datasheet1_miRNome profiling of LSC-enriched CD34+CD38−CD26+ fraction in Ph+ CML-CP samples from Argentinean patients: a potential new pharmacogenomic tool.pdf

Chronic myeloid leukemia (CML) is a myeloid stem cell neoplasm characterized by an expansion of myeloid progenitor cells and the presence of BCR-ABL1 oncoprotein. Since the introduction of specific BCR-ABL1 tyrosine kinase inhibitors (TKI), overall survival has improved significantly. However, under long-term therapy patients may have residual disease that originates from TKI-resistant leukemic stem cells (LSC). In this work, we analyzed the miRNome of LSC-enriched CD34+CD38−CD26+ and normal hematopoietic stem cells (HSC) fractions obtained from the same chronic phase (CP) CML patients, and stem and progenitor cells obtained from healthy donors (HD) by next-generation sequencing. We detected a global decrease of microRNA levels in LSC-enriched CD34+CD38−CD26+ and HSC fractions from CML-CP patients, and decreased levels of microRNAs and snoRNAs from a genomic cluster in chromosome 14, suggesting a mechanism of silencing of multiple non-coding RNAs. Surprisingly, HSC from CML-CP patients, despite the absence of BCR-ABL1 expression, showed an altered miRNome. We confirmed by RT-qPCR that the levels of miR-196a-5p were increased more than nine-fold in CD26+ (BCR-ABL1+) vs. CD26− (BCR-ABL1−) CD34+CD38− fractions from CML-CP patients at diagnosis, and in silico analysis revealed a significant association to lipid metabolism and hematopoiesis functions. In the light of recent descriptions of increased oxidative metabolism in CML LSC-enriched fractions, these results serve as a guide for future functional studies that evaluate the role of microRNAs in this process. Metabolic vulnerabilities in LSCs open the road for new therapeutic strategies. This is the first report of the miRNome of CML-CP CD34+CD38− fractions that distinguishes between CD26+ (BCR-ABL1+) and their CD26− (BCR-ABL1-) counterparts, providing valuable data for future studies.

慢性髓性白血病（Chronic myeloid leukemia, CML）是一类髓系干细胞肿瘤，以髓系祖细胞扩增及BCR-ABL1癌蛋白表达为特征。自特异性BCR-ABL1酪氨酸激酶抑制剂（tyrosine kinase inhibitors, TKI）投入临床以来，患者总生存期得到显著改善。然而，长期接受TKI治疗的患者可能出现残留病灶，其来源为TKI耐药的白血病干细胞（leukemic stem cells, LSC）。
本研究通过二代测序（next-generation sequencing），分析了来自同一慢性期（chronic phase, CP）CML患者的、富集LSC的CD34+CD38−CD26+组分与正常造血干细胞（hematopoietic stem cells, HSC）组分，以及健康供者（healthy donors, HD）来源的干细胞与祖细胞的微小RNA组（miRNome）。研究发现，CML-CP患者的富集LSC的CD34+CD38−CD26+组分及HSC组分中，微小RNA（microRNA）水平整体下调；同时14号染色体某基因组簇编码的微小RNA与核仁小RNA（small nucleolar RNA, snoRNA）水平降低，提示存在多类非编码RNA的沉默机制。
令人意外的是，尽管CML-CP患者的HSC不表达BCR-ABL1，但其微小RNA组仍发生了显著改变。通过逆转录实时定量PCR（RT-qPCR）验证，确诊时CML-CP患者的CD26+（BCR-ABL1+）CD34+CD38−组分中，miR-196a-5p的表达水平较CD26−（BCR-ABL1−）组分升高9倍以上；计算机模拟分析（in silico analysis）显示，该miRNA与脂质代谢及造血功能显著相关。
结合近期关于CML富集LSC组分氧化代谢增强的研究报道，本研究结果可为后续探究微小RNA在该过程中作用的功能研究提供重要指引。白血病干细胞的代谢脆弱性为新型治疗策略的开发开辟了路径。本研究首次报道了区分CD26+（BCR-ABL1+）与CD26−（BCR-ABL1−）对应组分的CML-CP CD34+CD38−组分的微小RNA组数据，可为后续相关研究提供宝贵的参考资料。