Bone Marrow Myeloma Cells Research Articles

Granulocyte-Macrophage Colony-Stimulating Factor Synergizes With Interleukin-6 in Supporting the Proliferation of Human Myeloma Cells

AbstractThe role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the growth of multiple myeloma (MM) was investigated in 21 patients with MM. In 17 patients with proliferating myeloma cells in vivo, recombinant GM-CSF significantly increased the endogenous-IL-6-mediated spontaneous myeloma cell proliferation occurring in 5-day cultures of tumor cells in vitro (P <.01). Furthermore, GM-CSF was detected in 5-day culture supernatants of myeloma bone marrow cells. This endogenous GM-CSF was produced by the myeloma bone marrow microenvironment but not by myeloma cells and contributed to the spontaneous myeloma-cell proliferation observed in 5-day cultures. In fact, this proliferation was partially blocked (67%) by anti-GM-CSF monoclonal antibodies. The stimulatory effect of rGM-CSF was mediated through IL-6 because it was abrogated by anti-IL-6 monoclonal antibodies. rGM-CSF did not reproducibly increase the endogenous IL-6 production in short-term cultures of bone marrow cells of MM patients. Using an IL-6-dependent myeloma cell line (XG-1 cell line), rGM-CSF was shown to act directly on myeloma cells stimulating by twofold their IL-6 responsiveness. rGM-CSF did not induce any IL-6 production in XG-1 cells, nor was it able to sustain their growth alone. Although no detectable GM-CSF levels were found in the peripheral or bone marrow blood of MM patients, it is possible that GM-CSF, produced locally by the tumoral environment, enhances the IL-6 responsiveness of myeloma cells in vivo in a way similar to that reported here in vitro.

Granulocyte-macrophage colony-stimulating factor synergizes with interleukin-6 in supporting the proliferation of human myeloma cells [see comments

The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the growth of multiple myeloma (MM) was investigated in 21 patients with MM. In 17 patients with proliferating myeloma cells in vivo, recombinant GM-CSF significantly increased the endogenous-IL-6-mediated spontaneous myeloma cell proliferation occurring in 5-day cultures of tumor cells in vitro (P less than .01). Furthermore, GM-CSF was detected in 5-day culture supernatants of myeloma bone marrow cells. This endogenous GM-CSF was produced by the myeloma bone marrow microenvironment but not by myeloma cells and contributed to the spontaneous myeloma-cell proliferation observed in 5-day cultures. In fact, this proliferation was partially blocked (67%) by anti-GM-CSF monoclonal antibodies. The stimulatory effect of rGM-CSF was mediated through IL-6 because it was abrogated by anti-IL-6 monoclonal antibodies. rGM-CSF did not reproducibly increase the endogenous IL-6 production in short-term cultures of bone marrow cells of MM patients. Using an IL-6-dependent myeloma cell line (XG-1 cell line), rGM-CSF was shown to act directly on myeloma cells stimulating by twofold their IL- 6 responsiveness. rGM-CSF did not induce any IL-6 production in XG-1 cells, nor was it able to sustain their growth alone. Although no detectable GM-CSF levels were found in the peripheral or bone marrow blood of MM patients, it is possible that GM-CSF, produced locally by the tumoral environment, enhances the IL-6 responsiveness of myeloma cells in vivo in a way similar to that reported here in vitro.

Detection of interleukin-6 (IL-6) in human bone marrow myeloma cells by light and electron microscopy

We used an Avidin-Biotin peroxidase complex (ABC) immunoperoxidase technique to evaluate the localization of IL-6 of human bone marrow cells in multiple myeloma (MM). The cellular distribution of IL-6 was determined at light and electron microscopic levels. The author's study indicated that cytoplasmic IL-6 was detected only in the myeloma cells of bone marrow cells. Immunoelectron microscopic (immuno-EM) study showed positive reactivity mainly in the perinuclear space (PNS), well-developed rough endoplasmic reticulum (RER), and Golgi area.

