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)

The presence of primitive hematopoietic progenitor cells or stem cells in peripheral blood (PBSC's) harvests was investigated in a single cell culturing assay and compared with the results obtained in aspirates of normal bone marrow. Based on the presence of CD33, rather differentiated progenitor cells (CD34+/33+) were distinguished from more primitive cells (CD34+/33-). The growth potential of CD34+/33+ and CD34+/33- cells have been studied. Single cell sorting was performed from peripheral blood harvests, obtained from three patients with multiple myeloma during hematopoietic recovery after treatment with high dose cyclophosphamide and rhu-GM-CSF. To test the effect of "stem cell recruiting factors" the cells were sorted in 96-well plates, prefilled with liquid medium both in the presence of IL-3 + G-CSF+GM-CSF+Epo and the same growth factors supplemented with SCF+IL-6. Addition of SCF and IL-6 to the culturing medium enhanced the plating efficiency of CD34+/33- cells considerably more than that of CD34+/33+ cells. This was observed in harvests of peripheral blood as well as in aspirates of normal bone marrow. The differences between CD34+/33+ and CD34+/33- were even more pronounced when only the large colonies (> 500 cells/well) were taken into consideration. Assuming that IL-6 and SCF are "stem cell recruiting factors," the CD34+/33- fraction contains more clonogenic cells than the CD34+/33+ fraction. In all three patients the first CD34+ cells appearing in the peripheral blood (PB) after cytoreductive treatment were predominantly CD34+/33- (> 80%). At later stages when the leukocyte counts had reached higher values the CD34+/33+ cells predominated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Peripheral blood cell harvests yield primitive multilineage progenitor cells in the CD34+/33- fraction. 751 21

The change in phenotype, number and proliferative capacity of peripheral blood hematopoietic progenitors (PBHP) was studied in six patients with multiple myeloma during hematopoietic recovery after mobilization with high-dose cyclophosphamide and GM-CSF or G-CSF. In all six patients the first CD34+ cells appearing in the peripheral blood (PB) after cytoreductive treatment were predominantly CD34+/33- (> 70%). At later stages when leukapheresis procedures were started, the CD34+/33+ cells predominated in five of six patients. In leukapheresis harvests of peripheral blood, and in bone marrow addition of SCF and IL-6 to the culturing medium enhanced the plating efficiency. In peripheral blood an increase from 12 to 22% for CD34+/33+ and from 6 to 14% for CD34+/33- was observed. In normal bone marrow we observed an increase from 15 to 23% for CD34+/33+ and from 7 to 17% for CD34+/33-. Highly proliferative progenitors (>500 cells) in the CD34+/33- fraction appeared to be dependent on the addition of 'stem cell recruiting factors' (SCF and IL-6); in bone marrow the percentage of wells with >500 cells increased from 0.9 to 12.6% after SCF+IL-6 and in PBHP from 2 to 9%. We conclude that the first progenitors appearing in the peripheral blood after priming with high-dose cyclophosphamide and GM- or G-CSF have a more primitive immunophenotype, CD34+/33-.
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PMID:Primitive multilineage progenitor cells predominate in peripheral blood early after mobilization with high-dose cyclophosphamide and GM-CSF or G-CSF. 752 61

