Single-cell proteo-transcriptomic profiling reveals altered characteristics of stem and progenitor cells in patients receiving cytoreductive hydroxyurea in early-phase chronic myeloid leukemia

Haematologica. 2025 Jan 1;110(1):117-128. doi: 10.3324/haematol.2024.285071.

Abstract

Hydroxyurea (HU) is frequently used in the early phase of chronic myeloid leukemia (CML) to achieve cytoreduction prior to tyrosine kinase inhibitor therapy. However, its impact on CML stem and progenitor cells (SPC) remains largely unknown. This study utilized targeted proteo-transcriptomic expression data on 596 genes and 51 surface proteins in 60,000 CD14-CD34+ cells from chronic phase CML patients to determine effects of short-term HU treatment (4-19 days) on CML SPC. Peripheral blood and bone marrow samples were obtained from 17 CML patients eligible for short-term HU treatment (3 patients before and after HU, 7 patients before HU and 7 patients after HU) and subjected to single-cell CITE-sequencing and/or flow cytometry analysis. The analysis revealed enhanced frequencies of hemoglobin-expressing (HBA1, HBA2, HBB) erythroid progenitor cells in blood and bone marrow following HU treatment. In addition, there was an accumulation of cell subsets with S/G2/M phase-related gene and protein expression, likely representing cells arrested in, or progressing slowly through, the cell cycle. The increased frequency of cells in S/G2/M phase after HU was observed already among the most immature leukemic stem cells (LSC), and patients with a large fraction of LSC in the S/G2/M phase showed poor responsiveness to tyrosine kinase inhibitor treatment. We conclude that short-term HU treatment entails differentiation of erythroid progenitor cells and alters the characteristics of LSC in CML. The results imply that studies of LSC and progenitor populations in CML should take effects of initial HU therapy into account.

MeSH terms

  • Adult
  • Aged
  • Female
  • Gene Expression Profiling*
  • Humans
  • Hydroxyurea* / administration & dosage
  • Hydroxyurea* / pharmacology
  • Hydroxyurea* / therapeutic use
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / diagnosis
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology
  • Leukemia, Myeloid, Chronic-Phase / drug therapy
  • Leukemia, Myeloid, Chronic-Phase / genetics
  • Leukemia, Myeloid, Chronic-Phase / pathology
  • Male
  • Middle Aged
  • Neoplastic Stem Cells* / drug effects
  • Neoplastic Stem Cells* / metabolism
  • Neoplastic Stem Cells* / pathology
  • Single-Cell Analysis*
  • Transcriptome

Substances

  • Hydroxyurea

Grants and funding

Funding: This work was supported by grants from the Swedish Research Council (2020-02783 to FBT and 2023-02193 to AM), the Swedish Cancer Society (21 1864 Pj to KH, 22 2388 Pj to FBT and 22 2128 Pj to AM), the Swedish state via the ALF agreement (ALFGBG-718421 to KH, ALFGBG-963642 to FBT and ALFGBG-724881 to AM), the Swedish Childhood Cancer Fund (PR2021-0015 to PJ), the Assar Gabrielsson Foundation and the Sahlgrenska Academy at the University of Gothenburg. The authors received research funding in the form of free reagents from BD Biosciences within the BD Multiomics Alliance.