Peripheral blood and bone marrow lymphocyte subsets in patients with multiple myeloma

A panel of monoclonal antibodies (McAb) from the Wu series was used to characterize lymphocyte subsets of peripheral blood (PB) from 9 patients with multiple myeloma (MM) by means of indirect immunofluorescence assay. In 7 of these patients bone marrow (BM) cells were also studied. Abnormal distribution of T lymphocyte subsets was observed in these patients, and the alterations were quite similar in both PB and BM. A significant increase in the proportion of WUT8+ cells (P less than 0.001) and a reduced WuT4/WuT8 ratio (P less than 0.001) were found in patient group. In both PB and BM of patients, WuT10+ cell counts were significantly higher than normal (P less than 0.001). There was a good correlation between BM WuT10+ cells and BM myeloma cells (r = 0.76, P less than 0.05), whereas no correlation was found between PB WuT10+ cells and BM myeloma cells. The significance of abnormal T-cell subset distribution and elevated WuT10+ cells in MM is discussed.

Production of cytokines by bone marrow cells obtained from patients with multiple myeloma

Previous work with continuously cultured multiple myeloma lines suggested that cytokine production by tumor cells may mediate some of the medical complications of this disease. To further investigate this issue, we assayed freshly obtained bone marrow (BM) cells from myeloma patients for the in vitro production of cytokines and the presence of cytokine RNA. Production of cytokine protein was assessed by bioassays with the aid of specific neutralizing anticytokine antibodies. These assays detected interleukin-1 (IL-1) and tumor necrosis factor (TNF) secretion by myeloma BM cells, which was significantly greater than secretion from similarly processed BM cells of control individuals. In contrast, lymphotoxin and interleukin-2 (IL-2) production could not be detected. The levels of IL-1 and TNF produced in vitro peaked at 24 hours of culture and correlated with stage and the presence (or absence) of extensive osteolytic bone disease. Northern blot analysis demonstrated the presence of IL-1 beta and TNF RNA in uncultured myeloma BM cells but no detectable IL-1 alpha or lymphotoxin RNA. In addition, the amount of cytokine RNA correlated with protein production, being significantly greater in patients' BM cells than in control marrow. These data suggest a role for IL-1 beta and/or TNF in the pathophysiology of multiple myeloma and argue against a role for lymphotoxin or IL-2.

Production of Cytokines by Bone Marrow Cells Obtained From Patients With Multiple Myeloma

Previous work with continuously cultured multiple myeloma lines suggested that cytokine production by tumor cells may mediate some of the medical complications of this disease. To further investigate this issue, we assayed freshly obtained bone marrow (BM) cells from myeloma patients for the in vitro production of cytokines and the presence of cytokine RNA. Production of cytokine protein was assessed by bioassays with the aid of specific neutralizing anticytokine antibodies. These assays detected interleukin-1 (IL-1) and tumor necrosis factor (TNF) secretion by myeloma BM cells, which was significantly greater than secretion from similarly processed BM cells of control individuals. In contrast, lymphotoxin and interleukin-2 (IL-2) production could not be detected. The levels of IL-1 and TNF produced in vitro peaked at 24 hours of culture and correlated with stage and the presence (or absence) of extensive osteolytic bone disease. Northern blot analysis demonstrated the presence of IL-1 beta and TNF RNA in uncultured myeloma BM cells but no detectable IL-1 alpha or lymphotoxin RNA. In addition, the amount of cytokine RNA correlated with protein production, being significantly greater in patients' BM cells than in control marrow. These data suggest a role for IL-1 beta and/or TNF in the pathophysiology of multiple myeloma and argue against a role for lymphotoxin or IL-2.

Production of interleukin-1 by bone marrow myeloma cells

Plasma cells isolated from bone marrow (BM) aspirates of 12 patients with multiple myeloma (MM) and nine patients with monoclonal gammopathy of undetermined significance (MGUS) were analyzed for production of cytokines with bone-resorbing activity, such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and lymphotoxin (LT). Culture supernatants of plasma cells from MM, but not from MGUS or normal donor, invariably contained high amounts of IL-1-beta and lower amounts of IL-1-alpha. With a single exception, TNF/LT biologic activity was not detected in the same supernatants. IL-6 was present in two of five supernatants tested. Normal B lymphocytes released both IL-1 and TNF/LT activities for four days after activation in vitro; however, production of these cytokines ceased at the final stage of plasma cell. Unexpectedly, the mRNA extracted from MM plasma cell hybridized with TNF- and LT- specific, as well as IL-1-specific probes, although the culture supernatants did not contain detectable TNF/LT biologic activity. When tested in the fetal rat long bone assay, MM plasma cell supernatants displayed a strong osteoclast-activating factor (OAF) activity, which was greatly reduced but not completely abolished by neutralizing anti- IL-1 antibodies. Anti-TNF or anti-LT antibodies were ineffective in the same test. We conclude that the IL-1 released in vivo by malignant plasma cells has a major role in pathogenesis of lytic bone lesions of human MM.

