Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The genetic basis for the development of multiple myeloma (MM) remains poorly understood, in part because MM has thus far been relatively refractory to cytogenetic analysis. The few cases karyotyped have pointed to involvement of 11q13, site of the BCL1 proto-oncogene, or of 8q24, site of the MYC proto-oncogene. A recent molecular study detected rearrangements distal to the MYC gene in 16% of MM, using the MLVI-4 probe. The immunocytochemical demonstration of BCL2 protein overexpression in at least some cases of MM has suggested the possibility of translocation-mediated deregulation of the BCL2 proto-oncogene. The configuration of the BCL2 gene in MM, however, has not yet been defined using all available breakpoint probes. To address these issues, we studied 17 patients with plasma cell dyscrasias (16 MM, 1 plasmacytoma) by Southern blotting using the major breakpoint region (MBR), minor cluster region (MCR), and 5' cDNA (pB16) BCL2 breakpoint probes; with the BCL1 major translocation cluster (MTC) breakpoint probe; and with a probe to the MYC-associated MLVI-4 region (PA1.3SB). In all 17 cases, rearrangement of one or both alleles of the immunoglobulin heavy chain gene had been demonstrated, thereby confirming the presence of tumor DNA in the samples studied. None of the cases tested showed a rearrangement with the MBR BCL2 (0/16), MCR BCL2 (0/17), 5' cDNA BCL2 (0/16), BCL1 MTC (0/15), or MLVI-4 (0/15) probes. These results suggest that if BCL2 deregulation does indeed occur in MM, a mechanism other than translocation must be involved in most cases. Furthermore, rearrangements distal to the MYC gene, in the region of the MLVI-4 probe, may be less common than previously thought. Finally, a significant proportion of translocation breakpoints in band 11q13 may not be detected by the BCL1 MTC probe in MM, as is true in lymphomas.
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PMID:Proto-oncogene analysis in multiple myeloma. 141 86

Two hybridoma cell lines producing monoclonal antibodies (MAbs) to mycoplasmas were established by fusion of mouse myeloma and spleen cells obtained from mice immunized with whole cell Mycoplasma pneumoniae antigens. The MAbs designated as MYC-4 and MYC-9 bound to a single M. pneumoniae protein band with approximate molecular weights of 150,000. In dot-EIA both MAbs reacted with ten Mycoplasma spp., two serovars of Ureaplasma urealyticum and Acholeplasma laidlawii. The MAbs have great potential to be used as an antibody probe for the rapid screening of cell cultures and hybridomas for mycoplasmal contamination.
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PMID:Development and application of monoclonal antibodies for the detection of cell infecting mycoplasmas. 251 56

The immunohistochemical expression of C-myc p62 oncoprotein was investigated using the immunoperoxidase method and the monoclonal antibody (Mab) MYC 1-9E10 in bone marrow paraffin sections. 180 cases of multiple myeloma (MM) were studied. C-myc expression was found to correlate well with the grade of malignancy, type of myeloma and tumor cell burden (p < 0.001). A relationship was also observed between C-myc p62 and IgA-secreting myelomas. It was found that intermediate grade myelomas are heterogeneous as far as C-myc expression is concerned. Our findings strongly suggest that C-myc might be involved in myelomutagenesis. The evaluation of its expression in MM may be helpful in determining the grade of malignancy and possibly the biological behaviour of this tumor.
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PMID:Expression of C-myc p62 oncoprotein in multiple myeloma: an immunohistochemical study of 180 cases. 835 31

Abnormalities involving the 14q32 region are recurrent chromosomal changes in plasma cell malignancies. Recent preliminary molecular analyses found IGH rearrangements in almost 100% of human myeloma cell lines and in 75% of patients. However, no systematic study analyzing the nature of the partner chromosomal regions have been reported thus far. To define the exact incidence of illegitimate IGH rearrangements and the respective incidence of partner genes cloned to date, we analyzed 141 patients with either multiple myeloma (MM, n = 127) or primary plasma cell leukemia (PCL, n = 14) using fluorescence in situ hybridization. The overall incidence of illegitimate recombinations was 57% (80 of 141 patients). Analysis of this incidence according to Durie and Salmon stage, patients' status, i.e., MM versus primary PCL and diagnosis versus relapse, immunoglobulin type and subtype, and beta2-microglobulin value, did not show any correlation. To analyze the nature of the partner chromosomal region, we selected probes specific for the following genes: FGFR3 (4p16), MYC (8q24), CCND1 (11q13), MAF (16q23), and BCL2 (18q21). These probes, combined with differentially labeled 14q32 probes, were used for dual-color fluorescence in situ hybridization on interphase plasma cells. Among the 80 patients with illegitimate IGH rearrangement, we identified 23 IGH-CCND1 fusion cases [i.e., t(11;14)], 17 IGH-FGFR3 fusion cases [i.e., t(4;14)], 3 IGH-MYC fusion cases [i.e., t(8;14)], and only one IGH-MAF fusion case. No IGH-BCL2 fusion case was detected. In 37 of 80 patients, none of these partner genes was involved. Analysis of cases with specific translocations according to their bioclinical features at diagnosis did not show any correlation. This study demonstrated that CCND1 and FGFR3 genes are involved together in about 50% of MM and primary PCL patients with illegitimate IGH rearrangements.
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PMID:High incidence of translocations t(11;14)(q13;q32) and t(4;14)(p16;q32) in patients with plasma cell malignancies. 986 13

