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)

We have determined the variable region sequences of four heavy chains from beta(1-6)D-galactan-binding myeloma proteins. Two of these proteins are identical to position 100 which is located in the third complementarity-determining region (CDR-3). The remaining two differ at a total of 8 positions over the first 100 amino acids, and all of the differences can be explained by single-base mutations at the DNA level. When an assessment is made of the protein segment following CDR-3, which has been termed "J segment" or "FR4," a completely different pattern of variation is observed. The J segments from the four proteins can be divided into two sets. Members of each set share a series of linked amino acids not found in members of the alternative set. The two proteins identical to position 100 have J segments from the two different sets, suggesting that recombination has occurred between V and J genes. An examination of the CDR-3 sequences from the four heavy chains reveals substitutions at positions 100 and 105. Gly is found at 100 in two of the proteins and His in the remaining two. In the two proteins with Gly-100, the following J sequence is limited to one of the two sets of J segments defined by linked amino acids. Similarly, the two heavy chains with His-100 have J segments from the second set. Thus, at the protein level an apparent association is seen between CDR-3 and J segment. If CDR-3 should be found linked to J segment at the DNA level, a new mechanism would be introduced for increasing antibody diversity by recombining various CDR-3 plus J genes with genes coding for the remainder of the variable region. Alternatively, if CDR-3 were coded for by the V gene, then the recombination of V with J may provide an opportunity to introduce mutations in CDR-3. In this case the linkage of amino acids in CDR-3 and the J segments would suggest that recognition signals are used such that certain V genes only pair with a given J gene.
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PMID:Structural evidence for independent joining region gene in immunoglobulin heavy chains from anti-galactan myeloma proteins and its potential role in generating diversity in complementarity-determining regions. 11 Dec 45

The organization of the kappa chain constant region gene was compared in DNA from an immunoglobulin-producing mouse myeloma (MOPC 173) and from liver. In situ hybridization using the Southern blotting technique revealed constant region gene-containing EcoRI-DNA fragments of 14 and 20 kb in the myeloma tissue whereas one EcoRI-DNA fragment with a length of 15 kb was found in liver DNA. After enrichment by RPC-5 chromatography and preparative electrophoresis the 14 kb fragment from MOPC 173 DNA and the 15 kb fragment from liver DNA were cloned in the bacteriophage lambda vector Charon 4A using in vitro packaging. Extensive characterization of the two fragments by restriction endonuclease mapping, in situ hybridization, and electron microscopy (R-loop and heteroduplex) showed that both fragments contain the constant region but no MOPC 173 variable region gene. Both fragments are homologous over a length of 12.5 kb including the constant region but differ from one another starting about 2.7 kb from the 5' end of the constant region gene. This indicates that the 14 kb EcoRI-DNA fragment from the myeloma tissue clearly resulted from somatic DNA rearrangement although it does not seem to carry the MOPC 173 variable region gene. These observations suggest that somatic DNA rearrangement of immunoglobulin light chain genes can involve both homologous chromosomes.Images
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PMID:Cloning of immunoglobulin kappa light chain genes from mouse liver and myeloma MOPC 173. 11 75

Immunoglobulin kappa chain gene formation involves site-specific somatic recombination between one of several hundred germ-line variable region genes and a joining site (or "J segment") encoded close to the constant region gene. We have cloned and determined the nucleotide sequence of major portions of the recombination region of the mouse kappa gene and discovered a series of five such J segments spread out along a segment of DNA 2.4 kilobases from the kappa constant region gene. These J segments encode the 13 COOH-terminal amino acids of the variable region, probably including amino acids involved in the antigen combining site and in heavy/light chain contacts. The J segments also display striking sequence homology to one another in both their coding and immediately flanking sequences. Major elements of a short palindrome--CAC(TA)GTG--are preserved adjacent to the recombination sites of both variable and J region genes and constitute inverted repeats at both ends of the sequences to be joined. These palindromes can be written as a hypothetical stem structure that draws variable and J regions together, providing a possible molecular basis for the DNA joining event. Four of the J segments that we have discovered encode amino acid sequences already found in myeloma proteins. By altering the frame of recombination, we can account for additional light chain amino acid sequences, suggesting that the V/J joining event might generate antibody diversity somatically both by using different combinations of variable and J region genes and by using alternative joining frames.
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PMID:Sequences of five potential recombination sites encoded close to an immunoglobulin kappa constant region gene. 11