In this study we investigated the proliferation of three well-documented MM lines and 10 bone marrow samples from myeloma patients in response to rh-SCF alone and combined with Interleukin-6 (IL-6), IL-3 and IL-3/GM-CSF fusion protein PIXY 321. Neoplastic plasma cells were highly purified (> 90%) by immunomagnetic depletion of T, myeloid, monocytoid and NK cells. The number of S-phase cells was evaluated after 3 and 7 d of liquid culture by the bromodeoxyuridine (BRDU) incorporation assay. The proliferation of RPMI 8226 and U266 cell lines was also assessed by a clonogenic assay. All the experiments were performed in serum-free conditions. RPMI 8226 cell line was not stimulated by SCF which also did not augment the proliferative activity of IL-6, IL-3 and PIXY-321. Conversely, SCF addition resulted in 2.4-fold increase of the number of U266 colonies and in a higher number of U266 and MT3 cells in S-phase (24.5 +/- 2% SEM v 14.5 +/- 1% SEM and 32 +/- 3% SEM v 21 +/- 4% SEM, respectively; P < 0.05). The c-kit ligand also enhanced the proliferation of MT3 and U266 cells mediated by the other cytokines. Anti-SCF polyclonal antibodies completely abrogated the proliferative response of MT3 cells to exogenous SCF and markedly reduced the spontaneous growth of the same cell line. Reverse transcriptase-polymerase chain reaction amplification (RT-PCR) did detect SCF mRNA in MT3 and RPMI 8226 cells. Moreover, secreted SCF was found, in a biologically active form, in the supernatant of the two cell lines by the MO7e proliferation assay. When tested on fresh myeloma samples, SCF increased the number of S-phase plasma cells (4.7 +/- 1.6% v 3.4 +/- 1.3% in control cultures: P = 0.02). Significant proliferation was also induced by IL-6 (7 +/- 2.3% of BRDU+ cells; P = 0.006), IL-3 (5.3 +/- 1.3%; P = 0.01) and PIXY-321 (5.4 +/- 1.6%; P = 0.02). The addition of SCF significantly enhanced the proliferation of myeloma cells responsive to IL-6. In summary, our results indicate that SCF is expressed in MM cells and stimulates the proliferation of neoplastic plasma cells.
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PMID:Expression and functional role of c-kit ligand (SCF) in human multiple myeloma cells. 752 40

We have studied retroviral-mediated gene transfer into human myeloma cells. Bone marrow cells were obtained from four patients with advanced myeloma, where the marrow was heavily infiltrated with myelomatous plasma cells. Myeloma cells were isolated by immunomagnetic separation, using the high-affinity B-B4 monoclonal antibody. Following separation, cells were transduced with the LN retroviral vector, which carries the gene for neomycin phosphotransferase, by incubation in cell-free supernatant with or without a growth-factor combination of IL-3, IL-6 and SCF. After infection, the cells were cultured for 9 d in RPMI-1640 and 10% FCS, either in the presence or absence of the neomycin analogue G418. Transduction efficiency was 1.5-3.8%, when compared to the number of cells at initiation of the culture, and 5.0-50.0% when compared to the number of surviving infected cells cultured without G418. The gene transfer rate was similar whether or not growth factors were present during the retroviral infection. These preclinical data provide evidence that retroviral-mediated gene transfer into human myeloma cells is feasible, and form part of the basis for current clinical studies of gene marking of bone marrow or peripheral blood progenitor cells before autologous stem cell transplantation in multiple myeloma.
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PMID:Retroviral-mediated gene transfer into human myeloma cells. 780 77

