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)

In order to study the heterogeneity of the anti-erythrocyte auto-antibody response in NZB mice, we have developed hybridomas producing monoclonal auto-antibodies with anti-erythrocyte activity. These monoclonals were prepared by fusion of NZB splenocytes with the P3 X 63.Ag8 myeloma and were screened for activity by indirect immunofluorescence using flow cytometry. We have produced a variety of monoclonal anti-red cell auto-antibodies that have differing antigenic reactivities and immunoglobulin isotypes. Eleven monoclonal antibodies extensively studied thus far react with intact mouse erythrocytes, whereas only two of the eleven also cross react with sheep erythrocytes and bromelain treated mouse erythrocytes. These results suggest that the fusion pattern may represent the range of anti-red cell auto-antibodies found in the intact NZB mouse, with the exception of monoclonal auto-antibodies against cryptic red cell auto-antigens, which were not demonstrated in this initial fusion study.
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PMID:Monoclonal anti-erythrocyte auto-antibodies from unimmunized NZB mice. 692 51

Human CD1 genes are a family of five non-polymorphic genes that, although homologous to both class I and II major histocompatibility complex genes, map to chromosome 1. Only three of the antigens, CD1a, -b, and -c, have been clustered with monoclonal antibodies. They are noncovalently associated with beta 2-microglobulin and may function as nonclassical antigen-presenting molecules. Here we analyze their expression in mouse myeloma transfectants and human thymocytes and find mRNA splicing complexity. This manifests itself as incomplete splicing, alternative splicing, utilization of cryptic splice sites, and the generation of alternative reading frames. In the case of CD1A transfectants, we demonstrate that the major protein product is secreted and show by amino acid sequence analysis that this is derived from an unspliced transcript. A second major CD1a component appears to be retained intracellularly. The production of alternatively spliced transcripts in the thymus is not a feature of all CD1 genes. Although in the case of CD1A only the transcript encoding the cell surface CD1a isoform is found, CD1C and -E produce complex intrathymic splicing patterns. The CD1C transcripts predict the expression of a secreted CD1c isoform in the human thymus, which we detect in CD1C transfectant culture supernatants. CD1 gene expression is thus characterized by considerable splicing complexity, and the difference between the splicing patterns found in different environments suggests that this is tissue specific.
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PMID:Alternative splicing generates secretory isoforms of human CD1. 751 59

We generated four murine monoclonal antibodies (MAbs) specific for globo-series glycolipids by immunizing C3H/HeN mice with these purified glycolipids adsorbed to Salmonella minnesota followed by fusion with mouse myeloma cells. By use of a wide variety of glycolipids, the precise structures recognized by these MAbs were elucidated through an enzyme-linked immunosorbent assay and an immunostaining on thin-layer chromatography. These four MAbs, designated as BGR23, BGR47, BMR26, and BGR27, exhibited highly restricted binding specificities, reacting only with the globo-series glycolipids Gb3Cer, III3Gal alpha-Gb3Cer, Gb4Cer, and IV3GalNAc alpha-Gb4Cer, respectively, which were used for immunization. None of the other various glycolipids or gangliosides were recognized. We determined the localization of these globo-series glycolipids in adult rat small intestine by means of an immunofluorescence technique with these MAbs. Our study revealed that there is a differential distribution of these glycolipids in the rat tissue. III3Gal alpha-Gb3Cer was demonstrated on the cryptic cells and circular muscle, whereas Gb4Cer was localized on both the circular and longitudinal muscles. The expression of Gb3Cer was associated with the epithelium and the capillary endothelial cells in the lamina propria mucosae as well as with the tunica submucosa, whereas IV3GalNAc alpha-Gb4Cer was detected on the epithelium, capillary endothelial cells in the lamina propria mucosae, and both the muscle layers.
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PMID:Generation of one set of murine monoclonal antibodies specific for globo-series glycolipids: evidence for differential distribution of the glycolipids in rat small intestine. 816 Dec 26

Alterations in kappa light chain expression were demonstrated to originate from genomic changes in the L-V intron (L-IVS) which changed the splicing pattern of the kappa mRNA. In R15, a mutant of mouse myeloma W3129 which produces no kappa light chain, a 358 bp novel sequence element (R15ns) of unknown origin replaced 19 bases of wild-type L-IVS, both altering the normal splicing pattern and activating a cryptic polyadenylation site. Subclones of R15 which reverted to kappa light chain production contained genomic deletions of R15ns and/or the surrounding intron. These deletions led to partial or full restoration of wild type kappa mRNA levels due to further changes in the pattern of mRNA processing. Two cryptic splice acceptor sites and a polyadenylation signal exist in the L-IVS; a cryptic splice acceptor sequence also exists in V kappa. These cryptic sites can be activated by changing the genomic context. It is thus possible to influence light chain expression without altering either the exon sequences or the known regulatory elements. Alterations in splicing patterns also serve to produce kappa light chains with novel variable region sequences and thereby could contribute to antibody diversity. Surprisingly, in the cell line producing this novel kappa light chain, intact alpha heavy chains were secreted in the absence of an apparent association with light chain. These studies also demonstrate that it is not possible to distinguish functional from non-functional genes solely by sequence analysis and that genes can both be inactivated and activated by changes in intron sequences.
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PMID:Intron sequences determine the expression of kappa light chain genes. 830 81