Chromosomal rearrangements of the MYC locus, which often involve the IG loci, are recurrent events in multiple myeloma (MM) and plasma cell leukemia (PCL). We used dual-color fluorescence in situ hybridization (FISH) to characterize the breakpoint locations of chromosomal translocations/rearrangements involving the MYC locus at 8q24 found in a panel of 14 MM cell lines and 70 primary tumors (66 MM and 4 PCL). MYC locus alterations were observed in 21 cases: MYC/IG (mainly IGH@) fusions in 11 cell lines and three patients (2 MM and 1 PCL), and extra signals and/or abnormal MYC localizations in seven patients (5 MM and 2 PCL). Fourteen of these cases were investigated by FISH analyses by use of a panel of BAC clones covering about 6 Mb encompassing the MYC locus. The breakpoints were localized in a region 100-250 kb centromeric to MYC in four cases, a region 500-800 kb telomeric to the gene in four cases, and regions > or = 2 Mb centromeric or telomeric to MYC in five cases. Two different breakpoints were detected in the KMS-18 cell line, whereas the insertion of a MYC allele was found in a complex t(16;22) chromosomal translocation in the RPMI8226 cell line. Our data document a relatively high dispersion of 8q24 breakpoints in MM.
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PMID:Heterogeneous pattern of chromosomal breakpoints involving the MYC locus in multiple myeloma. 1275 24

The coexistence of chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) is rare, and there is no consensus about the clonal relationship of the two disorders when they occur in the same individual. We investigated chromosomal abnormalities in two patients with concurrent CLL and MM using interphase fluorescence in situ hybridization (FISH) with a panel of region-specific DNA probes. In patient 1, the clonal plasma cells harbored IgH translocations (14q32); however, FISH with probes for the four most frequent IgH partner genes in MM (CCND1, FGFR3, MAF, and MYC) did not detect translocations involving any of them. The CLL cells were characterized by deletions of 13q14, 11q23, and 17p13, as well as trisomy 12, none of which were found in the MM cells. In patient 2, deletions of 13q14 and 17p13 were detected in CLL cells, but no cytogenetic abnormalities were found in the MM cells. Both patients had relapsed MM following chemotherapy and had autologous stem-cell transplant, whereas their CLL has been stable and not requiring treatment. Our results show that the cytogenetic profiles differ between CLL and MM within the same patients, and provide evidence for two distinct malignant clones in both patients.
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PMID:Molecular cytogenetic abnormalities in patients with concurrent chronic lymphocytic leukemia and multiple myeloma shown by interphase fluorescence in situ hybridization: evidence of distinct clonal origin. 1469 40

Multiple myeloma is characterized by the accumulation of malignant plasma cells in the bone marrow. While there have been many attempts to genetically recapitulate this disease in animal models, few reports describe plasma cell tumors that exhibit bone marrow involvement. We recently described a Bcl-X(L) transgenic mouse that developed polyclonal non-malignant B-cell expansions in the bone marrow and lymphoid organs. In this report, we describe induction of plasma cell tumors in littermate control and Bcl-X(L) transgenic mice with a retrovirus expressing v-Abl and c-Myc. Nearly 100% of the ABL-MYC-infected littermate control and Bcl-X(L) mice developed plasma cell tumors. There was no difference in tumor latency in young mice infected; however, following ABL-MYC infection, aged Bcl-X(L) mice demonstrated a median survival of 9 weeks, while littermate control mice demonstrated a median survival of 19 weeks. Interestingly, while both littermate control and Bcl-X(L) mice infected with the ABL-MYC retrovirus developed extramedullary plasma cell tumors, only the ABL-MYC-infected Bcl-X(L) mice, but not the ABL-MYC-infected littermate control mice, developed bone marrow plasma cell tumors with characteristic radiolucent bone lesions. Tumor cell populations were clonally related, and analysis of tumor immunoglobulin genes demonstrated evidence consistent with somatic hypermutation. This report implicates an unidentified role of Bcl-X(L) in bone marrow plasma cell tumor formation, as ABL-MYC retroviral infection only elicits bone marrow plasma cell tumors in mice that ectopically express Bcl-X(L) in their B- and plasma cells.
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PMID:ABL-MYC retroviral infection elicits bone marrow plasma cell tumors in Bcl-X(L) transgenic mice. 1572 78