The survival, proliferation, differentiation and function of normal hematopoietic cells are negatively and positively controlled by various cytokines. Survival and proliferation of leukemic cells appears to be influenced, at least in vitro, by several cytokines. Among the different hematopoietic cell lineages, megakaryocytopoiesis represents a complex and unique hematopoietic system that is thought to be supported by some well-known cytokines; however, the hypothetical lineage-specific main regulator of platelet production, termed thrombopoietin (TPO) had remained elusive. Recently, characterization of the proto-oncogene c-mpl revealed structural homology with the hematopoietic cytokine receptor superfamily, specific expression on cells of the megakaryocytic lineage and functional involvement in megakaryocytopoiesis. Several groups purified and cloned the MPL ligand. Extensive in vitro and in vivo studies have shown that the MPL ligand has activity in stimulating both megakaryocytopoiesis and platelet production proving that this ligand is the long-sought growth factor TPO itself. The MPL receptor was found at the mRNA and/or protein level in 40-80% of primary acute myeloid leukemia (AML) cases in various series. MPL expression was not limited to certain morphological FAB types, although the highest percentages were seen in the M6 (erythroid) and M7 (megakaryocytic) subclasses. Among the myelodysplastic syndromes (MDS), MPL expression was detected in one third of the cases, in particular in refractory anemia with excess of blasts and chronic myelomonocytic leukemia. Lymphoid malignancies such as acute lymphoblastic leukemia (ALL), non-Hodgkin's lymphoma (NHL) and myeloma were MPL-negative. Among the large panel of human leukemia-lymphoma cell lines studied, MPL expression occurred predominantly in lines with erythro-megakaryocytic phenotypes. Nearly all primary and continuously cultured non-hematopoietic solid tumor samples were negative for MPL expression. A significant portion of AML cases and of erythroid, megakaryocytic and myeloid leukemia cell lines co-expressed TPO and MPL mRNA transcripts, although no biologically active TPO appeared to be secreted by these cells. In several studies TPO induced in vitro proliferation of 14-37% of primary AML cases, predominantly of the M2 and M7 subtypes. TPO significantly enhanced the cytokine-induced growth of AML cells in a substantial fraction of cases responsive to GM-CSF, IL-3, IL-6 or SCF. While none of 30 growth factor-independent erythro-megakaryocytic leukemia cell lines responded to TPO with increased proliferation, TPO strongly augmented the growth of several constitutively cytokine-dependent cell lines (eg HU-3, M-07e, TF-1) which can be made TPO-dependent and used as bioassays. Neither in primary cells nor in cell lines did TPO appear to induce any signs of morphological, functional or immunological differentiation. Expression of the MPL receptor is not correlated with a proliferative response to TPO. In summary, extensive studies on normal human and animal cells demonstrated the specificity and function of the MPL receptor and proved that its ligand TPO is the major physiological regulator of megakaryocytopoiesis. The data reviewed here document the wide expression of the MPL receptor on AML cells and also suggest some proliferative effects on certain leukemia cells, apparently on non-megakaryocytic AML cells as well. Thus, experimental evidence supports the notion that TPO may contribute, at least in part, to leukemogenesis, especially in combination with other hematopoietic cytokines which is of clinical significance. TPO-responsive cell lines represent powerful tools for such analyses.
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PMID:Thrombopoietin: expression of its receptor MPL and proliferative effects on leukemic cells. 875 57

Here we review our recent experience addressing the role of SCF in multiple myeloma (MM). We first investigated the proliferation of MM cell lines and bone marrow samples from myeloma patients in response to rh-SCF alone and combined with Interleukin-6 (IL-6), IL-3, and IL-3/GM-CSF fusion protein PIXY 321. Neoplastic plasma cells were highly purified (>90%) by immunomagnetic depletion of T, myeloid, monocytoid and NK cells. The number of S-phase cells was evaluated after 3 days of liquid culture by the bromodeoxyuridine (BRDU) incorporation assay. The proliferation of RPMI 8226 and U266 cell lines was also assessed by a clonogenic assay. All the experiments were performed in serum-free conditions. RPMI 8226 cell line was not stimulated by SCF which also did not augment the proliferative activity of IL-6, IL-3 and PIXY-321. Conversely, SCF addition resulted in 2.4-fold increase of the number of U266 colonies and in a higher number of U266 and MT3 cells in S-phase. The c-kit ligand also enhanced the proliferation of MT3 and U266 cells mediated by the other cytokines. Anti-SCF polyclonal antibodies completely abrogated the proliferative response of MT3 cells to exogenous SCF and markedly reduced the spontaneous growth of the same cell line. Reverse transcriptase-polymerase chain reaction amplification (RT-PCR) did detect SCF mRNA in MT3 and RPMI 8226 cells. Moreover, secreted SCF was found, in a biologically active form, in the supernatant of the two cell lines by the MO7e proliferation assay. These results suggest that an autocrine proliferative loop may be operative in MT3 cell line. When tested on fresh myeloma samples, SCF increased the number of S-phase plasma cells (4.7 +/- 1.6% vs 3.4 +/- 1.3% in control cultures; p = 0.02). Significant proliferation was also induced by IL6, IL-3 and PIXY-321. The addition of SCF significantly enhanced the proliferation of myeloma cells responsive to IL-6. Preliminary experiments performed on circulating plasma cells and myeloma precursors further supported the role of SCF on the proliferation of the neoplastic clone in MM.
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PMID:C-kit ligand (SCF) in human multiple myeloma cells. 883 3

