In vitro models of the crosstalk between multiple myeloma and stromal cells recapitulate the mild NF-κB activation observed in vivo

• Published in: Cell death & disease Vol. 15; no. 10; pp. 731 - 18
• Main Authors: Colombo, Federica, Guzzeloni, Virginia, Kizilirmak, Cise, Brambilla, Francesca, Garcia-Manteiga, Jose Manuel, Tascini, Anna Sofia, Moalli, Federica, Mercalli, Francesca, Ponzoni, Maurilio, Mezzapelle, Rosanna, Ferrarini, Marina, Ferrero, Elisabetta, Visone, Roberta, Rasponi, Marco, Bianchi, Marco E., Zambrano, Samuel, Agresti, Alessandra
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06-10-2024; Springer Nature B.V; Nature Publishing Group
• Subjects: 13/21; 13/51; 13/62; 14; 14/19; 38; 38/39; 42/47; 631/67/327; 64/60; 692/308/1426; 692/420/256/2515; 96/35; Antibodies; Biochemistry; Biomedical and Life Sciences; Bioreactors; Cell activation; Cell Biology; Cell Communication; Cell Culture; Cell Line, Tumor; Coculture Techniques; Humans; IL-1β; Immunofluorescence; Immunology; Inflammation; Interleukin 1 receptor antagonist; Interleukin-1beta - metabolism; Life Sciences; Mesenchymal stem cells; Mesenchymal Stem Cells - metabolism; Microenvironments; Microfluidics; Multiple myeloma; Multiple Myeloma - genetics; Multiple Myeloma - metabolism; Multiple Myeloma - pathology; NF-kappa B - metabolism; NF-κB protein; Paracrine Communication; Paracrine signalling; Signal Transduction; Stromal cells; Stromal Cells - metabolism; Stromal Cells - pathology; Transcription Factor RelA - metabolism; Tumor Microenvironment; Tumor necrosis factor-α
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-024-07038-1

Multiple myeloma (MM) is linked to chronic NF-κB activity in myeloma cells, but this activity is generally considered a cell-autonomous property of the cancer cells. The precise extent of NF-κB activation and the contributions of the physical microenvironment and of cell-to-cell communications remain largely unknown. By quantitative immunofluorescence, we found that NF-κB is mildly and heterogeneously activated in a fraction of MM cells in human BMs, while only a minority of MM cells shows a strong activation. To gain quantitative insights on NF-κB activation in living MM cells, we combined advanced live imaging of endogenous p65 Venus-knocked-in in MM.1S and HS-5 cell lines to model MM and mesenchymal stromal cells (MSCs), cell co-cultures, microfluidics and custom microbioreactors to mimic the 3D-interactions within the bone marrow (BM) microenvironment. We found that i) reciprocal MM-MSC paracrine crosstalk and cell-to-scaffold interactions shape the inflammatory response in the BM; ii) the pro-inflammatory cytokine IL-1β, abundant in MM patients’ plasma, activates MSCs, whose paracrine signals are responsible for strong NF-κB activation in a minority of MM cells; iii) IL-1β, but not TNF-α, activates NF-κB in vivo in BM-engrafted MM cells, while its receptor inhibitor Anakinra reduces the global NF-κB activation. We propose that NF-κB activation in the BM of MM patients is mild, restricted to a minority of cells and modulated by the interplay of restraining physical microenvironmental cues and activating IL-1β-dependent stroma-to-MM crosstalk.