Establishment and characterization of a human myeloma cell line (KMM‐1)

Abstract

A new cell line (KMM‐1) was established from a subcutaneous plasmacytoma of a 62‐year‐old male with multiple myeloma. Immunological studies indicated that cultured cells were derived from the same clone of myeloma cells in vivo: smeared cells were stained with fluoresceinconjugated globulin of antisera monospecific to lambdachain, and lambda‐chains in the cell extracts and in culture media were identical to the Bence‐Jones protein found in the patient's urine. The cell line grew in suspension with a doubling time of 36‐40 h and contained primitive plasmablastoid cells with prominent nucleoli and rough endoplasmic reticulum. Cells had the karyotype of 47, X, ‐Y. lq+, ‐2, +t(1:2) (cen:cen), +7, 12q+, 14q+, +mar and carried no Epstein‐Barr virus‐determined nuclear antigen. Surface markers were as follows; E rosette (‐), IgG Fc receptor (‐), C3 receptor (‐), S‐lg (+), TdT (‐), asialo‐GM, (‐). The reasons for the successful establishment of the myeloma cell line are discussed.