In this article, we review neoplastic contamination in the peripheral blood (PB) of patients with multiple myeloma (MM) upon stem cell mobilization. We first evaluated PB samples from pretreated MM patients following administration of high-dose cyclophosphamide (Cy, 7 g/m2 or 4 g/m2) and granulocyte colony-stimulating factor (G-CSF) for the presence of myeloma cells as well as hematopoietic progenitors. Plasma cells containing intracytoplasmic immunoglobulin (cIg) were counted by immunofluorescence microscopy after incubation with appropriate antisera against light and heavy chain Ig. Flow cytometry studies were performed to determine the presence of malignant B lineage elements, using monoclonal antibodies against the CD19 antigen and the monotypic light chain. Prior to PBSC mobilization, circulating plasma cells were detected in all MM patients at 0.1%-1.8% of the mononuclear cell (MNC) fraction (mean value 0.7 +/- 0.4% SD). In these patients, a higher absolute number of PB neoplastic cells was detected after administration of chemotherapy and G-CSF. Kinetic analysis showed a pattern of tumor cell mobilization similar to that of normal hematopoietic progenitors, with the peak coinciding with the optimal period for the collection of PBSC. The absolute number of plasma cells showed a 10-50-fold increase over the baseline value. Apheresis products contained 0.7 +/- 0.2% SD myeloma cells (range 0.2%-2.7%), which demonstrated the capacity of plasma cells to proliferate, differentiate, and mature in response to c-kit ligand (SCF), IL-3, IL-6, and a combination of IL-3 and IL-6. Subsequently, in an attempt to reduce tumor cell contamination prior to autologous transplantation, circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, cryopreserved, and used to reconstitute bone marrow (BM) function after myeloablative therapy in 13 patients. The median purity of the enriched CD34+ cell population was 89.5% (range 51%-94%), with a 75-fold enrichment compared with the pretreatment samples. The median overall recovery of CD34+ cells and CFU-GM was 58% (range 33%-95%) and 45% (range 7%-100%), respectively. Positive selection of CD34+ cells resulted in 2.5-3 log depletion of plasma cells and CD 19+ B lineage cells as determined by immunofluorescence studies, although DNA analysis of the CDR III region of the IgH gene demonstrated the persistence of minimal residual disease (MRD) in 5 of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (TBI, 1000 cGy) and high-dose melphalan (140 mg/m2) or melphalan (200 mg/m2) alone. They received a median of 5 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis. The median time to 0.5 x 10(9) neutrophils, 20 x 10(9) and 50 x 10(9) platelets/L of PB was 10, 11, and 12 days, respectively. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (n = 13) receiving unmanipulated PBSC following the same pretransplant conditioning regimen. Our data demonstrate the concomitant mobilization of tumor cells and hematopoietic progenitors in the PB of MM patients. Positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3 log and provides a cell suspension capable of restoring normal hematopoiesis following a TBI-containing conditioning regimen.
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PMID:Concomitant mobilization of plasma cells and hematopoietic progenitors into peripheral blood of patients with multiple myeloma. 887 9

We studied the feasibility of in vitro expansion of CD34+ cells from patients with multiple myeloma (MM) or follicular non Hodgkin lymphoma (NHL). CD34+ cells were selected from peripheral blood (PB) using avidinbiotin immunoadsorption columns: purified CD34+ cells from three MM and five NHL patients were expanded. First, CD34+ cells (2 MM, 4 NHL) were grown for 14 days in 5 ml of IMDM plus 12.5% horse serum (HS), 12.5% fetal calf serum (FCS) and a commonly used combination of cytokines: IL1alpha, IL3, IL6, SCF, GM-CSF, G-CSF (10 ng/ml each) and EP (4 UI/ml). In these conditions, at day 14, average increase in CD34+, CFU-GM and total cell numbers were, respectively: x 6.0 x 23 and x 2,113 fold with 20 to 35% of granulocytic cells. In terms of CD34+ cell, CFU-GM and total cell outputs, MM cultures were comparable to NHL cultures, but MM cultures seemed to produce less granulocytic cells than NHL cultures. Next, in vitro expansion of PB CD34+ cells was tested in culture media suitable for clinical use. Two cultures (1 MM, 1 NHL) were carried out for 14 days in 20 ml of X-Vivo 10 medium, 2% human serum, IL1alpha, IL3, IL6, SCF, GM-CSF, G-CSF (6 ng/ml each) and EP (2 UI/ml). Increase in CD34+, CFU-GM and total cell numbers in these conditions were, respectively: x 5.7 and x 19.7, x 11.9 and x 40.9, x 424 and x 408 fold, with at least 75% of granulocytic cells in both cultures. We conclude that, although further improvements are necessary, in vitro expansion of PB CD34+ cells can presumably be carried out successfully for MM patients as well as for NHL patients, including in conditions suitable for clinical use.
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PMID:In vitro expansion of CD34+ cells from peripheral blood of myeloma and lymphoma patients. 890 29