Production of Interleukin-1 by Bone Marrow Myeloma Cells

AbstractPlasma cells isolated from bone marrow (BM) aspirates of 12 patients with multiple myeloma (MM) and nine patients with monoclonal gammopathy of undetermined significance (MGUS) were analyzed for production of cytokines with bone-resorbing activity, such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and lymphotoxin (LT). Culture supernatants of plasma cells from MM, but not from MGUS or normal donor, invariably contained high amounts of IL-1-β and lower amounts of IL-1-α. With a single exception, TNF/LT biologic activity was not detected in the same supernatants. IL-6 was present in two of five supernatants tested. Normal B lymphocytes released both IL-1 and TNF/LT activities for four days after activation in vitro; however, production of these cytokines ceased at the final stage of plasma cell. Unexpectedly, the mRNA extracted from MM plasma cells hybridized with TNF- and LT- specific, as well as IL-1-specific probes, although the culture supernatants did not contain detectable TNF/LT biologic activity. When tested in the fetal rat long bone assay, MM plasma cell supernatants displayed a strong osteoclast-activating factor (OAF) activity, which was greatly reduced but not completely abolished by neutralizing anti-IL-1 antibodies. Anti-TNF or anti-LT antibodies were ineffective in the same test. We conclude that the IL-1 released in vivo by malignant plasma cells has a major role in pathogenesis of lytic bone lesions of human MM.

Ex vivo Treatment of Myeloma Cells by 4-Hydroperoxycyclophosphamide and VP-16–213

To assess the usefulness of 4-hydroperoxycyclophosphamide (4-HC) and VP-16-213 (VP-16) as a purging agent for myeloma cells in bone marrow (BM) ex vivo, myeloma cell lines (SK-RCS-1, RPMI-8226), lymphoma cell line (SK-DHL-2) and normal BM cells were treated at different concentrations of 4-HC or VP-16. Clonogenic tumor cells from all three cell lines could be reduced by more than 4 logs, when treated alone or as a mixture with irradiated normal BM cells at a 4-HC concentration of 60 microM. Under similar conditions, approximately 1% of the normal BM myeloid progenitor granulocyte-macrophage colony-forming cells survived. These observations support the use of 4-HC for purging myeloma cells for autologous BM transplantation.

Establishment of two new myeloma cell lines from bilateral pleural effusions: evidence for sequential in vivo clonal change

Two new human myeloma cell lines have been established from a 36-year- old woman with refractory IgG kappa multiple myeloma in whom bilateral malignant pleural effusions developed. The malignant plasma cells from each effusion were set up in a liquid culture using an L-15 medium containing catalase, glutathione, selenous acid, ascorbic acid, insulin, transferrin, additional glutamine hydrocortisone, and 2- mercaptoethanol and designated as M-3 medium. Two IgG kappa cell lines, LB -831 and LB-832, were established and proved to be Epstein-Barr virus negative using the internal repeat sequence DNA probe. Characteristic plasma cell morphology was evident by light and electron microscopy. Immunotyping revealed an IgG kappa , B1+, B2-, Ia (HLA- DR)+, CALLA+ phenotype for each cell line as well as for the original pleural fluid and bone marrow myeloma cells. The supernatants also contained IgG kappa, beta 2 microglobulin, and large amounts of osteoclast-activating factor (indicating bone-resorbing activity). Cytogenetic analysis of the LB-831 cell line revealed a nearly triploid highly abnormal karyotype with numerous clonal chromosomal abnormalities involving chromosomes 1, 3, 5, 7, 13, and 15; several structurally abnormal marker chromosomes; and a putative homogeneously staining region on chromosome 7p at band p22. Analysis of the LB-832 cell line revealed several additional clonal abnormalities. These additional cytogenetic changes suggest that in vivo sequential clonal evolution occurred in this patient. Therefore, two new but related cell lines have been established, which should prove useful for further biological studies.