Human myeloma are incurable hematologic cancers of immunoglobulin-secreting plasma cells in bone marrow. Although malignant plasma cells can be almost eradicated from the patient's bone marrow by chemotherapy, drug-resistant myeloma precursor cells persist in an apparently cryptic compartment. Controversy exists as to whether myeloma precursor cells are hematopoietic stem cells, pre-B cells, germinal center (GC) B cells, circulating memory cells, or plasma blasts. This situation reflects what has been a general problem in cancer research for years: how to compare a tumor with its normal counterpart. Although several studies have demonstrated somatically mutated immunoglobulin variable region genes in multiple myeloma, it is unclear if myeloma cells are derived from GCs or post-GC memory B cells. Immunoglobulin (Ig)D-secreting myeloma have two unique immunoglobulin features, including a biased lambda light chain expression and a Cmu-Cdelta isotype switch. Using surface markers, we have previously isolated a population of surface IgM-IgD+CD38+ GC B cells that carry the most impressive somatic mutation in their IgV genes. Here we show that this population of GC B cells displays the two molecular features of IgD-secreting myeloma cells: a biased lambda light chain expression and a C&mu-Cdelta isotype switch. The demonstration of these peculiar GC B cells to differentiate into IgD-secreting plasma cells but not memory B cells both in vivo and in vitro suggests that IgD-secreting plasma and myeloma cells are derived from GCs.
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PMID:The normal counterpart of IgD myeloma cells in germinal center displays extensively mutated IgVH gene, Cmu-Cdelta switch, and lambda light chain expression. 954 29

Cytogenetic studies have shown rearrangements of the Ig heavy chain (IGH) gene at 14q32 in 10-60% of patients with multiple myeloma (MM) or primary plasma cell leukemia (PCL). Analysis of MM patients and human myeloma cell lines (HMCL) using interphase fluorescence in situ hybridization (FISH) and molecular techniques has shown IGH rearrangements in 75% of MM cases and in up to 100% of HMCL. A review of the literature revealed at least 18 different partner chromosomal regions. To investigate whether some of these translocations were recurrent and possibly to identify new partner regions, we developed a set of FISH probes to detect every IGH recombination. We analyzed 28 MM and 4 primary PCL patients with abnormal karyotypes and 12 HMCL. Whereas conventional cytogenetics detected a 14q32 abnormality in only 15% of the patients, FISH detected it in 47% of patients and in 75% of HMCL. The partner chromosome was identified in 10 of 15 patients with a 14q32 rearrangement. Interestingly, the same t(4; 14)(p16;q32) was detected in five patients and three HMCL, i.e., 33% of patients and HMCL with an IGH rearrangement. New partner chromosomal regions have also been identified, i.e., 9p13, 12p11, 12p13, and Xq28, besides the previously reported 8q24, 11q13, 12q24, and 16q24 rearrangements. The genes involved in these new translocations are not known, except for 9p13, where PAX5 was shown to be the partner gene. We conclude that: I) IGH recombinations are frequent but not constant in MM, 2) these rearrangements often occur through cryptic translocations, and 3) the t(4;14)(p16;q32) is one of the most frequent translocations, but many other chromosomal regions may be involved.
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PMID:High incidence of cryptic translocations involving the Ig heavy chain gene in multiple myeloma, as shown by fluorescence in situ hybridization. 989 3

The immunoglobulin (Ig) genes are frequently involved in chromosomal rearrangements with a wide variety of partner loci in multiple myeloma (MM). However, several partner chromosomes have not been detected by conventional cytogenetic methods; for example, 4p16.3 (FGFR3), 6p25.3 (IRF4), and 16q23 (c-maf). To clarify the incidence of t(4;14)(p16.3;q32.3) in primary tumors of MM and to evaluate possible correlations with specific manifestations of the disease, G-banding, double-color fluorescence in situ hybridization (DC-FISH), and/or reverse-transcriptase polymerase chain reaction (RT-PCR) were performed on 40 patients with MM-two with plasmacytoma (PCM) and three with plasma cell leukemia (PCL). All patients were studied by DC-FISH; 40 were studied by G-banding and 36 were studied by RT-PCR. The FISH probes consisted of a cosmid pC385.12 containing the FGFR3 gene, a YAC Y6 containing VH, and a phage Iggamma1-10 containing the gamma1 constant region (Cgamma). We identified eight patients with either FGFR3/Cgamma fusion or FGFR3 overexpression: six patients with both FGFR3/Cgamma fusion and FGFR3 overexpression, one patient with FGFR3/Cgamma, and one with FGFR3 overexpression. FGFR3/Cgamma fusion was demonstrated at a frequency of 19% to 38% on interphase nuclei in seven of the 45 patients. Lytic bone lesions were found to be associated with FGFR3 overexpression. Interphase FISH with FGFR3 and Cgamma probes combined with RT-PCR proved to be an effective tool for detection of this fully cryptic translocation, thus facilitating the characterization of clinical features of MM patients with t(4;14).
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PMID:Interphase detection of t(4;14)(p16.3;q32.3) by in situ hybridization and FGFR3 overexpression in plasma cell malignancies. 1070 76

