UMLS:C0026764 - FACTA Search

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Query: UMLS:C0026764 (multiple myeloma)
36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report here that cultured human lymphoma cells in the absence of sonicated eosinophils are sensitive to killing by glucose oxidase (beta-D-glucose:oxygen-oxido reductase; EC 1.1.3.4) at concentrations as low as 0.025 microgram/ml, a level that can be rapidly attained in s.c. tumor implants in mice that receive a single nonlethal injection of enzyme. Multiple clonogenic assays were used to measure the survival of human lymphoma cell lines (H9 and ARH-77) cultured for 14 days in complete RPMI 1640 supplemented with exogenous glucose oxidase (0.025-2.5 micrograms/ml) or an immunoconjugate containing glucose oxidase (0.25-25 micrograms/ml) in the presence or absence of catalase (10 micrograms/ml) or an equal number of sonicated human eosinophils with or without supplemental 100 microM Br-, I-, or SCN-. In addition, we used an immunoassay to measure the concentration of glucose oxidase in s.c. implants of the Sp 2/0 myeloma tumor at 0-30 min after an i.v. injection of 50 micrograms of enzyme into 21 BALB/c mice. Doses of glucose oxidase as small as 0.025 microgram/ml killed more than 3 logs of tumor cells. Catalase completely inhibited, and sonicated human eosinophils partially inhibited, the killing by glucose oxidase or immunoconjugate, whereas supplemental halides had no effect. Glucose oxidase i.v. produced levels > 0.04 microgram/g of tumor for 30 min after injection with a peak concentration of 0.079 microgram/g of tumor within 5 min of injection. These results are important because certain human lymphomas contain extensive extracellular deposits of eosinophil peroxidase, thereby making these tumors potentially less susceptible to killing by otherwise therapeutic doses of glucose oxidase.
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PMID:Effects of sonicated eosinophils on the in vitro sensitivity of human lymphoma cells to glucose oxidase. 816 93

Previous studies show that human myeloma-derived cell lines specifically adhere to fibronectin (FN) through very late antigen-4 (VLA-4; alpha 4 beta 1 integrin complex) and RGD-peptide mechanisms, which may contribute to the localization of tumor cells in bone marrow (BM). In these studies, we characterized the adhesion of myeloma-derived cell lines to both normal and myeloma BM stromal cells (BMSCs) and the effect of adhesion on DNA synthesis. Because interleukin-6 (IL-6) plays an important role in the pathogenesis of multiple myeloma, we also examined the effects of tumor cell adhesion on IL-6 secretion by BMSCs. In 51chromium binding assays, the U266, ARH-77, and IM-9 cell lines showed 52% +/- 12%, 55% +/- 6%, and 47% +/- 7% specific adherence, respectively, to normal BMSCs and 74% +/- 4%, 60% +/- 3%, and 61% +/- 6% specific adherence, respectively, to myeloma BMSCs. In contrast, only 12% to 13% specific binding of HS-Sultan cells to BMSCs was noted. The binding of myeloma cells to BMSCs was partially blocked with anti-beta 1 monoclonal antibody (MoAb), anti-beta 2 integrin MoAb, and excess RGD peptide, suggesting multiple mechanisms for the adhesion of myeloma cell lines to BMSCs. Binding of cell lines to FN or myeloma BMSCs did not affect cell line proliferation; however, adhesion of myeloma cell lines to normal BMSCs decreased DNA synthesis, ie, stimulation indices are 0.1 +/- 0.04, 0.2 +/- 0.1, 0.2 +/- 0.07, and 0.1 +/- 0.06 for the adherent non-IL-6-dependent U266, ARH-77, HS-Sultan, and IM-9 cells, respectively (n = 5, P < .01). In contrast, adherence of IL-6-dependent B9 cells increased their proliferation (stimulation index, 3.2 +/- 0.7). Significant (twofold to eightfold) increases in IL-6 secretion were evident in cell line-adherent (> or = 12 hours) normal and myeloma BMSC cultures. Paraformaldehyde fixation of BMSCs before adhesion completely abrogated IL-6 secretion, suggesting that IL-6 secretion was triggered in BMSCs rather than in cell lines. Partial blocking of cell line adhesion to BMSCs, using anti-beta 1 integrin and anti-beta 2 integrin MoAbs and RGD peptide, also partially blocked the triggering of IL-6 secretion by BMSCs. When cell lines were placed in Transwell inserts and then cultured with either normal or myeloma BMSCs, permitting juxtaposition without cell to cell contact between myeloma cell lines and BMSCs, no increase in IL-6 secretion was observed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Adhesion of human myeloma-derived cell lines to bone marrow stromal cells stimulates interleukin-6 secretion. 826 Jul 8

