Introduction: Multiple myeloma (MM) is still uncurable due to the crosstalk between MM cells and bone barrow (BM) cells. Extracellular vesicles (EVs) play a key role in the pathological communication betweenMMandBM.Notch2 receptor and Jagged1 and 2 are overexpressed in MM, triggering Notch pathway also on BM population and inducing their pro-tumorigenic activity. Here, we investigate the effect of MM-derived EVs in eliciting the pro-tumoral effect of BM in MM progression and the role of vesicular Notch2. Methods: MM cells constitutively inhibited for Notch2 (MMN2KD-EVs) and the shed EVs (MM-EVs) were characterized for Notch receptors by Western blot, for size and number by nanoparticle tracking analysis and electronic transmission microscopy, and for their uptake in recipient cells by confocal and flow cytometry. The transfer of Notch2 via EVs was evaluated by an in vitro system of sending cells expressing HA-tagged Notch2, their EVs and receiving cells. Notch pathway activation was assessed by Notch reporter assays in vitro (HeLa cells) and in vivo (transgenic zebrafish embryos). The pro-tumorigenic effect of MM-EVs and MMN2KD-EVs were evaluated by measuring their osteoclastogenic and angiogenic potential in vitro. To confirm the role of vesicular Notch, the effect of MM-EVs or EVs from the BM of MM patients was assessed in the presence of a g-secretase inhibitor (GSI), which affects Notch activation (Informed consent and IRB of Insubria approval was obtained n. 1/2018.). Results: MM-EVs carry and transfer Notch2 increasing Notch signaling in recipient endothelial cells and osteoclasts. MM-EVs induce the osteoclast formation and angiogenesis in a Notch2 dependent way. GSI effectively decreased the osteoclastogenic and angiogenic potential of MM-EVs in vitro and the angiogenic effect of EV from MM patients’ BM. Summary/Conclusion: These results suggest that targetingNotch pathway may hamper the pro-tumorigenic activity ofMM-EV in the BM.
"The role of Notch2 in osteoclastogenic and angiogenic potential of extracellular vesicles in multiple myeloma" in ISEV2022 Abstract Book
V. Dolo;I. Giusti;
2022-01-01
Abstract
Introduction: Multiple myeloma (MM) is still uncurable due to the crosstalk between MM cells and bone barrow (BM) cells. Extracellular vesicles (EVs) play a key role in the pathological communication betweenMMandBM.Notch2 receptor and Jagged1 and 2 are overexpressed in MM, triggering Notch pathway also on BM population and inducing their pro-tumorigenic activity. Here, we investigate the effect of MM-derived EVs in eliciting the pro-tumoral effect of BM in MM progression and the role of vesicular Notch2. Methods: MM cells constitutively inhibited for Notch2 (MMN2KD-EVs) and the shed EVs (MM-EVs) were characterized for Notch receptors by Western blot, for size and number by nanoparticle tracking analysis and electronic transmission microscopy, and for their uptake in recipient cells by confocal and flow cytometry. The transfer of Notch2 via EVs was evaluated by an in vitro system of sending cells expressing HA-tagged Notch2, their EVs and receiving cells. Notch pathway activation was assessed by Notch reporter assays in vitro (HeLa cells) and in vivo (transgenic zebrafish embryos). The pro-tumorigenic effect of MM-EVs and MMN2KD-EVs were evaluated by measuring their osteoclastogenic and angiogenic potential in vitro. To confirm the role of vesicular Notch, the effect of MM-EVs or EVs from the BM of MM patients was assessed in the presence of a g-secretase inhibitor (GSI), which affects Notch activation (Informed consent and IRB of Insubria approval was obtained n. 1/2018.). Results: MM-EVs carry and transfer Notch2 increasing Notch signaling in recipient endothelial cells and osteoclasts. MM-EVs induce the osteoclast formation and angiogenesis in a Notch2 dependent way. GSI effectively decreased the osteoclastogenic and angiogenic potential of MM-EVs in vitro and the angiogenic effect of EV from MM patients’ BM. Summary/Conclusion: These results suggest that targetingNotch pathway may hamper the pro-tumorigenic activity ofMM-EV in the BM.Pubblicazioni consigliate
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