The t(4;14) translocation is found in approximately 10% of myeloma patients and results in the deregulation of at least two genes, MMSET and fibroblast growth factor receptor 3 (FGFR3), with the formation of a fusion product between MMSET and the immunoglobulin heavy chain (IgH) locus and overexpression of FGFR3. We have analysed a series of 80 patient samples, comprising 67 multiple myeloma (MM) cases and 13 monoclonalgammopathy of undetermined significance (MGUS) cases, using RT-PCR to detect IgH-MMSET fusions. The t(4;14) translocation was detected in 7/67 (10%) myeloma cases and all seven expressed FGFR3 which was not seen in t(4;14)-negative myeloma cases. In the MGUS cases, a similar proportion of t(4;14)-positive cases was found (2/13; 15%), but none of these expressed FGFR3. All patients with detectable FGFR3 expressed both the FGFR3 IIIb and FGFR3 IIIc isoforms, the result of alternative splicing in the ligand binding domain, and exon-deleted variants of FGFR3. We also identified a cryptic splice site in MMSET which results in a 277 amino acid deletion downstream of the breakpoint on der(4). FGFR3 mutation analysis revealed no mutations in the presenting myeloma or MGUS samples. However, we also had access to paired presentation and relapse samples which had been taken from a patient 13 months apart. Both samples had the t(4;14) translocation and overexpressed FGFR3, but only the relapse sample possessed the K650E mutation in the kinase domain of FGFR3. This suggests that targeted mutation in the translocated FGFR3 gene when under the control of the immunoglobulin promoters can occur and may provide one mechanism for disease progression.
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PMID:A molecular study of the t(4;14) in multiple myeloma. 1213 40

Relatively little is known about the cytogenetic features of multiple myeloma (MM) when compared to other hematologic malignancies. The reasons for this are most likely manifold, and include a low mitotic index of the malignant cells and the presence of cytogenetically cryptic abnormalities as well as of complex karyotypes with poor chromosome morphology. In the present study, we have investigated whether various culture conditions may influence the yield of abnormal metaphases in MM and, in the related plasma cell dyscrasias, monoclonal gammopathy of undetermined significance (MGUS) and plasmacytomas (PC). In addition, the possible impact of age, gender, and disease phase on the cytogenetic features has been analyzed. A total of 95 samples from 74 cases (68 MM, three PC, and three MGUS patients) were obtained for cytogenetic analysis. The samples were cultured either in conventional medium or in medium containing IL-6 and GM-CSF, and the culture times varied from 24 to 120 h. In total, 186 cultures were analyzed. Metaphase fluorescence in situ hybridization analysis using probes specific for 14q32, i.e. IGH rearrangements, could be performed in 57 of the 74 cases, and revealed 14q32 aberrations in 10 cases not seen by conventional G-banding. Abnormal karyotypes were detected in 77 (41%) of the 186 cultures, 46 (48%) of the 95 samples, and in 41 (55%) of the 74 patients, revealing a total of 20 chromosomal aberrations previously not reported in plasma cell dyscrasias. We found no evidence that gender, age, disease phase, culture time, or cytokine stimulation significantly influences the karyotypic features of MM.
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PMID:Cytogenetic features of multiple myeloma: impact of gender, age, disease phase, culture time, and cytokine stimulation. 1222 92

Translocations involving the immunoglobulin heavy-chain genes are frequent in multiple myeloma (MM), which can be separated into two groups according to the chromosome number pattern. 14q32 translocations 14q32t are more frequent in hypodiploid than in hyperdiploid karyotypes. However, conventional cytogenetics (CC) misses cryptic translocations, especially t(4;14)(p16;q32). Furthermore, recent interphase fluorescence in situ hybridization (FISH) studies found 14q32t in as many as 75% of MM cases. To identify in which CC group we failed to detect translocations, we designed a study by use of FISH with a dual-color IGH probe on previously R-banded metaphase cells, allowing the detection of both 14q32t and overall chromosomal abnormalities, in a new series of 55 MM with abnormal karyotypes: 4/29 hyperdiploid (14%) and 19/26 hypodiploid (73%) cases had a 14q32t. The t(4;14) was found in 2 hyperdiploid (7%) and 10 hypodiploid (39%) cases. We therefore confirm that 14q32t are much more frequent in hypodiploid than in hyperdiploid MM (P<0.0001) and that cryptic t(4;14)(p16;q32) is strongly associated with hypodiploid karyotypes (P<0.01). Through the use of this reliable assay, only 42% of MM had 14q32t.
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PMID:Further cytogenetic characterization of multiple myeloma confirms that 14q32 translocations are a very rare event in hyperdiploid cases. 1450 97

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