Human multiple myeloma (MM) xenografts have been difficult to establish in athymic mice. We examined the feasibility of establishing human MM xenograft growth in SCID mice following subcutaneous (sc) injection of 1-2 x 10(7) cells from the human plasma cell dyscrasia (PCD) cell lines RPMI 8226 and ARH-77. SC tumors emerged in 67% (6/9) of RPMI 8226- and 6 of 6 ARH-77-injected mice after a latency period of 9-54 days, and reached 19-35 mm in diameter before the mice were sacrificed. RPMI 8226 and ARH-77 primary tumor DNA hybridized positively with the human genome probe Alul-(Blur8), confirming successful engraftment of the human MM cell lines. The RPMI 8226 xenografts comprised predominantly of plasmacytoid cells that expressed the relevant cytoplasmic immunoglobulin (cIg) light chain isotype. Xenografted RPMI 8226 cells also expressed CD10 (CALLA; 44% reactive cells), CD38 (OKTIO; 69%), CD5 (49%), and reacted with the MM monoclonal antibody MM4 (39%). Human MM growth appeared to be localized subcutaneously for both RPMI 8226 and ARH-77 xenografts. There were no detectable metastatic foci in kidney, brain, heart, or bone marrow. Whereas diffuse plasma cell infiltrates were observed in spleen, GI tract, and lung biopsies of tumor-bearing mice, these infiltrates were of host origin according to immunophenotyping and DNA analyses. Neither the originating RPMI 8226 line nor its SCID mouse xenograft expressed Epstein Barr virus (EBV) genome sequences. These observations indicate that both EBV- (RPMI 8226) and EBV+ (ARH-77) cell lines can be successfully propagated in SCID mice.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Heterotransplantation of human multiple myeloma cell lines in severe combined immunodeficiency (SCID) mice. 839 Dec 43

We have successfully engrafted a human multiple myeloma cell line, ARH-77, into C.B. 17 SCID mice. When ARH-77 cells were injected s.c., tumors grew only at the site of inoculation (five of five). When ARH-77 cells were injected i.v. tumors did not grow in any of the mice (zero of five). However, when mice were given gamma-irradiation with 150 rads and then inoculated i.v. with 10(7) ARH-77 cells, 100% (13 of 13) of the mice developed tumors. Hind leg paralysis was observed in 13 of 16 mice as a result of compression of the spinal cord by tumor. Histological analysis demonstrated that myeloma cells proliferated and formed osteolytic lesions (15 of 16) in the vertebrae and bones of the skull (14 of 16). Tumor cells also invaded the brain and meninges (14 of 16), lung (13 of 15), liver (seven of 15), and kidney (two of 15). Flow cytometric analysis demonstrated that the phenotype of 31% of the bone marrow cells in the vertebrae and 79% of s.c. tumor cells was similar to ARH-77 cells (CD38+, PCA-1+, HLA-Classes 1 and II+). Furthermore, DNA hybridization with a human AluI probe confirmed their human origin. ARH-77-derived human immunoglobulin was detected in the serum of SCID/ARH-77 mice by ELISA. These observations demonstrate systemic involvement of human multiple myeloma following i.v. injection of ARH-77 cells into irradiated mice. This in vivo model should be useful for evaluating new therapeutic modalities for myeloma.
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PMID:Disseminated growth of a human multiple myeloma cell line in mice with severe combined immunodeficiency disease. 844 18

