Multiple myeloma (MM) is a B-cell malignancy characterized by the accumulation, primarily in bone marrow, of a clone of plasma cells. The nature of the stem cells feeding the tumoral compartment is still unknown. To investigate this special point, we have studied the phenotypes of nine well-known human myeloma cell lines (HMCLs) and compared them with those of normal lymphoblastoid cell lines (...

Recent work identifies the AKT kinase as a potential mediator of tumor expansion in multiple myeloma. The finding of PTEN mutations in several myeloma cell lines suggests that loss of PTEN function may be one mechanism by which AKT activity is increased in this disease. Because PTEN-deficient myeloma cells may have up-regulated activity of the mammalian target of rapamycin (mTOR), downstream of...

Chromosomal translocations or DNA rearrangements affecting c-myc occur in almost all murine plasmacytoma and human Burkitt's lymphoma tumors and are associated with a high incidence of exon 2 missense mutations and selective expression of the affected allele. Screening nine multiple myeloma cell lines, we identified no exon 2 missense mutations but did identify two lines with single, silent mut...

The mature myeloma cells express very late antigen 5 (VLA-5) and MPC-1 antigens on their surface and adhere to bone marrow (BM) stromal cells more tightly than the VLA-5-MPC-1- immature myeloma cells in vitro. The VLA-5 and MPC-1 antigens possibly function as two of the molecules responsible for interaction of mature myeloma cells with BM stromal cells. However, the immature myeloma cells do in...

Identification of growth factors in neoplasias may be a target for future therapies by blocking either growth factor–receptor interaction or the induced pathway. Using gene expression profiling, we identified overexpression of two receptors for APRIL and BAFF in malignant plasma cells compared to normal plasma cells. APRIL and BAFF are involved in a variety of tumor and autoimmune diseases, inc...

PURPOSE We tried to establish clinically relevant human myeloma cell lines that can contribute to the understanding of multiple myeloma (MM). MATERIALS AND METHODS Mononuclear cells obtained from MM patient's bone marrow were injected via tail vein in an NRG/SCID mouse. Fourteen weeks after the injection, tumor developed at subcutis of the mouse. The engraftment of MM cells into mouse bone ma...

We have determined the in vitro host range of the cloned MO-21 and FL-1 murine myeloma retroviruses grown in SC-1 cells that were originally isolated from cloned MOPC-21 and FLOPC-1 BALB/c plasmacytoma cell lines. These viruses are able to replicate in murine (BALB/3T3, NIH/3T3) as well as numerous heterologous cell lines. These myeloma retroviruses also exhibit mink cell focus-inducing activit...

MUC1 is a highly immunogenic epithelial mucin and serves as a tumor-associated antigen in breast, pancreatic and ovarian carcinomas. We previously reported the expression of MUC1 on myeloma cells and the establishment of an HLA-unrestricted cytotoxic T lymphocyte (CTL) line TN that recognized MUC1 from peripheral blood mononuclear cells in a multiple myeloma patient. In this study, we attempted...

Imexon is a cyanoaziridine derivative that has antitumor activity in multiple myeloma. Previous studies have shown that imexon induces oxidative stress and apoptosis in the RPMI 8226 myeloma cell line. This study reports that imexon has cytotoxic activity in other malignant cell lines including NCI-H929 myeloma cells and NB-4 acute promyelocytic leukemia cells, whereas normal lymphocytes and U2...

PU.1 is a hematopoietic transcription factor belonging to the Ets-family. It is identical to the Spi-1 oncogene, which is implicated in spleen focus-forming virus-induced murine erythroleukemias. PU.1 seems to be required for early development of multiple hematopoietic lineages, but its expression in mature cells is preferentially observed in cells of the B-cell-and monocyte/macrophage-differen...