR-129-5p was significantly increased in the miR-129-5p mimics group, and the mRNA and protein expressions of EphrinB2, p-EphrinB2, EphB1, and p-EphB1 were significantly decreased, while in the miR-129-5p inhibitors group, the results were opposite (all P < 0.05); the mRNA and protein expressions of EphrinB2, p-EphrinB2, EphB1, and p-EphB1 were significantly decreased in the EphB1 KO group (all P < 0.05); the expression of miR-129-5p was significantly decreased in the miR-129-5p inhibitors + EphB1 KO group ( P < 0.05), while the mRNA and protein expressions of EphrinB2 and p-EphrinB2 were not significantly different ( P > 0.05). The results indicated that upregulated miR-129-5p alleviate BCP via downregulation of the EphB1/EphrinB2 signaling pathway.