Heterogeneous expression of a novel MPC-1 antigen on myeloma cells: possible involvement of MPC-1 antigen in the adhesion of mature myeloma cells to bone marrow stromal cells

Blood. 1993 Dec 15;82(12):3721-9.


Recent immunophenotypic analysis has shown that the heterogeneous expression of the adhesion molecule VLA-5 classifies myeloma cells into VLA-5+ mature and VLA-5- immature subpopulations. To further clarify the two myeloma subpopulations, we generated a monoclonal antibody, MPC-1, by immunizing mice with an adherent human myeloma cell line, KMS-5. The MPC-1 antibody recognized a 48-Kd surface antigen on KMS-5 but not on U-266, a nonadherent human myeloma cell line. Specificity characterization showed that MPC-1 antigen was expressed on mature myeloma cells, normal plasma cells, and mature B cells, whereas pre-B cells and germinal center B cells lacked its expression. Monocytes and a human bone marrow stromal cell line, KM102, also expressed this antigen. Two subclones of MPC-1+ VLA-5+ (KMS-5Ad) and MPC-1-VLA-5+ (KMS-5NAd) were separated from the KMS-5 cell line. The KMS-5NAd adhered to KM102 more tightly than did the KMS-5NAd, and the U-266 (MPC-1-VLA-5-) displayed almost no adherence to the KM102. The adhesion of the KMS-5Ad was partially inhibited by the MPC-1 antibody. These results, taken together, suggest that the MPC-1 antigen serves as a differentiation marker for B-lineage cells, including plasma cells, and may function as an adhesion molecule involved in the interaction of mature myeloma cells with bone marrow stromal cells.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology
  • Antigens, Surface / analysis
  • Antigens, Surface / biosynthesis
  • Blotting, Western
  • Bone Marrow / physiology*
  • Bone Marrow Cells
  • Cell Adhesion / physiology*
  • Cell Line
  • Clone Cells
  • Flow Cytometry
  • Humans
  • Mice
  • Molecular Weight
  • Monocytes / physiology
  • Multiple Myeloma / pathology
  • Multiple Myeloma / physiopathology*
  • Neoplasm Proteins / analysis
  • Neoplasm Proteins / biosynthesis*
  • Neoplasm Proteins / immunology
  • Receptors, Fibronectin / physiology
  • Tumor Cells, Cultured


  • Antibodies, Monoclonal
  • Antigens, Surface
  • MPC-1 antigen
  • Neoplasm Proteins
  • Receptors, Fibronectin