Differential expression of miR-17~92 identifies BCL2 as a therapeutic target in BCR-ABL-positive B-lineage acute lymphoblastic leukemia

Leukemia. 2014 Mar;28(3):554-65. doi: 10.1038/leu.2013.361. Epub 2013 Nov 27.

Abstract

Despite advances in allogeneic stem cell transplantation, BCR-ABL-positive acute lymphoblastic leukaemia (ALL) remains a high-risk disease, necessitating the development of novel treatment strategies. As the known oncomir, miR-17~92, is regulated by BCR-ABL fusion in chronic myeloid leukaemia, we investigated its role in BCR-ABL translocated ALL. miR-17~92-encoded miRNAs were significantly less abundant in BCR-ABL-positive as compared to -negative ALL-cells and overexpression of miR-17~19b triggered apoptosis in a BCR-ABL-dependent manner. Stable isotope labelling of amino acids in culture (SILAC) followed by liquid chromatography and mass spectroscopy (LC-MS) identified several apoptosis-related proteins including Bcl2 as potential targets of miR-17~19b. We validated Bcl2 as a direct target of this miRNA cluster in mice and humans, and, similar to miR-17~19b overexpression, Bcl2-specific RNAi strongly induced apoptosis in BCR-ABL-positive cells. Furthermore, BCR-ABL-positive human ALL cell lines were more sensitive to pharmacological BCL2 inhibition than negative ones. Finally, in a xenograft model using patient-derived leukaemic blasts, real-time, in vivo imaging confirmed pharmacological inhibition of BCL2 as a new therapeutic strategy in BCR-ABL-positive ALL. These data demonstrate the role of miR-17~92 in regulation of apoptosis, and identify BCL2 as a therapeutic target of particular relevance in BCR-ABL-positive ALL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fusion Proteins, bcr-abl / genetics*
  • Heterografts
  • Humans
  • Leukemia, B-Cell / genetics
  • Leukemia, B-Cell / therapy*
  • Mice
  • MicroRNAs / genetics*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / therapy*
  • Proto-Oncogene Proteins c-bcl-2 / genetics*

Substances

  • MIRN17 microRNA, human
  • MicroRNAs
  • Proto-Oncogene Proteins c-bcl-2
  • Fusion Proteins, bcr-abl