Multiple myeloma derived extracellular vesicle uptake by monocyte cells stimulates secretion of IL-6 and MMP9 and promotes cancer cell migration and proliferation.

ABSTRACT: Multiple Myeloma (MM) is an incurable haematological malignancy caused by uncontrolled growth of plasma cells. MM pathogenesis is largely attributed to crosstalk between plasma cells and the bone marrow microenvironment (BMM), where extracellular vesicles (EVs) are reported to play a role. Improved knowledge of the signals mediated by EVs is important to understand MM progression. In this study, EVs secreted from a panel of MM cell lines were isolated by ultracentrifugation. Fluorescently stained EVs were cultured with THP1 monocyte cells and EV uptake by monocytes was determined by flow cytometry and confocal microscopy. MM EVs from three cell lines displayed a differential yet dose dependent uptake by THP1 cells, with H929 EVs displaying greatest EV uptake compared to MM1.s and U266 EVs suggesting that uptake efficiency is dependent on the cell line of origin. Furthermore, MM EVs increased the secretion of MMP9 and IL6 from monocytes, with H929 EVs inducing greater effect, which is consistent with greater uptake efficiency. Moreover, monocyte conditioned media collected following H929 EV uptake significantly increased the migration and proliferation of MM cells indicating that MM EVs can modify the BMM towards a pro-tumourigenic and metastatic phenotype. Finally, mass spectrometry revealed different protein cargo within the MM EVs. Proteomic comparison between the MM-EVs indicated a correlation with proteins involved in exocytic secretion (RAB8b, Exoc4), splicing (FUS, SRPK2) and focal adhesion (integrins ITGB1, ITGA4) that are associated with disease progression. KEGG pathway analysis demonstrated a significant enrichment of spliceosome related proteins in H929 EVs compared to the U266 and MM1s EVs, which may contribute towards the altered BMM. Overall, our results indicate that MM derived EVs modulate monocyte function to promote tumour growth and metastasis.

INSTRUMENT(S): timsTOF Pro

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Monocyte, Cell Culture, Lymphocyte

DISEASE(S): Multiple Myeloma

SUBMITTER: Kieran Wynne  

LAB HEAD: Prof Margaret McGee

PROVIDER: PXD047285 | Pride | 2024-08-26

REPOSITORIES: Pride