Myeloma Phenotype: Clues To Disease Origin and Manifestation

Sensitization of multiple myeloma and B lymphoma lines to dexamethasone and ?-radiation-induced apoptosis by CD40 activation

We examined the effects of CD40 activation with dexamethasone (Dex) or 60Co-gamma-irradiation on the growth of malignant B cells in vitro, using the human multiple myeloma (MM) cell line, XG2, and the B lymphoma Daudi cell line as models. Both lines are resistant to Dex and irradiation; 10(-7)M Dex or 10 Gy of gamma-irradiation induced only minimal growth arrest and apoptosis of the cells. Treatment of the cells with the agonistic anti-CD40 monoclonal antibody 5C11 partially inhibited the proliferation of the Daudi cells; XG2 underwent apoptosis. XG2 is an Interleukin-6 (IL-6)-dependent myeloma cell line and CD40 activation blocked XG2 in the G1 phase of the cell cycle, in a manner similar to the effect of IL-6 deprivation. Daudi was blocked in the G2/M phase after treatment with the agonistic CD40 mAb 5C11. Furthermore, the activation of CD40 on Daudi and XG2 enhanced their sensitivity to dexamethasone-and gamma-irradiation -induced growth arrest and apoptosis. CD40 activation stimulated both anti-apoptotic Bcl-XL and pro-apoptotic Bax mRNA synthesis in the Daudi cell line; CD40 activation increased the Bax mRNA level but had no effect on the Bcl-XL mRNA level in the XG2 cell line. Apoptosis in both cell lines was associated with an increasing ratio of Bax-to-Bcl-XL both in mRNA and in protein levels. It is concluded that use of the anti-CD40 mAb 5C11 either by itself or in combination with chemotherapy and/or radiotherapy may have significant therapeutic potential.

MIP-1 alpha and myeloma bone disease

Figure 5 is a proposed model for MIP-1alpha's effects on myeloma bone disease. MIP-1alpha is produced by myeloma cells and directly stimulates OCL formation. In addition MIP-1alpha enhances adhesive interactions between myeloma cells and marrow stromal cells increasing expression of RANKL and IL-6, which further increase bone destruction and tumor burden. The recent evidence from our group and others lead to the conclusion that MIP-1alpha is an important mediator in the debilitating bone destruction in multiple myeloma. Blocking MIP-1alpha expression may have profound effects on myeloma cell growth, homing, and bone destruction in this in vivo model of myeloma. These data suggest that antagonists that decrease MIP-1alpha activity in vivo or blocking MIP-1alpha signaling by neutralizing its receptor may provide therapeutic alternatives for treating patients with myeloma to decrease both their tumor burden and bone destruction.

Biology of osteoclast activation in cancer

Bone is a frequent site of cancer metastasis. Bone metastases can result in bone destruction or new bone formation. Bone destruction is mediated by factors produced or induced by tumor cells that stimulate formation and activation of osteoclasts, the normal bone-resorbing cells. Local bone destruction also occurs in patients with osteoblastic metastases and may precede or occur simultaneously with increased bone formation. Several factors, including interleukin (IL)-1, IL-6, receptor activator of NF-kappaB (RANK) ligand, parathyroid hormone-related protein (PTHrP), and macrophage inflammatory protein-1-alpha (MIP-1alpha), have been implicated as factors that enhance osteoclast formation and bone destruction in patients with neoplasia. PTHrP seems to be the major factor produced by breast cancer cells that induces osteoclast formation through upregulation of RANK ligand. Enhanced RANK ligand expression also plays an important role in bone destruction in patients with myeloma. RANK ligand can act to enhance the effects of other factors produced by myeloma cells or in response to myeloma cells, such as MIP-1alpha and/or IL-6, to induce osteoclast formation. Understanding of the molecular mechanisms responsible for osteoclast activation in osteolytic metastases should lead to development of novel therapeutic approaches for this highly morbid and potentially fatal complication of cancer.

