Kao Hsiao-Wen, Kuo Ming-Chung, Ou Che-Wei, Huang Ting-Yu, Chang Hung, Lin Tung-Liang, Hung Yu-Shin, Wu Jin-Hou, Shih Lee-Yung
Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
College of Medicine, Chang Gung University, Taoyuan, Taiwan.
J Pathol. 2025 Apr;265(4):437-447. doi: 10.1002/path.6396. Epub 2025 Feb 5.
This study investigated the clonal evolution of chronic myelomonocytic leukemia (CMML) progression to secondary acute myeloid leukemia (sAML) by next-generation sequencing and pyrosequencing for variant allele frequency (VAF) of gene mutations and SNP microarray for copy neutral loss of heterozygosity (CN-LOH) in 38 paired samples from CMML/sAML patients of Taiwanese origin. The median interval between CMML and sAML samples collection was 14.9 months (1.0-89.6). RUNX1 (57%), TET2 (46%), SRSF2 (37%), and ASXL1 (28%) mutations were frequent at CMML diagnosis. Baseline VAF in epigenetic regulator genes was high (>35%) in 83% of mutational events at the CMML phase, remained stable in 78% (VAF changes <10%), and increased in 20% (increased VAF > 10%) during progression to sAML. Transcription factor genes showed high VAF (>35%) in 51% at the CMML phase, and stable VAF in 60% during progression. VAF of spliceosome genes was high (>35%) in 70% at CMML phase, and stable in 61% during progression. Activated signaling genes exhibited acquisition or loss during progression. TET2 mutations were often founding clones, and SRSF2, ASXL1, DNMT3A, EZH2, or spliceosome genes also acted as ancestral mutations. RUNX1 mutations were typically later events and occasionally ancestral hits or germline mutations. Acquisition of cytogenetic changes, signaling pathways genes (PTPN11, FLT3, NRAS, CBL), or AML-defined genes (NPM1, CEBPA, CBFB::MYH11) by linear or branching evolution occurred during sAML progression. CN-LOH was noted in EZH2, CBL, TET2, and DNMT3A genes. CEBPA mutation and concurrent biallelic TET2 with NRAS mutations at CMML diagnosis were risk factors for time to AML progression and overall survival. A characteristic ASXL1/RUNX1/Spliceosome/signaling genetic profile was associated with monocyte counts of 0.5-1.0 × 10/l. This study highlights the complexity and heterogeneity of dynamic changes in clonal architecture during CMML progression, emphasizing its importance in pathogenesis, phenotype, risk stratification, and therapeutic strategy. © 2025 The Pathological Society of Great Britain and Ireland.
本研究通过下一代测序和焦磷酸测序检测基因突变的变异等位基因频率（VAF），并利用单核苷酸多态性微阵列检测杂合性拷贝中性缺失（CN-LOH），对38例源自台湾的慢性粒单核细胞白血病（CMML）进展为继发性急性髓系白血病（sAML）的配对样本进行研究。CMML和sAML样本采集的中位间隔时间为14.9个月（1.0 - 89.6个月）。CMML诊断时，RUNX1（57%）、TET2（46%）、SRSF2（37%）和ASXL1（28%）突变较为常见。在CMML阶段，83%的突变事件中表观遗传调节基因的基线VAF较高（>35%），在进展为sAML期间，78%的VAF保持稳定（VAF变化<10%），20%的VAF升高（VAF升高>10%）。转录因子基因在CMML阶段51%的样本中VAF较高（>35%），进展过程中60%的VAF保持稳定。剪接体基因在CMML阶段70%的样本中VAF较高（>35%），进展过程中61%保持稳定。激活的信号基因在进展过程中出现获得或缺失。TET2突变通常是起始克隆，SRSF2、ASXL1、DNMT3A、EZH2或剪接体基因也可作为始祖突变。RUNX1突变通常是较晚发生的事件，偶尔是始祖突变或种系突变。在sAML进展过程中，通过线性或分支进化获得了细胞遗传学改变、信号通路基因（PTPN11、FLT3、NRAS、CBL）或AML定义基因（NPM1、CEBPA、CBFB::MYH11）。在EZH2、CBL、TET2和DNMT3A基因中发现了CN-LOH。CMML诊断时CEBPA突变以及同时存在的双等位基因TET2与NRAS突变是AML进展时间和总生存的危险因素。一种特征性的ASXL1/RUNX1/剪接体/信号基因谱与单核细胞计数0.5 - 1.0×10⁹/L相关。本研究突出了CMML进展过程中克隆结构动态变化的复杂性和异质性，强调了其在发病机制、表型、风险分层和治疗策略中的重要性。© 2025英国和爱尔兰病理学会