Establishment of Two New Myeloma Cell Lines From Bilateral Pleural Effusions: Evidence for Sequential In Vivo Clonal Change

AbstractTwo new human myeloma cell lines have been established from a 36-year-old woman with refractory IgGκ multiple myeloma in whom bilateral malignant pleural effusions developed. The malignant plasma cells from each effusion were set up in a liquid culture using an L-15 medium containing catalase, glutathione, selenous acid, ascorbic acid, insulin, transferrin, additional glutamine hydrocortisone, and 2-mercaptoethanol and designated as M-3 medium. Two IgGκ cell lines, LB-831 and LB-832, were established and proved to be Epstein-Barr virus negative using the internal repeat sequence DNA probe. Characteristic plasma cell morphology was evident by light and electron microscopy. Immunotyping revealed an IgGκ, B1 +, B2–, Ia (HLA–DR) +, CALLA + phenotype for each cell line as well as for the original pleural fluid and bone marrow myeloma cells. The supernatants also contained IgGκ, β2 microglobulin, and large amounts of osteoclast-activating factor (indicating bone-resorbing activity). Cytogenetic analysis of the LB-831 cell line revealed a nearly triploid highly abnormal karyotype with numerous clonal chromosomal abnormalities involving chromosomes 1, 3, 5, 7, 13, and 15; several structurally abnormal marker chromosomes; and a putative homogeneously staining region on chromosome 7p at band p22. Analysis of the LB-832 cell line revealed several additional clonal abnormalities. These additional cytogenetic changes suggest that in vivo sequential clonal evolution occurred in this patient. Therefore, two new but related cell lines have been established, which should prove useful for further biological studies.

Strong natural killer (NK) cell activity in bone marrow of myeloma patients: accelerated maturation of bone marrow NK cells and their interaction with other bone marrow cells.

Bone marrow natural killer (NK) cell activity was studied in patients with multiple myeloma. Bone marrow mononuclear cells from myeloma patients expressed considerable levels of cytotoxicity against K562 in a 4 h 51Cr-release assay, which was comparable to that of blood lymphocytes. In contrast, NK-cell activity was markedly low or absent in bone marrow of normal donors and control patients. Fractionation of bone marrow cells from myeloma patients on linear bovine serum albumin gradients enriched NK effector cells in the upper, lymphocyte-enriched fraction, with no reactivity in the middle fraction containing mainly myeloma cells. Treatment with either Leu-7 or OKMI monoclonal antibody plus complement reduced or abrogated bone marrow NK-cell activity of myeloma patients as well as blood NK-cell activity. However, OKMI plus complement failed to reduce control bone marrow NK-cell activity, although the activity was reduced by Leu-7 plus complement. Overnight exposure to interferon (IFN) of bone marrow cells resulted in an augmentation of NK-cell activity in myeloma patients, but not in controls. Furthermore, adherent bone marrow cells from controls suppressed IFN-induced enhancement of NK-cell activity of blood lymphocytes, whereas bone marrow of myeloma patients did not contain such suppressor cells. No cytotoxicity was induced in control bone marrow cells by cocultivation with bone marrow myeloma cells. Bone marrow NK cells from myeloma patients were able to lyse control bone marrow cells in a 18 h assay and their lytic activity was augmented by IFN treatment. However, neither bone marrow cells nor blood lymphocytes were cytotoxic to autologous and allogeneic fresh myeloma cells even after activation with IFN. These results suggest that NK precursor cells differentiate into HNK-I- and OKMI-positive mature NK cells in bone marrow of myeloma patients, but not in control bone marrow, and that these functional bone marrow NK cells may interact with other bone marrow elements.

Kinetics of circulating B lymphocytes in human myeloma

The tritiated thymidine labeling index (LI%) of peripheral B lymphocytes was studied in eight myeloma patients using simultaneous immunofluorescence and autoradiography. The LI% values were low (0.3%- 5.1%), but significantly increased as compared to normal controls. In addition, there was excellent correlation between the LI% values and myeloma disease activity: lowest LI% values were observed in remission patients and the highest at the time of relapse. Simultaneous LI% evaluation of bone marrow myeloma cells in five patients gave concordant results, indicating the same kinetic behavior in both these compartments, particularly in the relapse phase. These data indicate both that circulating B lymphocytes include the neoplastic clone and that these B lymphocytes and bone marrow myeloma cells have similar kinetics.