The effect of in vitro exposure to vincristine, Adriamycin, and glucocorticoids was studied in 4 human myeloma cell lines. The drug concentrations tested approximated the steady-state plasma level achievable clinically. Marked growth inhibition was seen in all 4 cell lines with vincristine, but in only 2 with Adriamycin. Glucocorticoids were only minimally inhibitory. The inhibition by glucocorticoids was reversible after drug removal, but that by vincristine and Adriamycin was sustained except the vincristine inhibition of ARH-77 cells. The degree of cell growth inhibition paralleled the reduction in tumor cell 3H-thymidine uptake. Cell cycle distribution analysis showed an arrest of myeloma cells at M/G2 phase by vincristine and Adriamycin and an inhibition of myeloma cells from entering into S phase by dexamethasone. Dose-response analysis with ARH-77 cells, a cell line that appeared the most chemoresistant, showed that the growth-inhibitory effect of Adriamycin and vincristine was roughly proportional to the product of drug concentration and exposure time. However, in contrast to Adriamycin, an effective vincristine concentration and exposure time that totally inhibited cell growth was unable to prevent cell regrowth after drug removal. A higher vincristine concentration appeared to be more effective in preventing cell regrowth.
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PMID:Effect of vincristine, adriamycin and glucocorticoids on myeloma cells in vitro. 850 45

Osteolytic bone destruction and its complications, such as hypercalcemia, pathologic fractures and nerve compression, are the major source of morbidity in patients with multiple myeloma (MM). The bone destruction in MM is due to increased osteoclast activity, but the mechanisms responsible are not entirely clear. We have utilized a human plasma cell leukemia cell line, ARH-77, that has disseminated growth in mice with severe combined immunodeficiency (SCID) and expresses immunoglobulin G kappa (IgG kappa), as a model for human MM. Fifteen SCID mice were irradiated with 400R and 10 of these were injected with 10(6) ARH-77 cells i.v., 24 h after irradiation. Five mice were used as a control group. Development of bone disease was assessed by blood calcium levels, x-rays and histology. Seven out of seven mice that survived irradiation and received ARH-77 cells developed hind limb paralysis 28-35 days after injection. One hundred percent of these mice developed hypercalcemia (1.35-1.46 mmol/l), a mean of five days after becoming paraplegic. Lytic bone lesions were detected by x-ray in all the hypercalcemic mice examined. No lytic lesions or hypercalcemic developed in the controls. Mice were then sacrificed after developing hypercalcemia. Histologic examination of the ARH-77 mice showed infiltration of myeloma cells in the liver and spleen. Marked infiltration by the tumor was found in vertebrae and long bones, with loss of bony trabeculae and increased osteoclast numbers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:An in vivo model of human multiple myeloma bone disease. 852 May 11

Multiple myeloma is a plasma cell malignancy which is generally incurable in spite of a high initial response to chemotherapy. While animal models of myeloma are known, the recent developments of human xenografts in nude and SCID mice suggests a promising experimental model. The SCID model, in particular, holds promise because these animals readily accept hematopoietic and lymphoid transplantation and do not generally develop graft versus host reaction. We have developed two drug-resistant variants of the human multiple myeloma cell line ARH-77 by in vitro exposure to gradually increasing concentrations of doxorubicin (ARH-D60) or mitoxantrone (ARM-80). When injected into irradiated SCID mice, the ARH-D60 cell line grew in an orthotopic pattern with the development of osteolytic lesions. This is in contrast to the 8226/C1N human myeloma cell line which grows in a disseminated but nonorthotopic manner in the SCID mouse. Both the ARH-D60 and ARM-80 cell lines are resistant to doxorubicin and cross-resistant to mitoxantrone, vinca alkaloids, taxol and m-AMSA while maintaining sensitivity to antimetabolites and alkylating agents. Growth characteristics and cell cycle kinetics, including S-phase, were not altered in the resistant sublines. The ARH-D60 and ARM-80 cell lines both displayed a classic multidrug-resistance (MDR) phenotype which was partially reversed by the addition of verapamil. These two cell lines represent the first MDR human myeloma cell lines which have demonstrated an orthotopic growth pattern in the SCID mouse and thus may be of value in studying the pathophysiology of this disease.
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PMID:Development of an orthotopic SCID mouse-human tumor xenograft model displaying the multidrug-resistant phenotype. 854 75

