Blood Cancer Journal (Oct 2024)

The DLEU2/miR-15a/miR-16-1 cluster shapes the immune microenvironment of chronic lymphocytic leukemia

  • Ronghua Zhang,
  • Priyanka Khare,
  • Priyanka Banerjee,
  • Cristina Ivan,
  • Sarah Schneider,
  • Federica Barbaglio,
  • Karen Clise-Dwyer,
  • Vanessa Behrana Jensen,
  • Erika Thompson,
  • Marisela Mendoza,
  • Nicholas Chiorazzi,
  • Shih-Shih Chen,
  • Xiao-Jie Joy Yan,
  • Nitin Jain,
  • Paolo Ghia,
  • Federico Caligaris-Cappio,
  • Rima Mendonsa,
  • Sashi Kasimsetty,
  • Ryan Swoboda,
  • Recep Bayraktar,
  • William Wierda,
  • Varsha Gandhi,
  • George A. Calin,
  • Michael J. Keating,
  • Maria Teresa Sabrina Bertilaccio

DOI
https://doi.org/10.1038/s41408-024-01142-3
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 12

Abstract

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Abstract The development and progression of chronic lymphocytic leukemia (CLL) depend on genetic abnormalities and on the immunosuppressive microenvironment. We have explored the possibility that genetic drivers might be responsible for the immune cell dysregulation that shapes the protumor microenvironment. We performed a transcriptome analysis of coding and non-coding RNAs (ncRNAs) during leukemia progression in the Rag2−/−γc −/− MEC1-based xenotransplantation model. The DLEU2/miR-16 locus was found downmodulated in monocytes/macrophages of leukemic mice. To validate the role of this cluster in the tumor immune microenvironment, we generated a mouse model that simultaneously mimics the overexpression of hTCL1 and the germline deletion of the minimal deleted region (MDR) encoding the DLEU2/miR-15a/miR-16-1 cluster. This model provides an innovative and faster CLL system where monocyte differentiation and macrophage polarization are exacerbated, and T-cells are dysfunctional. MDR deletion inversely correlates with the levels of predicted target proteins including BCL2 and PD1/PD-L1 on murine CLL cells and immune cells. The inverse correlation of miR-15a/miR-16-1 with target proteins has been confirmed on patient-derived immune cells. Forced expression of miR-16-1 interferes with monocyte differentiation into tumor-associated macrophages, indicating that selected ncRNAs drive the protumor phenotype of non-malignant immune cells.