DNA from newborn mice was digested with restriction endonuclease EcoRI, and a 6.6-kilobase fragment encoding immunoglobulin gamma 2b chain mRNA derived from MPC 11 myeloma was enriched about 100-fold by RPC-5 column chromatography and agarose gell electrophoresis. The 6.6-kilobase fragment was cloned with lambda gt WES.lambda B as EK2 vector. The cloned phage (lambda WES.IgH22) contained the constant region gene of the gamma 2b chain but not the variable region gene of MPC 11 mRNA. The constant region genes of the other gamma chains (i.e., gamma 1, gamma 2a, and gamma 3) were not present in lambda gt WES.IgH22 DNA. R-loop mapping indicates that the gamma 2b chain structural gene is divided into two parts (330 +/- 60 SD base pairs and 930 +/- 110 SD base pairs) by an intervening sequence (360 +/- 100 SD base pairs). The nucleotide sequence around the junction of the hinge region and CH2 domain was determined and shown to match the amino acid sequence of the initial part of the CH2 domain of the gamma 2b chain. The base sequence upstream from the junction, however, is unrelated to the amino acid sequence of the CH1 domain and the hinge region of all the gamma chains whose sequences have been determined. These results indicate that the gamma 2b chain gene is interrupted at the junction of the hinge region and CH2 domain by an intervening sequence. The existence of two more intervening sequences, one between the CH1 domain and the hinge region and the other between the CH2 and CH3 domains, is discussed.
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PMID:Cloning immunoglobulin gamma 2b chain gene of mouse: characterization and partial sequence determination. 11 31

Analysis of the available DNA sequences of immunoglobulin light chain genes reveals a unique structural pattern. A stretch of about 15 nucleotides repeats five times within the variable (V) region gene, with few base changes. Identification of these homologous sequences is apparent in the embryonic V(lambda) gene and might also be recognized in V(kappa) genes isolated from a myeloma. Although different from each other, the V(lambda) and V(kappa) hyperhomologous sequences display a remarkable resemblance to different prokaryote sequences associated with recombinational events. The homologous sequences appear at all three sites where hypervariable regions of the mature peptide are encoded. In addition, they are located at the site where V/constant (C) recombination is supposed to take place. Consequently, a general model is proposed for immunoglobulin differentiation. The hyperhomologous loci are postulated to be comprised of recombination sequences which makes them available for a mechanism of single-stranded DNA exposure. B cell maturation begins with V/C recombination, a step that is rate limiting. The fidelity of the process is ensured by extensive DNA homology between the two embryonic subgenes of V and C. Next, an error-prone repair system is activated and thereby introduces changes into the content of the immunoglobulin gene at the exposed loci. The process ends when mutations make the recombination sequence unrecognizable as such. The model is consistent with large amounts of data and is compatible with the view that immunoglobulin diversity is being generated somatically.
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PMID:Immunoglobulin differentiation is dictated by repeated recombination sequences within the V region prototype gene: a hypothesis. 11 34

The MF2 strain, a mouse myeloma derived cell line, was found to induce the mixed culture cytopathogenicity test when cocultured with XC cells. Only one MF2 cell was present per syncytium, as shown by autoradiography. Pretreatment of cells with inhibitors of DNA, RNA or protein synthesis suggested that a normal RNA synthesis was required to obtain optimal polykaryon growth. Immunoelectron microscopy using a syngenic mouse MF2 cell antiserum and peroxydase labeling revealed a complete mixing and redistribution of the respective plasma membrane sites of MF2 and XC cells on polykaryon surface.
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PMID:XC-cell fusion induced by murine plasmocytoma cells. II. Cytological and ultrastructural study. 12 27