Adhesion of multiple myeloma (MM) cells to bone marrow stromal cells (BMSCs) not only localizes MM cells in the marrow microenvironment, but also triggers interleukin-6 (IL-6) secretion by BMSCs and related MM cell proliferation. In the present study, we characterized the regulation of IL-6 gene expression in BMSCs during MM cell adhesion. Adhesion of ARH-77, HS-Sultan, IM-9, and U266 MM cell lines to BMSCs and BMSC lines (LP 101 and AA 101) triggered 5-through 15-fold and 2-through 4-fold increases in IL-6 secretion, respectively. IL-6 mRNA transcripts were undetectable by Northern blotting in IM-9 MM cells or LP 101 BMSCs cultured alone; however, adherence of IM-9 cells to LP 101 cells induced a transient increase in IL-6 transcripts at 6 hours, followed by peak IL-6 secretion at 24 hours. To confirm increased IL-6 transcription and characterize its regulation, LP101 BMSCs were transiently transfected with full length and deletion fragments of the IL-6 promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene. Transient transfection of LP101 BMSCs with plasmid containing an intact NF-kappa B site showed a 6.8 +/- 0.4-fold increase in CAT activity triggered by IM-9 MM cell adhesion (n = 3, P < .05). Transfection of LP 101 cells with plasmid containing a single base pair deletion from the NF-kapp B binding motif abolished the MM adhesion-induced increase in CAT activity, whereas transfection with plasmid containing three copies of synthetic NF-kappa B sequence resulted in an 8.1 +/- 0.7-fold increase in CAT activity related to MM adhesion (n = 3, P < .05). These data suggest that the NF-kappa B site is one of the essential regulatory elements for MM cell adhesion-induced IL-6 transcription in BMSCs. Electrophoretic mobility shift assays confirmed the involvement of NF-kappa B activation in regulating MM adhesion-induced IL-6 transcription in BMSCs. Further characterization of the upstream events in the signalling cascade regulating IL-6 may not only delineate mechanisms of IL-6 regulation during paracrine MM cell growth, but also provide new therapeutic strategies based on interruption of IL-6 mediated tumor cell growth.
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PMID:Multiple myeloma cell adhesion-induced interleukin-6 expression in bone marrow stromal cells involves activation of NF-kappa B. 856 36