Myeloma bone disease

Bone destruction is a hallmark of myeloma, with 70% to 80% of patients manifesting bone involvement. Destruction is mediated through normal osteoclasts (OCLs), which respond to local osteoclast-activating factors (OAFs) produced by myeloma cells or by other cells in the local microenvironment. OAFs implicated in myeloma bone disease include tumor necrosis factor-beta (TNFbeta), RANK ligand (RANKL), interleukin-1 (IL-1), parathyroid hormone-related protein (PTHrP), hepatocyte growth factor (HGH), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFalpha), and macrophage inflammatory protein-1-alpha (MIP-1alpha). To date, the leading candidates for OAFs are MIP-1alpha and RANKL. Adhesive interactions between marrow stromal cells and myeloma cells induce marrow stromal cells to secrete IL-6, a potent myeloma growth/survival factor that may contribute to the bone disease. Evaluation of myeloma bone disease includes plain radiographs, and newer methods, such as magnetic resonance imaging (MRI), positron emission tomography (PET) scans, technetium-99m-sestamibi (Mibi) scanning, and dual-energy x-ray absorptiometry (DEXA) scanning, may provide more complete information. In addition, biochemical markers of bone resorption are being evaluated, although the limited availability of these assays and lack of extensive testing in patients make their routine use premature. Treatment of myeloma bone disease includes radiation therapy, vertebroplasty, surgery, and bisphosphonates. New developments on the pathogenesis and treatment of myeloma bone disease present great opportunities to combat bone disease.

Acute lymphoblastic leukaemia-type intensive chemotherapy to eliminate minimal residual disease after high-dose melphalan and autologous transplantation in multiple myeloma - a phase I/II feasibility and tolerance study of 17 patients

Aiming to target the minimal residual disease in patients with multiple myeloma, a phase I/II single centre study was undertaken for feasibility and tolerance of intensive acute lymphoblastic leukaemia consolidation chemotherapy (ALL-IC) as part of a strategy for post-transplant consolidation targeted at pre-B cells. Seventeen newly diagnosed patients with myeloma (median age 55 years; 30-65) were initially treated with courses of infused cyclophosphamide, vincristine, adriamycin and methylprednisolone (C-VAMP) followed by melphalan 200 mg/m2(HDM) and peripheral blood stem cell rescue (PBSC). Forty-seven percent were in CR and the rest in PR after HDM. ALL-IC consisted of vincristine, daunorubicin, etoposide, cytarabine, 6-thioguanine and prednisolone given over 5 days. All patients became neutropenic (<0.5 x 109/l) at a median of 10 days (4-18) and one of the 17 patients (5.8%) died 15 days post ALL-IC of sepsis. A further four have died of relapse with an overall survival (OS) of 67% at 4 years. Two of nine patients in PR at the time of ALL-IC achieved CR. Matched-pair analysis of 34 control patients shows no difference for OS and event-free survival between ALL-IC and controls. We conclude that ALL-IC given to myeloma patients after HDM/PBSC is as safe as when used in ALL and warrants further assessment in randomised trials for myeloma.

The Proliferative Potential of Myeloma Plasma Cells Manifest in the SCID-hu Host

The low proliferative activity of myeloma plasma cells prompted the notion that the clonotypic B cells that exist in the blood and bone marrow of all myeloma patients contain the proliferative myeloma cells (stem cell). We have exploited our severe combined immunodeficiency (SCID)-hu host system for primary myeloma to investigate whether myeloma plasma cells are capable of sustained proliferation. Purified CD38++CD45− plasma cells consistently grew and produced myeloma and its manifestations in SCID-hu hosts (8 of 9 experiments). In contrast, the plasma cell-depleted bone marrow cells from 6 patients did not grow or produce myeloma in SCID-hu hosts. Similarly, whereas plasma-cell containing blood cells from 4 patients grew and produced myeloma in hosts, neither the PC-depleted blood cells from 3 of the patients nor a blood specimen that did not contain plasma cells grew in SCID-hu hosts, regardless of their CD19-expressing cell contents. Also, in hosts injected with blood cells, although the myeloma cells were able to disseminate through the murine host system, they were only able to grow in the human bones within a human microenvironment and were not detectable in the murine blood or other organs. Interestingly, the circulating plasma cells appear to grow more avidly in the SCID-hu hosts than their bone marrow counterparts, suggesting that they represent a subpopulation of the plasma cells in the bone marrow. Although our studies clearly demonstrate the proliferative potential of myeloma plasma cells, they are suggestive, not conclusive, as to the existence of a preplasmacytic myeloma progenitor cell.

