Leukemia-initiating HSCs in chronic lymphocytic leukemia reveal clonal leukemogenesis and differential drug sensitivity

Cell Rep. 2022 Jul 19;40(3):111115. doi: 10.1016/j.celrep.2022.111115.

Abstract

The existence of "leukemia-initiating cells" (LICs) in chronic lymphocytic leukemia (CLL) remains controversial due to the difficulty in isolating and identifying the tumor-initiating cells. Here, we demonstrate a microchannel electroporation (MEP) microarray that injects RNA-detecting probes into single live cells, allowing the imaging and characterization of heterogeneous LICs by intracellular RNA expression. Using limited-cell FACS sequencing (LC-FACSeq), we can detect and monitor rare live LICs during leukemogenesis and characterize their differential drug sensitivity. Disease-associated mutation accumulation in developing B lymphoid but not myeloid lineage in CLL patient hematopoietic stem cells (CLL-HSCs), and development of independent clonal CLL-like cells in murine patient-derived xenograft models, suggests the existence of CLL LICs. Furthermore, we identify differential protein ubiquitination and unfolding response signatures in GATA2high CLL-HSCs that exhibit increased sensitivity to lenalidomide and resistance to fludarabine compared to GATA2lowCLL-HSCs. These results highlight the existence of therapeutically targetable disease precursors in CLL.

Keywords: CP: Cancer; GATA2; IKZF1; LC-FACSeq; chronic lymphocytic leukemia; fludarabine; lenalidomide; leukemia initiating cells; single-cell analysis; stem cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cells, Cultured
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Leukemia, Lymphocytic, Chronic, B-Cell* / genetics
  • Leukemia, Lymphocytic, Chronic, B-Cell* / metabolism
  • Mice
  • Neoplastic Stem Cells / metabolism
  • RNA / metabolism

Substances

  • RNA