Establishment and Characterization of an Epstein-Barr Virus-negative B-cell Line from a Patient with Dissemination of Peripheral Blood and Bone Marrow by Malignant Lymphoid Cell

ABSTRACT

A human malignant lymphoid cell line(JeKo-1) was established from a Korean patient with retroperitoneal tumor presenting peripheral blood and bone marrow involvement by malignant lymphoid cells. This cell line was established from peripheral blood, and the cell line had the identical immunophenotypic features as malignant cells from the peripheral blood. The established cell line had features of a mature B-cell phenotype with no evidence for commitment to other lineages. The JeKo-1 grows in suspension with a doubling time of 33 hours. By light and electron microscopic examination, the established cells had a follicular center showing, a small, cleaved, lymphoid appearance, and had a large amount of cytoplasm containing few vacuoles and an irregular cytoplasmic membrane. Immunophenotypic analyses with monoclonal antibodies using flow cytometry showed a monoclonal IgM kappa and CD5- B-cell phenotype. The cells were non-reactive for T-cells and myeloid/monocyte antigens, and no evidence of Epstein-Barr virus nuclear antigen by polymerase chain reaction. DNA analysis showed a hypodiploid stemline with a DNA index of 0.83. The established cells were strongly reactive for bcl-2 and c-myc onco-protein, but lacked expression of multidrug resistance gene protein, p-glycoprotein by Western blot analysis. Karyotypic analysis of JeKo-1 showed 40-41 chromosomes. This cell line should be a valuable tool to study the dissemination of malignant lymphoma into the peripheral blood and bone marrow.