Mobilized CD34+ blood cells were immunomagnetically enriched from leukapheresis products in five multiple myeloma (MM) patients. Thawed samples of selected CD34+ cells were cultured for up to 21 d in a liquid and stroma-free culture system with different combinations of recombinant cytokines. The most successful cell expansion was obtained when a combination of rh-IL-1beta, rh-IL-3, rh-IL-6, rh-SCF, rh-G-CSF and rh-GM-CSF was used. After 14 d this mixture gave a 120-187-fold overall increase of total nuclear cells and a 4-8-fold overall increase of early CFU-GM numbers. In four patients a very sensitive patient-specific PCR analysis showed the presence of monoclonal cells in the initial leukapheresis products. After immunomagnetic separation a tumour cell depletion of 2-4 logs was observed, although all samples still contained malignant cells. Cell suspensions that were cultured with the most potent cytokine combination showed tumour contamination in two-thirds of evaluable cases at the moment of maximal CFU-GM output. Serial cDNA dilution experiments indicated that the positive PCR results at day 14 reflected the persistence of pre-culture tumour cells rather than in vitro expansion of tumour cells in two cases. This study demonstrates that ex vivo expansion of myeloid precursor cells from mobilized CD34+ cells in MM patients does not always result in an effective purging of residual tumour cells. On the other hand, our culture conditions do not seem to favour in vitro expansion of malignant cells, despite the use of a cytokine cocktail that includes potential myeloma growth factors.
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PMID:Persistence of residual tumour cells after cytokine-mediated ex vivo expansion of mobilized CD34+ blood cells in multiple myeloma. 902 33

The feasibility of ex vivo expansion of hematopoietic progenitors selected from leukapheresis products of patients treated for multiple myeloma (MM) was studied and compared with progenitor expansions from patients with nodular non-Hodgkin's lymphoma (NHL) or healthy donors. After positive selection, CD34+ cells from leukapheresis products of 4 MM and 5 NHL patients and CD34+ cells from bone marrow (BM) of 3 healthy donors were grown in IMDM plus 12.5% horse serum, 12.5% fetal calf serum, IL-1alpha, IL-3, IL-6, SCF, GM-CSF, G-CSF (10 ng/ml each), and EP (4 UI/ml). Outputs of CD34+ cell cultures from MM and NHL patients were similar. Day 14 mean increases in CD34+, CFU-GM, and total cell numbers were, respectively, 5.3-fold, 19.8-fold, and 1173-fold for MM patients and 4.3-fold, 15.6-fold, and 1659-fold for NHL patients, with at least 40% of day 14 cells being of granulocytic lineage. Patient CD34+ cell culture output was found to be related to the CFU-GM/CD34+ cell ratio of selected CD34+ cells, not to underlying pathology. When the initial CFU-GM/CD34+ cell ratio was above 0.025, MM and NHL CD34+ cell culture outputs were always above 1000-fold. Moreover, in all but one CD34+ cell culture, the use of fibronectin (FN)-coated dishes improved CFU-GM and total cell expansion. In patient CD34+ cultures carried out in FN-coated dishes, mean day 14 CFU-GM and total cell outputs were increased, respectively, 2.1-fold and 1.9-fold. We conclude that if the CFU-GM/CD34+ cell ratio is sufficient (>0.025), ex vivo expansion of hematopoietic progenitors from CD34+ cells selected from leukapheresis products is possible for both MM and NHL patients and that using FN-coated flasks is a simple and reliable way to improve both CFU-GM and total cell output.
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PMID:Ex vivo expansion of hematopoietic progenitors from CD34+ cells selected from leukapheresis products of lymphoma and myeloma patients: feasibility and enhancement by fibronectin. 911 56

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