目的： 检测生长阻滞和DNA损伤诱导蛋白45g（growth arrest and DNA damage inducible protein 45g，GADD45g）基因在 急性髓系白血病（acute myeloid leukemia, AML）患者骨髓标本和细胞系中的表达情况及其表达水平与AML患者预后的关系，探 究过表达GADD45g对AML细胞增殖、凋亡、衰老、周期、分化和药物敏感性的影响。 方法： 选取中国医学科学院血液病医院 2013年1月至2016年12月初次诊断为AML患者的骨髓标本共27例，用Real-time PCR和Western blotting检测AML患者、正常对 照骨髓单个核细胞以及 AML 细胞系中 GADD45g mRNA 和蛋白水平的表达情况。在两个相互独立的数据集 GSE10358 和 GSE425-GPL317中分析GADD45g表达与AML患者的总生存率（overall survival，OS）和无事件生存率（event-free survival，EFS） 的相关性。构建GADD45g过表达慢病毒并感染AML细胞系U937、THP-1和Molm-13，通过生长曲线、集落形成、β-半乳糖苷酶 染色、流式细胞术分析Annexin V/7AAD染色和PI染色等方法分析GADD45g过表达对AML细胞增殖、克隆形成、衰老、凋亡、周 期、分化和化疗药物敏感性的影响。 结果： GADD45g在AML患者和AML细胞系中的表达水平显著低于正常对照（均P< 0.01）。低表达 GADD45g 的 AML 患者的 OS（P<0.05）和 EFS 较高表达患者显著缩短（均 P<0.05）。在 AML 细胞系中过表达 GADD45g能显著抑制细胞增殖、集落形成，显著促进细胞的凋亡、衰老、周期阻滞和分化，增强了细胞对化疗药物敏感性（P<0.05 或P<0.01）。 结论： GADD45g基因在AML患者骨髓组织和AML细胞系中低表达，对AML细胞系有显著的全方位的抑制作用， 其表达水平对AML具有预后判断价值。

Objective: To quantify the expression of growth arrest and DNA damage inducible protein 45g (GADD45g) gene in the bone marrow samples of patients with AML (acute myeloid leukemia) and in AML cell lines, as well as to study the correlation between the GADD45g expression and prognostic outcome in patients with AML and investigate the role of GADD45g over-expression in prolif- eration, apoptosis, senescence, differentiation, cell cycle arrest, and drug sensitivity in AML cell lines. Methods: In the study, a total of 27 cases of bone marrow specimens were selected from patients initially diagnosed as AML in Hospital of Blood Diseases affiliated to Chinese Academy of Medical Sciences from January 2013 to December 2016. mRNA and protein expression levels of GADD45g in BMMNCs (Bone marrow mononuclear cells) from patients with AML and healthy donors and in AML cell lines were quantified by quantitative real-time PCR and Western blotting. The correlation between GADD45g expression and overall survival (OS), coupled with event-free survival (EFS) in patients withAML was analyzed in two gene expression datasets (GSE10358, GSE425-GPL317). Len- tiviral vectors over-expressing GADD45g were constructed and transfected into AML cell lines (U937, THP-1 and Molm-13 cell lines). The role of GADD45g over-expression in cell proliferation, colony formation, senescence, apoptosis, cell cycle arrest, differentiation and drug sensitivity of U937, THP-1 and Molm-13 cells were detected by cell counting, colony-forming assay, β-galactosidase staining and flow cytometric analysis of Annexin V/7AAD staining, PI staining and so on, respectively. Results: Expression of GADD45g was dramatically down-regulated in BMMNCs in AML patients and AML cell lines compared to that from healthy donors (all P<0.01). The OS (P<0.05) and EFS (P<0.05) of AML patients with low GADD45g expression were significantly shorter that those of AML patients with higher GADD45g level. Enforced expression of GADD45g could inhibit cell growth and colony formation, promote senescence and apoptosis, induce cell cycle arrest and differentiation and enhance drug sensitivity in AML cell lines (P<0.05 or P<0.01). Conclu- sion: GADD45g expression was remarkably silenced in marrow tissues of patients with AML and AML cell lines; it showed remarkable and all-around inhibiting effect onAML cell lines, indicating that GADD45g expression has prognostic value inAML.

国家自然科学基金资助项目（No. 81670158, No.81470278，No.81600138，No.81700106）；天津市应用基础与前沿技术研究计划资助 项目（No. 17JCZDJC35100，No.15JCQNJC10300，No.17JCQNJC10800）