RESUMO
BACKGROUND; Previous studies have shown that various miRNAs play a role in bone formation. miR-335-5p can protect osteoblasts from oxidative stress and protect osteoblasts under induction with ferric ammonium citrate, but the effect of miR-335-5p on osteoblast proliferation and apoptosis in high glucose environments is unknown. OBJECTIVE: To investigate the effect of miR-455-3p targeting HIPK2 on proliferation and apoptosis of osteoblasts induced by high glucose. METHODS; Dual luciferase reporter assay was used to verify the targeting of miR-455-3p to HIPK2. MC3T3-E1 cells were induced by high glucose in vitro, and MC3T3-E1 cells were treated as follows: Blank group, high glucose group, high glucose+miR-control group, high glucose+miR-455-3p group, high sugar+si-control group, high sugar+si-HIPK2 group, high glucose+miR-455-3p+pcDNA group and high glucose+miR-455-3p+pcDNA-HIPK2 group. The expression of miR-455-3p and HIPK2 mRNA was detected by qRT-PCR, cell viability was detected by MTT assay, apoptosis was detected by flow cytometry, and the expression of HIPK2, p-STAT3 and STAT3 protein was detected by western blot. RESULTS AND CONCLUSION: HIPK2 was a target gene of miR-455-3p, and miR-455-3p negatively regulated the expression of HIPK2. High glucose treatment inhibited the expression of miR-455-3p and promoted the expression of HIPK2. The over-expression of miR-455-3p or the inhibition of HIPK2 promoted MC3T3-E1 survival and inhibit cell apoptosis after high glucose treatment. The over-expression of HIPK2 partially reversed the survival promotion and apoptosis inhibition of miR-455-3p on osteoblasts induced by high glucose. miR-455-3p inhibited the expression of p-STAT3 in osteoblasts by regulating HIPK2. To conclude, miR-455-3p inhibits the apoptosis and promotes the proliferation of osteoblasts induced by high glucose via down-regulating HIPK2, which may be related to the inhibition of STAT3 signaling pathway.
RESUMO
@#Objective: To investigate the potential effects of miR-455-3p on proliferation, invasion and epithelial-mesenchymal transition (EMT) process of ovarian cancer cells, and explore its molecular mechanism. Methods: The IOSE80, SKOV-3 and A2780 cells were transfected with miR-455-3p mimics and negative controls (NC) by using LipofectamineTM 2000. Quantitative polymerase chain reaction (qPCR) assay was performed to detect the mRNA expressions of miR-455-3p and fatty acid-binding protein 4 (FABP4) in IOSE80, SKOV-3 and A2780 cells. The expression levels of FABP4 and EMT-associated proteins were detected by Wb. CCK-8 assay was applied to measure cell proliferation. Cell migration was analyzed by using Transwell assay. Bioinformatics analysis was used to predict the potential target of miR-455-3p, and the targeting effect of miR-455-3p on FABP4 was verified by the dual-luciferase reporter assay system. Results: The expression of miR-455-3p was declined (all P<0.05), while the expression of FABP4 was elevated (all P< 0.05) in ovarian cancer cells (SKOV-3 and A2780) in comparison with normal ovarian IOSE80 cells. Additionally, over-expression of miR-455-3p obviously inhibited cell proliferation and migration capacity of SKOV-3 cells (all P<0.05). Furthermore, over-expression of miR-455-3p impeded EMT progress by up-regulating E-cadherin expression and down-regulating N-cadherin and vimentin expression (all P<0.05). Importantly, the dual-luciferase reporter system, qPCR and Wb validated that FABP4 was a specific target gene of miR-455-3p, and miR-455-3p showed specific binding with FABP4 3’-UTR and negatively regulated the expression of FABP4 at both mRNA and protein levels. Mechanistically, over-expression of FABP4 apparently reversed the inhibitory effects of miR-455-3p on cell proliferation and migration of SKOV-3 cells (all P<0.05). Conclusion: miR-455-3p, acting as a tumor suppressor protein, can inhibit ovarian cancer cell proliferation, migration and EMT process by targeting FABP4, suggesting that miR-455-3p may be a new potential therapeutic target for ovarian cancer treatment.