Modeling Myeloma Dissemination In Vitro with hMSC-interacting Subpopulations of INA-6 Cells and Their...

Area of Science:

• Hematology
• Cancer Biology
• Cell Biology

Background:

• Multiple myeloma is characterized by widespread malignant plasma cells in the bone marrow.
• The initial mechanisms driving myeloma cell dissemination remain poorly understood.
• Human bone marrow-derived mesenchymal stromal cells (hMSCs) influence myeloma cell growth and retention.

Purpose of the Study:

• To investigate the in vitro dissemination dynamics of myeloma cells.
• To model the interaction between myeloma cells and hMSCs.
• To identify molecular factors involved in myeloma cell retention and dissemination.

Main Methods:

• Co-culture of INA-6 myeloma cells with primary hMSCs.
• Time-lapse microscopy to observe cell proliferation and attachment/detachment.
• V-well adhesion assay and sandwich centrifugation for subpopulation isolation.
• RNA sequencing, cell viability, and apoptosis assays for characterization.
• Correlation with patient gene expression and survival data.

Main Results:

• Myeloma cells formed aggregates on hMSCs, with daughter cells detaching post-division.
• Heterotypic interactions between hMSCs and myeloma cells modulated apoptosis.
• Isolated daughter cells exhibited enhanced viability and proliferation markers.
• Adhesion and retention factors (e.g., CXCL12) were upregulated in cells with longer survival.

Conclusions:

• In vitro myeloma cell dissemination is driven by daughter cell detachment following proliferation and hMSC interaction.
• Adhesion factors play a crucial role in retaining myeloma cells within the bone marrow microenvironment.
• Identified adhesion mechanisms and genes may represent novel therapeutic targets for multiple myeloma.