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)

If micrococcal nuclease is allowed to digest chromatin as it exists inside intact nuclei isolated from mouse myeloma tissue culture cells, more than 60% of the DNA can be isolated as a homogeneous fragment on a sucrose gradient. Analytical ultracentrifugation indicates that the protected DNA is native, unnicked, and about 140 +/- 10 base pairs long. After less extensive nuclease digestion, the protected DNA migrates in gels in lengths which are integral multiples of this 140 base pair "monomer" band. A submonomer band, 105 "/- 10 base pairs long, can also be detected. Similar digestion patterns were obtained by two different nuclear isolation procedures and even when intact cells were gently lysed directly in the digestion medium. These results confirm and extend the chromatin digestion studies of previous investigators and provide support for a subunit model for eukaryotic chromatin. The single strand specific S1 nuclease did not digest intranuclear chromatin under the conditions used.
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PMID:Evidence for a subunit structure of chromatin in mouse myeloma cells. 117 64

An HLA-E-specific oligonucleotide probe was used to study the expression of HLA-E. This probe detects two HLA-E transcripts, 1.8 and 2.7 kb in size, which are present in varying ratios in all tissues and cell lines investigated. We demonstrate that alternative poly(A) site usage accounts for the differential regulation of the two HLA-E mRNA species. Sequence analysis of three cDNA clones, representing the two transcripts of HLA-E, and of an HLA-E gene encoded by cosmid cd3.14, revealed identity of gene and cDNA in the 3' untranslated region. S1 nuclease protection assays confirmed that the two HLA-E transcripts are not alternative splicing products. Introduction of cd3.14, together with human beta 2 m into the murine myeloma cell line P3X63-Ag8.653, resulted in a cell surface expression of an HLA-class I heavy chain detectable by indirect immunofluorescence whereas transfection into the human beta 2m expressing mouse L cell line, J27 was negative with regard to cell surface expression. Cell surface labeling of transfectants and immunoprecipitation with a monomorphic HLA class I-specific antibody or an antibody against human beta 2m confirmed the presence of an HLA-E H chain on the cell surface. These results indicate that the HLA-E gene codes for a class I H chain that can be expressed on the cell surface.
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PMID:The HLA-E gene encodes two differentially regulated transcripts and a cell surface protein. 140 23

Previous studies had shown that several phenotypic markers expressed by several strains of mice (C58, AKR, PL, RF) involve a light chain group, called V kappa Ser, encoded by a single germ-line gene (Igk-VSera). Most other inbred strains (e.g., BALB/c) contain an allele (Igk-VSerb) which differs from Igk-VSera both in coding regions and in an upstream octamer region known to be important for transcription. Since no evidence for expression of the Igk-VSerb gene product has been observed, experiments were undertaken to determine whether the alteration in the regulatory octamer region of BALB/c might have rendered it defective for transcription. The upstream octamer-containing region of a cloned functional V kappa Ser gene expressed by the C.C58 myeloma M75 was replaced by the corresponding region from BALB/c or deleted entirely. Constructs were transfected into J558L cells and quantity of transcription and site of transcription initiation were compared. Results suggest that the BALB/c octamer (CTTTGCGT), which differs at two of eight nucleotides from the consensus octamer sequence (ATTTGCAT), is fully functional in transcription initiation. This is consistent with results of S1 nuclease protection experiments which indicate the presence of small amounts of correctly initiated V kappa Ser-related RNA in BALB/c spleen.
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PMID:Analysis of the effect of a strain-specific alteration in the upstream octamer region on transcription of a mouse V kappa Ser light chain gene. 244 85

We isolated and characterized LP1.2, a mouse myeloma mutant with a deletion of at least 4 kilobases (kb) immediately 3' of the alpha gene and introduction of at least 5 kb of novel (nonimmunoglobulin) sequence in its place. A 6.2-kb genomic EcoRI fragment from the mutated allele was cloned, and a subfragment was sequenced. The deletion begins 11 base pairs (bp) beyond the normal site of cleavage and polyadenylation for the secreted form of alpha mRNA. A short direct repeat, eight copies of the 17-mer GCCT ATAGAAGTAAGGA, is located at the junction of the alpha and novel sequences. The first 4 bp of the 17-mer are identical to the last 4 bp of the alpha sequence. Novel sequences downstream of the direct repeats in LP1.2 include a low-copy-number sequence flanked by two distinct, highly repetitive elements. The low-copy-number portion of the novel sequence appears on a single 30-kb EcoRI fragment in several myelomas and in liver DNA; one copy of this fragment has rearranged in cell line W3129, and this allele has rearranged a second time in LP1.2. LP1.2 contains low levels of apparently normal alpha protein and mRNA. The S1 nuclease protection of nuclear and cytoplasmic RNAs shows that cleavage and polyadenylation are efficient and accurate and that they occur without the accumulation of aberrant transcripts. Alpha transcription in isolated nuclei is decreased sevenfold in LP1.2 relative to its parent, which accounts for the low steady-state levels of cytoplasmic alpha mRNA and protein in LP1.2. Decreased alpha transcription could result either from the deletion of a positive regulator in the 3' flanking region or from the introduction of novel sequences which exert a negative effect.
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PMID:Myeloma mutant with a novel 3' flanking region: loss of normal sequence and insertion of repetitive elements leads to decreased transcription but normal processing of the alpha heavy-chain gene products. 302 10