Combined morphological and interphase fluorescence in situ hybridization study in multiple myeloma of Chinese patients

To gain insight into the real incidence of the numeric chromosomal aberrations and the cell lineage involvement of the neoplastic process in multiple myeloma (MM), we examined 18 Chinese MM patients by May-Grunwald-Giemsa (MGG) staining and fluorescence in situ hybridization using three DNA centromeric probes specific for chromosomes 3, 7, and 9. In this investigation, cytogenetic abnormalities were detected in plasma cells (PCs), myeloid cells (MCs), and lymphoid cells (LCs) in all of the MM patients studied. This is the first demonstration of the cytogenetic aberration involved in the myeloid series. Furthermore, the MCs and PCs of 16 MM patients had the same aneuploidies in one or more of the chromosomes analyzed. These data suggest that the neoplastic transformation of MM may occur early in the hematopoietic development. Chromosomal aberrations involving mainly subclones and considerable cellular heterogeneity with gain of a variety of copy numbers of the same chromosome were demonstrated within PCs, which may possibly be the result of an underlying defect of PCs in the control of their number of chromosomes. Whereas PCs showed evidence suggestive of increased polyploidization, MCs and LCs, which exhibited similar chromosomal patterns as the former, rarely did. Thus, the clonal evolution from LC to PC, if that happens in MM, is characterized by chromosomal instability favoring growth of tumor cells with polysomies and polyploidies.

Mutations in the Fas Antigen in Patients With Multiple Myeloma

Programmed cell death, or apoptosis, is well documented as a physiological means of eliminating activated lymphocytes and maintaining immune homeostasis. Apoptosis has also been implicated in the targeting of tumor cells by cytotoxic T lymphocytes and natural killer cells. One of the two primary mechanisms used in cell-mediated cytotoxicity is the Fas/FasLigand system. Activated or transformed cells expressing the Fas antigen on their surface are susceptible to killing by immune effector cells that express the Fas ligand. Many neoplastic cells, including those derived from patients with multiple myeloma, express Fas antigen on their surface, but do not undergo apoptosis in response to antigen crosslinking. One possibility for the lack of Fas-mediated apoptosis includes mutations in the Fas antigen. Loss of function mutations in the Fas antigen have been associated with congenital autoimmune disease in humans, and have been defined as the genetic defect the in lpr mice. Mutations in the Fas antigen have not been previously described in cancer patients. In this study, we show that mutations occur in the Fas antigen which may cause loss of function and contribute to the pathogenesis of the neoplastic disease, multiple myeloma. Using reverse transcriptase-polymerase chain reaction (RT-PCR), single-stranded conformation polymorphism (SSCP) analysis, and DNA sequencing, we examined the cDNA structure of the Fas antigen in 54 bone marrow (BM) specimens obtained from myeloma patients. Six patient specimens (11%) did not express detectable levels of Fas antigen mRNA. Of the 48 BM specimens which did express Fas antigen, 5 (10%) displayed point mutations. All of the mutations identified were located in the cytoplasmic region of the Fas antigen known to be involved in transduction of an apoptotic signal. Two separate individuals demonstrated an identical mutation at a site previously shown to be mutated in the congenital autoimmune syndrome, ALPS. One patient exhibited a point mutation at a site only two amino acids removed from the documented lesion of the lprcg mouse. Although the functional status of these point mutations remains to be determined, we propose that Fas antigen mutations may contribute to the pathogenesis and progression of myeloma in some patients.

