Expression And Methylation Regulation Of Insulin Like Growth Factor Binding Protein 7 In Multiple Myeloma

Objective:Multiple Myeloma(MM)is still an incurable malignant plasma cell tumor.To investigate the expression of insulin-like growth factor binding protein 7(IGF-BP7)gene in multiple myeloma cell line U266,and research the effect of 5-aza-2?-deoxycytidine(5-aza-dc)on cell proliferation of U266.Methods:Multiple myeloma cell line U266 was cultured in vitro.The bone marrow mononuclear cells from normal control persons(N-BMMNC)were collected and used as normal controls.The IGFBP7 mRNA expression of U266 and N-BMMNC were detected by real-time fluorescence quantitative PCR,DNA methylation status of the CpG island of IGFBP7 was measured using methylation-specific PCR(MSP),Different concentrations of 5-aza-dc(5?mol/L,10?mol/L,20 ?mol/L)treated U266 48 hours,RT-PCR and Western blot were used to detect the effect of IGFBP7 mRNA and protein expressions,cell growth curve and Annexin V/PI were analyzed by FCM.Statistical analysis: all datas are available on SPSS17.0 statistical package processing.measurement datas used x±SD for statistical description,Comparision between the two groups was the t methods,Multiple sets of datas used the single-factor analysis of variance.All results will have statistical significance which based on P<0.05.Results:Compared with N-BMMNC the lower expression of IGFBP7 gene was found in U266 cells,the hypermethylation of the CpG island in the IGFBP7 promoter was observed.U266 treating with different concentrations of 5-aza-dc,the IGFBP7 mRNA and protein expression was up-regulated dose-dependently(P<0.05),U266 cells grew slowly and apoptosis rates up-regulated dose-dependently.Conclusion:The lower expression of IGFBP7 gene was found in U266 cells compared with N-BMMNC,The mechanism connect with the hypermethylation of the Cp G island in the IGFBP7 promoter.5-aza-dc can up-regulate IGFBP7 mRNA and protein expression.U266 cells grew slowly and up-regulate apoptosis rates inducing cell proliferation significantly decreased.