Osteolytic bone destruction and its complications, bone pain, pathologic fractures, and hypercalcemia, are a major source of morbidity and mortality in patients with multiple myeloma. The bone destruction in multiple myeloma is due to increased osteoclast (OCL) activity and decreased bone formation in areas of bone adjacent to myeloma cells. The mechanisms underlying osteolysis in multiple myeloma in vivo are unclear. We used a human plasma cell leukemia cell line, ARH-77, that has disseminated growth in mice with severe combined immunodeficiency (SCID) and expresses IgG kappa, as a model for human multiple myeloma, SCID mice were irradiated with 400 rads and mice were injected either with 10(6) ARH-77 cells intravenously (ARH-77 mice) or vehicle 24 hours after irradiation. Development of bone disease was assessed by blood ionized calcium levels, x-rays, and histology. All ARH-77, but none of control mice that survived irradiation, developed hind limb paralysis 28 to 35 days after injection and developed hypercalcemia (1.35 to 1.46 mmol/L) a mean of 5 days after becoming paraplegic. Lytic bone lesions were detected using x-rays in all the hypercalcemic mice examined. No lytic lesions or hypercalcemia developed in the controls. Controls or ARH-77 mice, after developing hypercalcemia, were then killed and bone marrow plasma from the long bones were obtained, concentrated, and assayed for bone-resorbing activity. Bone marrow plasma from ARH-77 mice induced significant bone resorption in the fetal rat long bone resorption assay when compared with controls (percentage of total 45Ca released = 35% +/- 4% v 11% +/- 1%). Histologic examination of tissues from the ARH-77 mice showed infiltration of myeloma cells in the liver and spleen and marked infiltration in vertebrae and long bones, with loss of bony trabeculae and increased OCL numbers. Interestingly, cultures of ARH-77 mouse bone marrow for early OCL precursors (colony-forming unit-granulocyte-macrophage [CFU-GM]) showed a threefold increase in CFU-GM from ARH-77 marrow versus controls (185 +/- 32 v 40 +/- 3 per 2 x 10(5) cell plated). Bone-resorbing human and murine cytokines such as interleukin-6 (IL-6), IL-1 alpha or beta, TGF-alpha, lymphotoxin, and TNF alpha were not significantly increased in ARH-77 mouse sera or marrow plasma, compared with control mice, although ARH-77 cells produce IL-6 and lymphotoxin in vitro. Conditioned media from ARH-77 cells induced significant bone resorption in the fetal rat long bone resorption assay when compared with untreated media (percentage of total 45Ca released = 22% +/- 2% v 11% +/- 1%). This effect was not blocked by anti-IL-6 or antilymphotoxin (percentage of total 45Ca released = 19% +/- 1% and 22% +/- 1%, respectively). Thus, we have developed a model of human multiple myeloma bone disease that should be very useful to dissect the pathogenesis of the bone destruction in multiple myeloma.
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PMID:Development of an in vivo model of human multiple myeloma bone disease. 860 40

The chemotaxis of human malignant plasma cells is promoted by two extracellular matrix proteins (ECMs): fibronectin (FN) and laminin (LN). We examined the effect of the supernatant from a bone marrow stroma cell line, KM-101, on the chemotaxis of human malignant plasma cell lines to assess the chemotaxis-regulatory roles of the bone marrow microenvironment. Five human malignant plasma cell lines, FR4ds, OPM-1ds, U266/B1, RPMI-8226 and ARH-77 showed different profiles of the expression of beta 1 integrins of FN and LN receptors. FR4ds, OPM-1ds and U266/B1 cells showed chemotaxis promoted by FN (ChFN) and LN (ChLN). ARH-77 cells showed ChFN but not ChLN. RPMI-8226 cells did not show either ChFN or ChLN. The supernatant from KM-101 cells inhibited the chemotaxis of each of these cell lines regardless of whether the chemotaxis was promoted by FN or LN. Among the cytokines produced by KM-101 cells, it was postulated that IL-6 mediated this inhibitory effect because anti-IL-6 monoclonal antibody (MoAb) and anti-IL-6 receptor MoAb significantly reversed the inhibition. Recombinant IL-6 (rIL-6) also exhibited a similar inhibitory effect. Because anti-gp130 MoAb significantly reversed the chemotaxis inhibitory effect of rIL-6, the inhibitory signal is probably transduced via the signal transducing receptor component, gp130. The chemotaxis-regulatory effect is another previously unrecognized function of this pleiotropic cytokine, IL-6. High levels of IL-6 in the bone marrow microenvironment of patients with multiple myeloma appears to be favourable for the localization of myeloma cells there.
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PMID:Interleukin-6 inhibits the chemotaxis of human malignant plasma cell lines. 865 70

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