Mutations in the Fas Antigen in Patients With Multiple Myeloma

Programmed cell death, or apoptosis, is well documented as a physiological means of eliminating activated lymphocytes and maintaining immune homeostasis. Apoptosis has also been implicated in the targeting of tumor cells by cytotoxic T lymphocytes and natural killer cells. One of the two primary mechanisms used in cell-mediated cytotoxicity is the Fas/FasLigand system. Activated or transformed cells expressing the Fas antigen on their surface are susceptible to killing by immune effector cells that express the Fas ligand. Many neoplastic cells, including those derived from patients with multiple myeloma, express Fas antigen on their surface, but do not undergo apoptosis in response to antigen crosslinking. One possibility for the lack of Fas-mediated apoptosis includes mutations in the Fas antigen. Loss of function mutations in the Fas antigen have been associated with congenital autoimmune disease in humans, and have been defined as the genetic defect the in lpr mice. Mutations in the Fas antigen have not been previously described in cancer patients. In this study, we show that mutations occur in the Fas antigen which may cause loss of function and contribute to the pathogenesis of the neoplastic disease, multiple myeloma. Using reverse transcriptase-polymerase chain reaction (RT-PCR), single-stranded conformation polymorphism (SSCP) analysis, and DNA sequencing, we examined the cDNA structure of the Fas antigen in 54 bone marrow (BM) specimens obtained from myeloma patients. Six patient specimens (11%) did not express detectable levels of Fas antigen mRNA. Of the 48 BM specimens which did express Fas antigen, 5 (10%) displayed point mutations. All of the mutations identified were located in the cytoplasmic region of the Fas antigen known to be involved in transduction of an apoptotic signal. Two separate individuals demonstrated an identical mutation at a site previously shown to be mutated in the congenital autoimmune syndrome, ALPS. One patient exhibited a point mutation at a site only two amino acids removed from the documented lesion of the lprcg mouse. Although the functional status of these point mutations remains to be determined, we propose that Fas antigen mutations may contribute to the pathogenesis and progression of myeloma in some patients.

Tumor necrosis factor-alpha and interleukin 4 in myeloma cell precursor differentiation

Multiple myeloma is a B-cell malignancy characterized by the accumulation of a clonal population of plasma cells in the bone marrow that secrete a monoclonal immunoglobulin protein. It has been regarded as a tumor arising at the B, pre-B lymphocyte, or even stem cell level. Precursor cells are presumed to proliferate and differentiate, giving rise to clonal expansion in plasma cells. Peripheral blood mononuclear cells (PBMC) from 36 patients with multiple myeloma, 12 with monoclonal gammopathy of undetermined significance (MGUS), and 21 healthy controls were cultured in vitro in the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin 4 (IL-4). We have demonstrated that monoclonal plasma cells can be induced in different proportions from PBMC obtained from myeloma patients when exposed in vitro to TNF-alpha and IL-4. Although myeloma cell precursors cannot be distinguished from other cells by morphology, a high number of monoclonal plasma cells was detected in our culture system on day 4 even when plasma cells accounted for less than 0.2% of the cells seeded on day 0. In 16 of the 36 patients with myeloma, monoclonal plasma cells appeared after 4 days. These changes were not observed in PBMC from patients with MGUS or from controls. These findings thus suggest that circulating myeloma cell precursors differentiate into plasma cells in the presence of TNF-alpha and IL-4, and the variation in the number of myeloma cell precursors in peripheral blood could therefore be used as a prognostic parameter in response to chemotherapy in myeloma patients.

Primary extranodal non-Hodgkin's lymphoma in adults: clinicopathological and survival characteristics

Among 318 cases of non-Hodgkin's lymphoma (NHL) treated in our unit, 145 (45.6%) had primary extranodal NHL (PE-NHL). The stomach was the most common site (42.1%), followed by the PE-NHL of the head and neck region. Histologically aggressive histologies (65.5% intermediate and 20.7% high grade) predominated. 89.6% of the cases were localized (stage IE, 51% and stage II, 38.6%) but 28% had B symptoms. CR was achieved in 82.1% of the cases. 5-years disease free survival and overall survival were both 65%. Factors that influence prognosis were stage and high grade histology. Among various primary sites the Waldeyer's ring, small intestine and testes had the worse prognosis. Compared to nodal NHL, the PE-NHL were more frequently localized, belonged more often to aggressive histologies and had more often distal extranodal relapses. CR rates and disease free and overall survival were significantly better for PE-NHL. The survival rates, however, listed according to stage and histology for nodal and PE-NHL were not different. We conclude that although PE-NHL differed from nodal NHL in several respects, prognosis is mainly a factor of stage and histology rather than of the primary localization per se.

