LncRNA NONRATT021203.2通过调控miRNA-138-5p表达促进骨癌痛进展OA

Objective:To investigate the role of the long non-coding RNA(lncRNA)NONRATT021203.2 in the progression of cancer-induced bone pain(CIBP)and its potential molecular mechanisms.Methods:A CIBP model was constructed in Sprague-Dawley(SD)rats by intratibial inoculation of Walker 256 breast cancer cells.Sixteen adult female SD mice weighing 180-200 g were randomly divided into control group and CIBP group,with 8 rats in each group,and injected into tibiae with 10 μL normal saline and 10 μL Walker 256 breast cancer cell suspension(1 × 108 cells/mL),respectively.Paw withdrawal threshold(PWT)and paw withdrawal latency(PWL)of the modeled lower limb of rats were detected by behavioral analysis.The expression levels of lncRNA NONRATT021203.2 and miRNA-138-5p in DRG were measured by using quantitative real-time PCR(qRT-PCR),and the localization of miRNA-138-5p in DRG tissue was examined by fluorescence in situ hybridization(FISH).Seven days after modeling,10 rats with CIBP were selected and divided into CIBP+siRNA group(n=5)and CIBP+siNC group(n=5),lncRNA NONRATT021203.2-siRNA and siNC were injected intrathecally,respectively.The relative expression levels of lncRNA NONRATT021203.2 and miRNA-138-5p in the two groups were detected by qRT-PCR.Additionally,seven days after modeling,16 rats with CIBP were divided into CIBP+mimics(n=8)and CIBP+NC group(n=8),miRNA-138-5p mimics and negative control oligonucleotide were injected intrathecally,respectively.PWT and PWL were detected by behavioral test.Finally,the binding sites of lncRNA NONRATT021203.2 and miRNA-138-5p were analysed by using miRand and miRwalk3.0 software.Results:Compared with control group,CIBP group showed significantly reduced PWT and PWL(P＜0.05),markedly increased expression of lncRNA NONRATT021203.2(P＜0.01),and significantly decreased expression of miRNA-138-5p(P＜0.001).FISH results showed that miRNA-138-5p was localized in neuronal cytoplasm.Compared with CIBP+siNC group,CIBP+siRNA group exhibited significantly reduced lncRNA NONRATT021203.2 expression(P＜0.05)and increased miRNA-138-5p expression(P＜0.05).Compared with CIBP+NC group,PWT was significantly increased in CIBP+miRNA-138-5p mimics group(P＜0.01).Bioinformatics analysis revealed the presence of a potential binding site between lncRNA NONRATT021203.2 and miRNA-138-5p.Conclusion:LncRNA NONRATT021203.2 could reduce the intracellular free miRNA-138-5p level by competitively binding to miRNA-138-5p,thereby promoting the occurrence and development of bone cancer pain.