Kinetics of Circulating B Lymphocytes in Human Myeloma

The tritiated thymidine labeling index (LI%) of peripheral B lymphocytes was studied in eight myeloma patients using simultaneous immunofluorescence and autoradiography. The LI% values were low (0.3%-5.1%), but significantly increased as compared to normal controls. In addition, there was excellent correlation between the LI% values and myeloma disease activity: lowest LI% values were observed in remission patients and the highest at the time of relapse. Simultaneous LI% evaluation of bone marrow myeloma cells in five patients gave concordant results, indicating the same kinetic behavior in both these compartments, particularly in the relapse phase. These data indicate both that circulating B lymphocytes include the neoplastic clone and that these B lymphocytes and bone marrow myeloma cells have similar kinetics.

IgD-Plasma Cell Leukemia Associated with Pyroglobulinemia and Pyroglobulinuria

New pyroglobulin variants were found in a patient with a typical plasma cell leukemia. One was found in the urine and proved to be a variant of Bence-Jones' protein with a molecular weight of approximately 68,000. The other was found in the serum and appears to be the myeloma protein of IgD. Furthermore, an ultrastructural study disclosed myeloma cells in both peripheral blood and bone marrow to have cytoplasmic fibrils which might be unique for plasma cell leukemia.

Relation of osteoclast activating factor production to extent of bone disease in multiple myeloma.

Measurements of total body myeloma cell number and osteoclast activating factor (OAF) production by bone marrow myeloma cells in vitro were made in 33 patients with plasma cell myeloma. There was a highly significant correlation (P < 0.001) between the amount of OAF produced by bone marrow myeloma cells and the extent of skeletal destruction. Serial studies indicated reduction of OAF production with remission induction and high OAF production at the time of relapse with new bone destruction. Although hypercalcaemia occurred only in patients with the most extensive bone lesions, there was no direct relationship between OAF production and the serum calcium concentration. These data suggest that measurement of OAF production in multiple myeloma may predict those patients at risk for development of extensive skeletal destruction due to this neoplasm.

REAPPRAISAL OF PLATEAU PHASE IN MYELOMA

The frequency with which the plateau or stable phase occurs after remission-induction chemotherapy, and the kinetic features of this phase, were evaluated in 127 carefully staged patients with multiple myeloma. 56 patients (44%) entered a stable plateau state, this pattern being most common in patients with stages IA, IIA, and IIIA of the disease, and least likely in those with stages IIB or IIIB, especially those with Bence Jones protein only or Bence Jones protein plus a serum M-component. Tritiated thymidine labelling index (LI) of bone-marrow myeloma cells, polyamine measurements, and in-vitro myeloma stemcell culture findings all indicated that the plateau phase is a cytokinetically quiescent state, compared with the more active induction and relapse phases. The major implications of these findings include the avoidance of aggressive "cycle active" treatment and discontinuation of maintenance treatment in plateau-phase patients.

G-banding analysis of complex aneuploidy in multiple myeloma bone marrow cells

Chromosome studies with the banding technique have been performed in a considerable number of cases of myeloproliferative diseases, but technical difficulties have so far prevented detailed studies of chromosomal abnormalities in multiple myeloma. The karyotypes of bone marrow cells from two patients with multiple myeloma have been analyzed by a trypsin-Giemsa banding technique. Evidence is given for clonal evolution which in one patient has probably occurred by cell fusion and subsequent chromosome loss. Eight different marker chromosomes are characterized. Nonrandom chromosomal participation in the translocations and the existence of specific vulnerable points on chromosomes 1, 3, and 16 are suggested.

G-Banding Analysis of Complex Aneuploidy in Multiple Myeloma Bone Marrow Cells

Abstract Chromosome studies with the banding technique have been performed in a considerable number of cases of myeloproliferative diseases, but technical difficulties have so far prevented detailed studies of chromosomal abnormalities in multiple myeloma. The karyotypes of bone marrow cells from two patients with multiple myeloma have been analyzed by a trypsin-Giemsa banding technique. Evidence is given for clonal evolution which in one patient has probably occurred by cell fusion and subsequent chromosome loss. Eight different marker chromosomes are characterized. Nonrandom chromosomal participation in the translocations and the existence of specific vulnerable points on chromosomes 1, 3, and 16 are suggested.