Prognostic significance of myeloperoxidase expression in childhood acute myeloid leukemia

Proteomic Studies of Primary Acute Myeloid Leukemia Cells Derived from Patients Before and during Disease-Stabilizing Treatment Based on All-Trans Retinoic Acid and Valproic Acid

All-trans retinoic acid (ATRA) and valproic acid (VP) have been tried in the treatment of non-promyelocytic variants of acute myeloid leukemia (AML). Non-randomized studies suggest that the two drugs can stabilize AML and improve normal peripheral blood cell counts. In this context, we used a proteomic/phosphoproteomic strategy to investigate the in vivo effects of ATRA/VP on human AML cells. Before starting the combined treatment, AML responders showed increased levels of several proteins, especially those involved in neutrophil degranulation/differentiation, M phase regulation and the interconversion of nucleotide di- and triphosphates (i.e., DNA synthesis and binding). Several among the differentially regulated phosphorylation sites reflected differences in the regulation of RNA metabolism and apoptotic events at the same time point. These effects were mainly caused by increased cyclin dependent kinase 1 and 2 (CDK1/2), LIM domain kinase 1 and 2 (LIMK1/2), mitogen-activated protein kinase 7 (MAPK7) and protein kinase C delta (PRKCD) activity in responder cells. An extensive effect of in vivo treatment with ATRA/VP was the altered level and phosphorylation of proteins involved in the regulation of transcription/translation/RNA metabolism, especially in non-responders, but the regulation of cell metabolism, immune system and cytoskeletal functions were also affected. Our analysis of serial samples during the first week of treatment suggest that proteomic and phosphoproteomic profiling can be used for the early identification of responders to ATRA/VP-based treatment.

[Correlation between myeloperoxidase expression and gene alterations and prognosis in acute myeloid leukemia]

目的

观察髓过氧化物酶（MPO）在急性髓系白血病（AML）中的表达，探讨其与AML临床特征、基因突变、疗效和预后的关系。

方法

回顾性分析233例初诊AML患者骨髓中原始细胞MPO表达的阳性率，根据MPO表达率不同将其分为MPO低表达组（MPO≤70%）与MPO高表达组（MPO>70%），并对两组患者的临床特征、基因突变、疗效和预后进行比较。

结果

①233例AML患者中MPO低表达组121例（51.9%），MPO高表达组112例（48.1%）。NCCN预后良好组患者多为MPO高表达（χ²=32.773，P<0.001），而MPO低表达与预后不良核型相关（χ²=7.078，P=0.008）。②MPO低表达组DNMT3A基因（χ²=6.905，P=0.009）、RNA剪接复合物相关基因（SF3B1/SRSF2/U2AF1）（χ²=5.246，P=0.022）、RUNX1基因（χ²=4.577，P=0.032）、ASXL1基因（χ²=7.951，P=0.005）及TP53基因(P=0.004）突变发生率明显高于MPO高表达组，而C-KIT基因（χ²=8.936，P=0.003）及CEBPA基因（χ²=12.340，P<0.001）突变更多见于MPO高表达组，尤其CEBPA双位点突变。③MPO低表达组首次诱导治疗缓解（CR₁）率为38.8%，MPO高表达组为68.1%，差异有统计学意义（χ²=15.197，P<0.001）。多因素分析显示MPO低表达是影响患者CR₁的独立危险因素。④MPO低表达组患者的2年总生存（OS）率及无进展生存（PFS）率均明显低于高表达组（18.0%对89.4%和11.5%对56.7%），差异有统计学意义（χ²分别为15.212和17.016，P值均<0.001）。Cox模型多因素分析显示MPO低表达是影响患者OS及PFS的独立预后不良指标。⑤正常核型AML中，MPO低表达组患者OS和PFS差于MPO高表达组（2年OS率：31.1%对83.7%，χ²=2.895，P=0.089；2年PFS率：18.8%对45.8%，χ²=5.068，P=0.024）。

结论

不同MPO表达的AML具有独特的基因突变谱；MPO低表达是影响AML患者CR₁、OS和PFS的独立危险因素，细胞化学染色检测MPO表达可能为评估AML疗效和预后提供一种简单而有效的手段。