An ATPase was purified from mouse myeloma MOPC 70E the activity of which depends on the presence of single-stranded DNA and divalent cations such as Mg2+, Mn2+, Ca2+, Ni2+ or Fe2+. The enzyme splits both ribonucleoside and deoxyribonucleoside triphosphates but preferentially ATP and dATP yielding nucleoside diphosphates and inorganic phosphate. The enzyme has an absolute requirement for single-stranded DNA. Alternating double-stranded polydeoxynucleotides are only slight effective, and native double-stranded DNA, single-stranded and double-stranded RNAs as well as DNA - RNA hybrids are ineffective in stimulating the ATPase. The enzyme has further characterized by sedimentation in a sucrose density gradient (s20, w = 5.5 S) and by isoelectric focussing in an ampholine pH gradient (pI = 6.5).
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PMID:An ATPase depending on the presence of single-stranded DNA from mouse myeloma. 12 26

An Epstein-Barr virus (EBV)-negative lymphoblastoid cell line (LCL), BJA-B, was established from an African Burkitt's lymphoma (BL) which contained no detectable EBV DNA and did not express the EBV specified antigen EBNA, BJA-B cells grow in typically large, flat clumps. All carry surface-bound immunoglobulins, a B lymphocyte marker, and do not form rosettes with sheep erythrocytes. After infection of BJA-B cells by EBV the infected cells may produce either EBV-determined nuclear antigen (EBNA) or both EBNA and early antigen (EA), depending on the strain of EBV. The homogeneity of the BJA-B cell population with respect to immunological and isoenzyme markers and size suggests a clonal origin of the line. BJA-B is the first EBV-negative LCL established from an African Burkitt's lymphoma and demonstrates that an EBV-independent continuous B cell line can be established "in vitro" from other than leukemia or myeloma cells.
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PMID:Establishment and characterization of an Epstein-Barr virus (EBC)-negative lymphoblastoid B cell line (BJA-B) from an exceptional, EBV-genome-negative African Burkitt's lymphoma. 17 29

The MF2 strain, a mouse myeloma derived cell line, was found to continuously produce C-type viral particles when maintained in tissue-culture. These cells when cultured in an ascitic form by injection to Balb/c mice lost this property. The ability to induce syncytia by cocultivation of the MF2 cell with XC-cells was shown to be related to the viral production. A DNA complementary to viral 70 S RNA was synthesized using the viral reverse-transcriptase endogenous activity. The quality of the probe is discussed and the expression of the viral genome among cellular poly A rich RNA varied concomitently to the syncytium inducing ability as evidenced by molecular hybridization experiments.
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PMID:XC-cell fusion induced by murine plasmocytoma cell. III. RNA gene expression correlated to syncytium formation. 18 44

A [3H[cDNA probe synthesized from the RNA genome of Rauscher murine leukemia virus (MuLVR) and purified by hybridization to MuLVR70S RNA was hybridized to DNA from human normal and hemotopoietic neoplasia tissues. This cDNA hybridized completely to its homologous 70S RNA and was free of self-complementary sequences. Sequences complementary to MuLVR cDNA were found in DNA from tissues of some patients with leukemia (2 of 8), Hodgkin's disease (3 of 10), and one patient with multiple myeloma. DNA from spleen and kidney of a patient with nonneoplastic disease did not contain detectable MuLVR-related sequences. These virus-related sequences in the DNA from these neoplastic tissues were related but not identical to MuLVR sequences because differences of approximately 6 degrees in the midpoints of thermal elution profiles were found between the heterologous and homologous duplexes. These nucleotide sequences are not the same as the proviral sequences of baboon type-C virus previously found from some other patients with leukemia [Reitz et al. (1976) Proc. Natl. Acad. Sci. USA 73,2113-2117; Wong-Staal et al. (1976) Nature 262, 190-195], because there is no sequence homology between nucleic acids from MuLVR and baboon virus. The absence of these nucleic acid sequences in many tissues of patients with neoplasia and from the few tissues examined from people with nonneoplastic disease suggests that they are not endogenous elements but are acquired after fertilization. Taken together with the previous detection of baboon and woolly monkey type-C viral related components in some human tumors, the results suggest acquisition of at least three types of type-C viral sequences in the human population.
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PMID:Rauscher-leukemia-virus-related sequences in human DNA: presence in some tissues of some patients with hemotopoietic neoplasias and absence in DNA from other tissues. 18 12


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