罗格列酮对骨髓瘤细胞HIF1α和IGF1mRNA表达的影响及其可能机制

Effect of rosiglitazone on the expression of HIF1α and IGF1 mRNA in myeloma

目的 观察罗格列酮作用后骨髓瘤细胞HIF1α和IGF1 mRNA表达水平,探讨罗格列酮抑制骨髓瘤血管形成的可能机制.方法 以骨髓瘤细胞系RPMI 8226细胞及5例初诊多发性骨髓瘤患者骨髓浆细胞（CD138免疫磁珠筛选,作为骨髓瘤原代细胞）为研究对象,采用RT-PCR法检测用不同浓度（10、20、40 μmol/L）罗格列酮处理前后骨髓瘤细胞HIF1α、IGF1 mRNA表达水平;采用Westernblot法检测AKT和ERK蛋白磷酸化和非磷酸化表达的情况.同时以5例缺铁性贫血患者的骨髓单个核细胞为对照组.结果 RPMI8226细胞和骨髓瘤原代细胞HIF1α和IGF1 mRNA表达显著高于对照组.罗格列酮浓度为20 μmol/L处理48 h后,与对照组相比,RPMI 8226细胞中HIF1α、IGF1 mRNA相对表达水平分别由1.21±0.08和0.62±0.06降至0.75±0.06和0.32±0.04,骨髓瘤原代细胞中HIF1α、IGF1mRNA表达水平分别由2.02±0.16和1.92±0.13降至0.53±0.04和0.58±0.03,差异均有统计学意义（P值均＜0.05）,且呈剂量依赖性;10、20、40 μmol/L罗格列酮均可抑制RPMI8226细胞pAKT、pERK蛋白的表达,然而对骨髓瘤原代细胞T-AKT和T-ERK蛋白表达没有明显影响.结论 罗格列酮可抑制HIF1α、IGF1 mRNA的表达,降低pAKT和pERK蛋白的表达可能是其抑制肿瘤血管形成机制之一.

Objective To observe the effect of rosiglitazone （RGZ） on the mRNA expression of HIF1α and IGF1 genes in the myeloma cells and explore possible mechanism of angiogenesis inhibition.Methods Human myeloma cell line RPMI 8226 and primary myeloma cells from five patients enriched by using CD 138 immunomagnetic beads were treated with different concentrations （10,20,40 μmol/L）of RGZ.The mRNA expression of HIF1α and IGF1 was analyzed in cells treated with RGZ after 48h by RT-PCR,The levels of phosphorylated AKT and ERK proteins were detected by Western blotting.Bone marrow mononuclear cells from five patients with iron deficiency anemia were regarded as control.Results Higher mRNA expression of HIF1α and IGF1 genes in RPMI8226 and in primary myeloma cells was showed as compared to those in control.Treated with RGZ of 20 μmol/L after 48 h,the mRNA expression of HIF1α （1.21±0.08 vs 0.75±0.06） and IGF1 （0.62±0.06 vs 0.32±0.04） in RPMI8226 cells was declined as compared to those without RGC treatment.The same declination was also seen in in primary myeloma cells （HIF 1 α：2.02±0.16 vs 0.53±0.04; IGF 1：1.92±0.13 vs 0.58±0.03）.RGZ could inhibit the expression of pAKT and pERK,nor the total AKT and ERK proteins,in RPMI8226 cells in a dose-dependent manner at the concentration of 10 μmol/L,20 μmol/L,and 40 μmol/L.Conclusions RGZ could inhibit the mRNA expression of HIF 1 α and IGF 1.Inhibition of angiogenesis by RGZ may be associated with down-regulation of pAKT and pERK expression.