Rheb在人急性髓系白血病中的作用研究

Role of Rheb in Human Acute Myeloid Leukemia

目的:通过检测Rheb在成人急性髓系白血病患者(AML)骨髓细胞中的表达,探讨Rheb在AML发生发展中的作用。方法:选择27例AML患者和29例特发性血小板减少性紫癜(ITP)初诊患者的骨髓单个核细胞(BMMNC),用实时定量PCR(RT-PCR)方法检测Rheb的表达水平;分析Rheb表达水平与AML患者年龄、分型、融合基因、脾脏肿大、肝脏肿大相关性。比较Rheb高表达组与Rheb低表达组患者生存时间的差异。构建过表达Rheb的HL-60细胞,应用不同浓度阿糖胞苷处理HL-60细胞和过表达Rheb的HL-60细胞,用CCK-8法检测细胞增殖情况并计算IC_(50)。结果:Rheb在AML患者骨髓单核细胞中表达与ITP患者骨髓单核细胞的表达相比较没有明显差异。Rheb高表达患者相对预后较好,对阿糖胞苷治疗敏感。Rheb表达量与患者年龄、分型、融合基因和肝肿大不相关,与脾脏肿大相关(P<0.05)。体外实验表明,在AML细胞系HL-60中过表达Rheb,可以提高细胞对阿糖胞苷敏感性(IC50=0.54μmol/L)。结论:Rheb低表达可以预示不良预后,且与AML患者脾脏肿大相关,对阿糖胞苷治疗不敏感。

Objective: To investigate the role of Rheb( m TOR activator) in AM L development by measuring Rheb expression in bone marrow of adult AM L patients and in AM L cell line HL-60. Methods: Real-time PCR assay w as used to measure the Rheb mRNA expression in 27 AM L patients and 29 ITP patients as control. The relationship betw een Rheb mRNA expression and age,AM L subtype,fusion gene,splenomegaly,hepatomegaly and survival of AM L patients w as analyzed and compared. In addition,HL-60 cell line over-expressing Rheb w as established,and the HL-60 cells and HL-60 cells w ith overexpression of Rheb w ere treated w ith Ara-C of different concentrations,the proliferation level w as detected by CCK-8 method,and the IC50 w as calculated. Results: The mRNA level of Rheb in AM L patients w as similar to that in ITP patients( control). Interestingly,higher expression of Rheb w as associated w ith better survival and w as sensitive to Ara-C treatment. How ever,the expression level of Rheb w as not associated w ith age,AM L subtype,fusion gene,and hepatomegaly of patients. Low er expression level of Rheb w as associated w ith splenomegaly.In vitro analysis of HL-60 line indicated that overexpression of Rheb could increased the cell sensitivity to Ara-C treatment( IC50= 0. 54 μmol / L) and caused HL-60 cell apoptosis. Conclusion: The low er Rheb expression is a poor prognostic indicator for AM L patients,w hich is associated w ith AM L splenomegaly,the patients and HL-60 cells w ith low expression of Rheb are insensitive to Ara-C treatment.