Extracellular vesicles mediate the communication between multiple myeloma and bone marrow microenvironment in a NOTCH dependent way

Haematologica. 2022 Sep 1;107(9):2183-2194. doi: 10.3324/haematol.2021.279716.

Abstract

Multiple myeloma (MM) is an incurable hematologic neoplasm, whose poor prognosis is deeply affected by the propensity of tumor cells to localize in the bone marrow (BM) and induce the protumorigenic activity of normal BM cells, leading to events associated with tumor progression, including tumor angiogenesis, osteoclastogenesis, and the spread of osteolytic bone lesions. The interplay between MM cells and the BM niche does not only rely on direct cell-cell interaction, but a crucial role is also played by MM-derived extracellular vesicles (MM-EV). Here, we demonstrated that the oncogenic NOTCH receptors are part of MM-EV cargo and play a key role in EV protumorigenic ability. We used in vitro and in vivo models to investigate the role of EV-derived NOTCH2 in stimulating the protumorigenic behavior of endothelial cells and osteoclast progenitors. Importantly, MM-EV can transfer NOTCH2 between distant cells and increase NOTCH signaling in target cells. MM-EV stimulation increases endothelial cell angiogenic ability and osteoclast differentiation in a NOTCH2-dependent way. Indeed, interfering with NOTCH2 expression in MM cells may decrease the amount of NOTCH2 also in MM-EV and affect their angiogenic and osteoclastogenic potential. Finally, we demonstrated that the pharmacologic blockade of NOTCH activation by γ-secretase inhibitors may hamper the biological effect of EV derived by MM cell lines and by the BM of MM patients. These results provide the first evidence that targeting the NOTCH pathway may be a valid therapeutic strategy to hamper the protumorigenic role of EV in MM as well as other tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Marrow / pathology
  • Endothelial Cells / metabolism
  • Extracellular Vesicles* / metabolism
  • Humans
  • Multiple Myeloma* / pathology
  • Tumor Microenvironment

Grants and funding

Funding: This study was supported by grants from Associazione Italiana Ricerca sul Cancro, Investigator Grant to RC (20614), My First Grant to AP (18714); Fondazione Italiana per la Ricerca sul Cancro to MC (post-doctoral fellowship 18013); Università degli Studi di Milano to RC (Linea 2B-2017 -Dept. Health Sciences), to NP (postdoctoral fellowship type A) and DG (PhD fellowship in experimental medicine).