Osteoclast function in Paget's disease and multiple myeloma

Paget's disease of bone and multiple myeloma are characterized by increased numbers of osteoclasts and markedly increased bone resorption at the sites of the disease. In Paget's disease the osteoclasts are abnormal morphologically and contain viral-like nuclear inclusions, but in multiple myeloma the osteoclasts are normal. The bone lesions in both Paget's disease and multiple myeloma appear to be due to local stimulation of osteoclast formation and bone resorption. In situ hybridization techniques, bone marrow cultures, and cytokine assays have been used to examine osteoclast function in Paget's disease and multiple myeloma. Interleukin-6 (IL-6) has been implicated as a potential mediator for the increased osteoclast activity in both diseases. In Paget's disease, IL-6 is produced by the osteoclasts, the osteoclasts express IL-6 receptors and IL-6 mRNA, and increased levels of IL-6 are present in the marrow plasma and serum of these patients. Similarly, increased levels of IL-6 have been detected in sera from some patients with multiple myeloma. Multiple myeloma cells do not produce IL-6 in vivo but marrow stromal cells or the osteoclasts may be the source of IL-6 in multiple myeloma. IL-6 is a growth factor for multiple myeloma cells, and treating patients with anti-IL-6 decreases the tumor burden in some patients. Thus, IL-6 may be an autocrine/paracrine factor in both Paget's disease and in multiple myeloma. Multiple myeloma cells also produce osteoclast activating factors (OAFs) that can stimulate osteoclast formation and activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunotherapy of multiple myeloma

In 1994, an estimated 12,700 new cases of multiple myeloma (MM) will be diagnosed in the USA and 9,800 patients will die from this disease. At present, a cure for MM has not been achieved with any chemotherapeutic regimen. Therefore, it is important to develop novel therapeutic approaches to treat this fatal disease. This review focuses on new concepts in the immunotherapy of MM. Thus far, interferons and anti-human interleukin (IL)-6 monoclonal anti-bodies (MAbs) have been used to treat patients with this disease. Bone marrow transplantation using autologous marrow purged with MAbs and complement, with anti-myeloma immunotoxins (ITs), or MAb-magnetic bead conjugates has been reported. Adoptive cellular therapy, in vivo with anti-CD3 and IL-2, as well as transplantation of purified autologous CD34+ peripheral blood stem cells, is now being evaluated in clinical trials. Anti-human IL-6 receptor (IL-6R) and anti-CD54 (ICAM-1) MAbs have shown promising results in the therapy of human myeloma cell lines in SCID mice, while an IL-6 antagonist protein, anti-gp130 MAbs, recombinant soluble gp130, anti-B7, anti-HLA-DR, and recombinant soluble CD16 also inhibit the growth of myeloma cell lines in vitro. These experimental therapeutic modalities hold promise for use in humans and may also provide further insights into the pathogenesis of MM.

Tumour necrosis factor-alpha and interleukin 4 promote the differentiation of myeloma cell precursors in multiple myeloma

The effects of tumour necrosis factor-alpha (TNF-alpha) and interleukin 4 (IL-4) on peripheral blood mononuclear cells (PBMC) from 36 patients with multiple myeloma (MM), 12 with monoclonal gammopathy of undetermined significance (MGUS) and 21 normal controls, were investigated. In 16/36 patients with MM, monoclonal plasma cells appeared after 4d in cultures containing TNF-alpha and IL-4. These changes were not observed in PBMC from patients with MGUS or from normal controls. These findings suggest that myeloma cell precursors do exist in the peripheral blood of MM patients and differentiate into plasma cells in the presence of TNF-alpha and IL-4. Based on these observations, we think that the variation in the number of myeloma cell precursors in peripheral blood could be used as a prognostic parameter of response to chemotherapy in myeloma patients. In addition, this assay may be useful to distinguish early-stage MM from MGUS.