Analysis of the heat-shock response in murine plasmacytomas reveals that, as demonstrated previously for the MPC-11 cell line, the genes coding for the 68-kilodalton heat-shock protein (hsp-68) are not expressed upon heat shock or sodium arsenite treatment. Noninduction is unique to the normally coordinated set of three hsp-68 genes since at least two other heat-shock protein genes (hsp-70 and hsp-89) are properly induced. No other lymphoid cell line was found to possess silent hsp-68 genes. Cell lines examined included a T lymphoma, a pre-B lymphocyte, and a non-B-non-T tumor cell line, as well as an Ig-nonproducing myeloma of undetermined differentiated status. Nonexpression is strain-independent as observed in BALB/c and C3H plasmacytomas. Based on S1 nuclease analysis using a cloned genomic hsp-68 probe, nonexpression is caused by the absence of hsp-68 mRNA following heat shock. A time-course experiment suggests that rapid degradation of mRNA does not occur, implying that the block is most likely at the transcriptional level. Southern blot analysis does not indicate any minor deletions around the region of transcription initiation, at least in the probed hsp-68 gene. These results suggest that the absence of hsp-68 gene expression may be a reflection of the differentiated and (or) transformed state of murine plasma cells, possibly through the absence or deregulation of a regulatory factor required for induction of heat-shock genes.
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PMID:Murine plasmacytomas constitute a class of natural heat-shock variants in which the major inducible hsp-68 gene is not expressed. 303 May 21

A new method for the measurement of DNA damage in individual cells treated with alkylating agents is described. The method is based on the binding of anti-DNA monoclonal antibody to DNA in situ. Monoclonal antibody F7-26 was obtained by fusion of mouse myeloma cells with spleen cells isolated from a mouse immunized with DNA treated by nitrogen mustard (HN2). Binding of antibody was evaluated by flow cytometry with indirect immunofluorescence. No binding of antibody to DNA in non-treated HeLa S3 cells was detected. Treatment of cells with HN2 or L-phenylalanine mustard induced binding of antibody to DNA in situ. Binding of antibody was observed after treating cells with doses of drugs which reduced the surviving fraction below 20%. Intensity of binding increased in proportion to the drug dose. Two-parameter analysis for the antibody binding and DNA content showed no binding of antibody to replicating DNA in control cells. In HN2-treated cells a cell subset with the lowest antibody binding was observed among cells in G1 phase. Binding of antibody to DNA in HN2-treated cells was eliminated by single-strand (ss) specific S1 nuclease. In competition assay, antibody was inhibited by thermally denatured DNA, but not by native double-stranded (ds) DNA, RNA, nucleosides and deoxyribohomopolymers. Binding of monoclonal antibody specific for the determinants expressed on ssDNA to the cells treated with alkylating agents may be attributed to local DNA denaturation. Potentiation of L-phenylalanine mustard cytotoxicity by buthionine sulfoximine or hyperthermia was accompanied by increased antibody binding to cellular DNA. Immunoreactivity of cells with the monoclonal antibody F7-26 may be a useful probe for the assessment of cell damage induced by alkylating agents, especially in heterogeneous cell populations.
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PMID:Detection of DNA damage in individual cells by flow cytometric analysis using anti-DNA monoclonal antibody. 303 52