The cellular oncogene MYC and plasma cell growth, differentiation, and survival factor IL-6 play critical roles in the natural history of human plasma cell neoplasms such as multiple myeloma (MM). Myc and IL-6 also are at the center of neoplastic plasma cell transformation in BALB/c mice that carry a human IL-6 transgene and, therefore, predictably develop plasmacytomas (PCTs). We showed previously that, much like advanced MM or human myeloma cell lines (HMCLs), in which MYC is frequently deregulated in cis because of complex cytogenetic aberrations juxtaposing MYC to immunoglobulin enhancers, IL-6 transgenic PCTs commonly deregulate Myc in cis by chromosomal translocation, predominantly T(12;15)(Igh-Myc). In this article, we show that, analogous to primary MM in which MYC is mostly deregulated in trans by signaling pathways converging at the MYC promoter, IL-6 transgenic PCTs sometimes develop in the absence of Myc translocations, thus activating Myc in trans. We present cytogenetic and molecular evidence on two IL-6 transgenic PCTs that contained overexpressed Myc protein but lacked T(12;15)(Igh-Myc) and two related Myc--deregulating translocations that juxtapose Myc to immunoglobulin light-chain instead of heavy-chain enhancers: T(6;15)(Igkappa-Pvt1) and T(15;16)(Pvt1-Iglambda). We conclude that Myc translocations are not strictly required for IL-6-driven PCT development in mice. IL-6 transgenic PCTs may provide a valuable model system for elucidating both trans and cis mechanisms of Myc deregulation of great relevance for MYC deregulation in human MM.
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PMID:Extraosseous IL-6 transgenic mouse plasmacytoma sometimes lacks Myc-activating chromosomal translocation. 1575 Oct 44

There appear to be two pathways involved in the pathogenesis of premalignant non-immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM). Nearly half of tumors are nonhyperdiploid, and mostly have one of five recurrent IgH translocations: 16% 11q13 (CCN D1), 3% 6p21 (CCN D3), 5% 16q23 (MAF), 2% 20q12 (MAFB), and 15% 4p16 (FGFR3 and MMSET). The remaining hyperdiploid tumors have multiple trisomies involving chromosomes 3, 5, 7, 9, 11, 15, 19, and 21, and infrequently one of these five translocations. Although cyclin D1 is not expressed by healthy lymphoid cells, it is bi-allelically dysregulated in a majority of hyperdiploid tumors. Virtually all MM and MGUS tumors have dysregulated and/or increased expression of cyclin D1, D2, or D3, providing an apparent early, unifying event in pathogenesis. The patterns of translocations and cyclin D expression (TC) define a novel classification that includes eight groups: 11q; 6p; MAF; 4p; D1 (34%); D1+D2 (6%); D2 (17%); and none (2%). The hyperdiploid D1 group is virtually absent in extramedullary MM and MM cell lines, suggesting a particularly strong dependence on interaction with the bone marrow microenvironment. Despite shared progression events (RAS mutations, MYC dysregulation, p53 mutations, and additional disruption of the retinoblastoma pathway), the phenotypes of MGUS and MM tumors in the eight TC groups is determined mainly by early oncogenic events. Similar to acute lymphocytic leukemia, MM seems to include several diseases (groups) that have differences in early or initiating events, global gene expression patterns, bone marrow dependence, clinical features, prognosis, and response to therapy.
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PMID:Molecular pathogenesis and a consequent classification of multiple myeloma. 1615 16

The authors have recently reported that gene-targeted iMyc(Emu) mice that carry a His(6)-tagged mouse Myc cDNA, Myc(His), just 5' of the immunoglobulin heavy-chain enhancer, Emu, are prone to 'spontaneous' neoplasms of the B-lymphocyte lineage. The present study has used histological, immunohistochemical, and molecular genetic methods to investigate a subset of these neoplasms referred to as extraosseous plasmacytomas (PCTs). It is shown that 20.8% (20/96) of tumour-bearing iMyc(Emu) mice on a mixed genetic background of segregating C57BL/6 and 129/SvJ alleles develop PCT by 500 days. The Myc(His)-induced PCTs produced monoclonal immunoglobulin and developed in the gut-associated lymphoid tissue (GALT), particularly the mesenteric node and Peyer's patches. The PCTs overexpressed Myc(His), at the expense of normal Myc, and exhibited gene expression changes on cDNA macroarrays that were consistent with Myc(His)-driven neoplasia. Surprisingly, in one of three PCT-derived cell lines, Myc(His) was 'replaced' by a naturally occurring T(12;15) translocation, which changed the mode of Myc deregulation from gene insertion (Myc(His) transgene) to chromosomal translocation (juxtaposition of normal Myc to the immunoglobulin heavy-chain locus Igh). These findings provide evidence that recreation of the mouse PCT-associated T(12;15)(Igh(Emu)-Myc) translocation by gene insertion in mice results in the predictable development of PCTs in approximately one-fifth of the tumour-bearing mice. Myc(His)-driven PCTs recapitulate aspects of human plasma cell neoplasms, for which relatively few models exist in mice. For example, PCT development in the iMyc(Emu) mice may provide a good system to study the mechanism by which human MYC facilitates the progression of plasma cell myeloma (multiple myeloma) in humans.
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PMID:Plasma cell tumour progression in iMycEmu gene-insertion mice. 1648 95


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