Recent progress in multiple myeloma

Multiple myeloma is recognized as a neoplasm of phenotypically mature plasma cells which produces a variety of clinical symptoms related both to tumour infiltration of the bone marrow and cytokine production. The latter results in bone disease and a complex interactive network between plasma cells, marrow stromal cells and other hematopoietic cells. This serves to sustain the myeloma proliferative pool and promote maturation and secretion of monoclonal immunoglobulin. Whereas the recognizable tumour cells in myeloma are the most mature B cells, early lymphoid cells are involved in the disease and probably represent the proliferative pre-plasma cell compartment. The definition of the myeloma 'stem cell' remains controversial, but our understanding of early pre-plasma cell differentiation in multiple myeloma has been aided by studies on normal non-neoplastic equivalents. Techniques like high resolution flow cytometry, flow cytometric DNA analysis and improvements in our ability to obtain karyotypic data in multiple myeloma will improve our understanding of myeloma cell biology, hopefully yielding new prognostic information. Finally, improvements in assessing prognosis will help identify patients whose survival with standard therapy is limited and who may require innovative or aggressive treatment protocols. These individuals must be separated from patients who either require no initial therapy or who are likely to have good outcomes with standard approaches.

Expression of GpIb on plasma cells in a patient with monoclonal IgG and acquired von Willebrand disease

To get insights into the pathogenesis of acquired von Willebrand disease associated with plasma cell dyscrasias, we searched for the expression of the physiological von Willebrand factor receptor, the GpIb/GpIX complex, on bone marrow plasma cells. The monoclonal spike in our patient corresponded to IgG kappa molecules; there was no plasma inhibitor to vWF:Ag or vWF:RiCoF. The bone marrow contained 1-2% plasma cells. Fresh bone marrow cells or plasma cells enriched bone marrow cells after a 48 h in vitro culture in the presence of interleukin 6 were stained by an immuno alkaline phosphatase technique using monoclonal antibodies (mAb) to von Willebrand factor, GpIb alpha and beta chain, GpIIb/IIIa and Gp IX. Two different mAb to GpIb alpha chains reacted with the majority (75%) of plasma cells whereas all other reagents yielded no staining. Malignant plasma cells from patients with multiple myeloma without haemostatic disorder were unreactive with anti-GpIb mAb. These data suggest that in some patients with acquired von Willebrand syndrome there is a GpIb mediated selective adsorption of von Willebrand factor on clonal plasma cells.

The involvement of adhesion molecules in the biology of multiple myeloma

Multiple myeloma represents a B cell malignancy characterized by a monoclonal proliferation of plasma cells. A striking feature of the disease is the tendency of the malignant plasma cells to affect mainly the bone marrow environment and to invade the peripheral blood only in the terminal stage. The growth of myeloma plasma cells is believed to be regulated by a functional interplay between the tumor cells and the bone marrow stroma, involving the action of various cytokines. This growth control is most probably mediated by close cellular contact of the myeloma cells and marrow stromal components. Therefore it can be assumed that myeloma plasma cells possess the ability to interact with the bone marrow stroma. Until now the adhesive mechanisms that may underlie this interaction, remain undetermined. We investigated the expression of several adhesion molecules on bone marrow plasma cells in myeloma patients and normal controls. Normal as well as malignant plasma cells were found to be strongly positive for the intercellular adhesion molecule ICAM-1, the fibronectin receptor VLA-4 and the lymphocyte homing receptor CD44. In addition, a much weaker expression of the second fibronectin receptor VLA-5, the laminin receptor VLA-6 and the vitronectin receptor CD51 was demonstrated. In contrast to normal plasma cells, myeloma cells can also express the neural cell adhesion molecule N-CAM. In this report we discuss the possible role of adhesion molecules in the pathogenesis and clinical evolution of multiple myeloma.