We report here a 54 base pair deletion in the CH3 exon of the alpha gene in the mouse myeloma W3129. This deletion results in a loss of 18 amino acids and a change from a glycine to a serine at position 464. The extent of the deletion was determined by sequencing a portion of CH3 cloned from a variant of W3129, and S1 nuclease protection showed the deletion pre-exists in the parental cell line. The deletion removes the donor splice site normally used in joining CH3 to the alpha membrane (MB) exon when forming MB-specific mRNA. Examination of cytoplasmic RNA by blot hybridization and S1 nuclease protection using MB-specific probes showed a complete lack of membrane mRNA in W3129 and its derivatives. An RNA transcript of unknown origin and function which includes sequences from the CH3-MB intron was seen in W3129 and in J558, an IgA, lambda myeloma with specificity for alpha (1----3) linked dextrans. We discuss the possible influence of the mutation on the W3129 protein. In contrast to the other myelomas studied in this laboratory, light chain loss variants are readily isolated from W3129 and are stable in their production of heavy chain [Dackowski and Morrison (1981) Proc. natn. Acad. Sci. U.S.A. 78, 7091-7095].
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PMID:The IgA myeloma W3129 contains a deletion in CH3 which prevents the formation of the membrane form of heavy chain mRNA. 313 59

Mouse ornithine decarboxylase (ODC) genomic clones were isolated from a bacteriophage lambda genomic library representing mouse myeloma 653-1 cells which over-produce ODC due to amplification of an active ODC gene. Sequence analysis of the amplified ODC gene revealed that ODC mRNA is encoded by 12 exons, 10 of which (exons 3 to 12) code for the ODC protein. Exon 12 also corresponds to the 3' noncoding region of the two species of ODC mRNA which are formed by alternative utilization of two polyadenylation signals separated from each other by 422 nucleotides. The transcription initiation site was mapped by S1 nuclease protection and by primer extension analysis. The 5' flanking region is extremely rich in G + C and contains typical promoter motifs such as the TATA box and SP1 transcription factor binding sites. Joining the 5' flanking region to the Escherichia coli chloramphenicol acetyltransferase structural gene and its introduction into mouse cells resulted in the expression of a high level of chloramphenicol acetyltransferase activity. Comparing the sequence of the ODC gene to our previously published sequence of ODC cDNA revealed a disagreement between the sequences located 5' to the AvaI site and demonstrated that this region of our previously reported cDNA represents a cloning artifact. The portion of the correct 5' noncoding region encoded by exon 1 is extremely rich in G + C and includes potential secondary structures which may be involved in translational regulation of ODC mRNA.
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PMID:Isolation and characterization of the mouse ornithine decarboxylase gene. 337 2

Mouse c-myb gene transcripts in various cells of haemopoietic origin were analysed using S1 nuclease and RNase mapping techniques and by Northern blotting. It was found that the prevalent 3.8-kb c-myb mRNA present in thymocytes, T cell leukaemias, myelomonocytic leukaemias, erythroleukaemias and myeloid stem cells was initiated at several cap sites mapping within a region 97-244 bp upstream from the protein coding sequence. Utilization of additional cap sites mapping further upstream was also observed in certain cells, most notably thymocytes, and this gave rise to RNA species (4.3-5.6 kb) larger than the presumptive mRNA. In contrast, myeloma cell c-myb transcripts, which are much less abundant than those in more immature haemopoietic cells, were found to be initiated at a restricted set of cap sites mapping 244-277 bp upstream of the coding sequence. Hence, these data suggest that the abundance of the c-myb mRNA may be regulated by a process involving selective utilization of mRNA cap sites. Sites hypersensitive to DNase I were associated with mRNA cap sites in cells that expressed c-myb.
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PMID:Multiple c-myb transcript cap sites are variously utilized in cells of mouse haemopoietic origin. 360 90

A series of mouse myeloma mutants, derived from a cell line of the murine MPC-11 tumor (gamma 2b, kappa), resemble human heavy-chain disease in their loss of an internal domain (exon). In these mutants, most of the gamma 2b CH1 exon was present in the nuclear RNA but was removed during splicing to form the mature cytoplasmic RNA. Amino acid sequence studies of one mutant (10.1) are consistent with the loss of the complete CH1 domain. A second mutant cell line (I17) derived from 10.1 and containing the same CH1 alteration was shown by S1 nuclease protection experiments to have an additional mRNA deletion spanning the CH2-CH3 domain boundary. This second deletion was shown to result from a genomic alteration that provided a marker for the isolation of the expressed H-chain allele. To determine the basis of the CH1 splicing defect, the 117 genome-expressed gamma 2b constant region DNA was cloned. Sequence studies showed a deletion of 99 nucleotides around the 3' end of the CH1 domain, which removed the splice site and flanking DNA, apparently causing the aberrant splicing of the RNA transcript. The sequence deleted in the mutant is flanked by short repeats of the octameric sequence CCAGCCAG in the wild-type gene. In the mutant, one copy of the repeat, in addition to the sequences between the repeats, has been lost.
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PMID:Loss of a consensus splice signal in a mutant immunoglobulin gene eliminates the CH1 domain exon from the mRNA. 609 57


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