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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oncornavirus-like particles of the "A" (both intracisternal and intracytoplasmic) and "B" or "C" (extracellular) types are produced by murine MOPC-460 myeloma cells. This communication describes a comparative study on tracisternal A and extracellular particles. Both types of particles contain an RNA-dependent DNA polymerase activity, traces of 35S and 70 S RNA in addition to larger amounts of degraded RNA, and proteins of approximately 76,000 and 45, 000 daltons. The 76,000-dalton proteins from intracisternal A and extracellular particles have the same cyanogen bromide peptides. Hybridization kinetic analysis indicates that the RNAs in the two particles are identical or very closely related and share partial homology with Moloney leukemia virus RNA. In contrast, the particles appear to have little or no relationship to murine mammary tumor virus as judged by several different criteria. Electron microscope studies indicate that the extracellular particles arise from the budding of core components through the plasma membrane. These results suggest that the intracisternal A and extracellular oncornavirus-like particles produced by MOPC-460 cells are closely related.
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PMID:Relationships between intracisternal type A and extracellular oncornavirus-like particles produced in murine MOPC-460 myeloma cells. 5 64

Intracisternal A particles (IAPs) are retrovirus-like structures consistently observable in a variety of mouse tumor cells such as myeloma and hybridoma and in early embryonic cells derived from rodents but nothing is known of their infectivity. Mouse IAPs contain a gag-like protein, a reverse transcriptase and a polyadenylated RNA molecule (IAP RNA). DNA sequences complementary to IAP RNA (IAP genome) are interspersedly present in rodent such as mice, rats, Chinese hamsters and Syrian hamsters at several hundred to a thousand copies per haploid genome. Molecularly cloned IAP genomes from two species Mus and Syrian hamster were 6 to 8 kb in length with LTRs of about 0.4 kb long. The nucleotide sequence of the Syrian hamster IAP genome, H18, predicted a typical LTR-gag-prt-pol-env-LTR structure, although many stop codons were present in the region corresponding to env. The comparison of the deduced amino acid sequences of the pol region showed IAP (type A), mouse mammary tumor virus (MMTV) (type B), and squirrel monkey retrovirus (SMRV) (type D) genomes to be closely related. By using a DNA fragment encoding the pol region of the Syrian hamster IAP genome, human endogenous retroviruses termed HERV-K, were cloned from a fetal human liver gene library. Typical HERV-K genome was 9.5 kb in length having LTRs of about 1.0 kb. The HERV-K provirus could encode gag (666 codons), prt (334 codons), pol (937 codons), and env (618 codons) genes. HERV-K was shown to be closely related to types A, B and D retroviruses. The HERV-K genomes are present at about 50 copies per haploid human genome. In several human tumor cell lines, the HERV-K genome was expressed as 8.8 kb poly(A)+ RNA which appeared to be a full-size transcript of this genome. In the human breast cancer cell line T47D, stimulation of HERV-K genome expression was observed following female steroids treatment. In a detailed investigation on the organization of HERV-K proviruses in human genome, we found repetitive sequences homologous to the LTR region of the HERV-K genome. They were about 630 bp in length with an A rich tail at 3' end and found to be a SINE type nonviral retroposon. These elements were present at 4,000 to 5,000 copies per haploid human genome.
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PMID:Molecular biology of type A endogenous retrovirus. 171 Jun 82

M cells of intestinal epithelia overlying lymphoid follicles endocytose luminal macromolecules and microorganisms and deliver them to underlying lymphoid tissue. The effect of luminal secretory IgA antibodies on adherence and transepithelial transport of antigens and microorganisms by M cells is unknown. We have studied the interaction of monoclonal IgA antibodies directed against specific enteric viruses, or the hapten trinitrophenyl (TNP), with M cells. To produce monospecific IgA antibodies against mouse mammary tumor virus (MMTV) and reovirus type 1, Peyer's patch cells from mucosally immunized mice were fused with myeloma cells, generating hybridomas that secreted virus-specific IgA antibodies in monomeric and polymeric forms. One of two anti-MMTV IgA antibodies specifically bound the viral surface glycoprotein gp52, and 3 of 10 antireovirus IgA antibodies immunoprecipitated sigma 3 and mu lc surface proteins. 35S-labeled IgA antibodies injected intravenously into rats were recovered in bile as higher molecular weight species, suggesting that secretory component had been added on passage through the liver. Radiolabeled or colloidal gold-conjugated mouse IgA was injected into mouse, rat, and rabbit intestinal loops containing Peyer's patches. Light microscopic autoradiography and EM showed that all IgA antibodies (antivirus or anti-TNP) bound to M cell luminal membranes and were transported in vesicles across M cells. IgA-gold binding was inhibited by excess unlabeled IgA, indicating that binding was specific. IgG-gold also adhered to M cells and excess unlabeled IgG inhibited IgA-gold binding; thus binding was not isotype-specific. Immune complexes consisting of monoclonal anti-TNP IgA and TNP-ferritin adhered selectively to M cell membranes, while TNP-ferritin alone did not. These results suggest that selective adherence of luminal antibody to M cells may facilitate delivery of virus-antibody complexes to mucosal lymphoid tissue, enhancing subsequent secretory immune responses or facilitating viral invasion.
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PMID:Binding and transepithelial transport of immunoglobulins by intestinal M cells: demonstration using monoclonal IgA antibodies against enteric viral proteins. 254 Nov 37

Mouse cell lines of different lineages have been established which constitutively secrete large quantities of recombinant mouse interleukins (mIL2, mIL3, mIL4 or mIL5). An existing bovine papilloma virus-based expression vector, pBV-1MTHA, was modified to allow transformed X63Ag8-653 myeloma cells, NIH 3T3 fibroblasts and C127 mammary tumor cells to stably carry multiple copies of the vector, to express the inserted cDNA encoding a single interleukin constitutively, and to secrete the interleukin in high quantities. Cell lines transformed with mIL2 cDNA stably carried 30-100 copies of the plasmid per cell and constitutively secreted biologically active mIL2 in quantities similar to those produced by murine EL4 thymoma cells or rat spleen cells stimulated with mitogens. Deletion of the 3' untranslated region containing AT-rich sequences from the mIL2 cDNA resulted in a 100-fold increase in the constitutive production and secretion of mIL2 by the transformants. Addition of a heavy metal further increased the production 2 to 6-fold. Cells transformed with 3'-deleted mIL3 cDNA constitutively secreted 300-1000 times higher activities of mIL3 than the myelomonocytic leukemia line WEHI3. mIL4 produced by the similar transformants induced [3H]thymidine uptake of a T cell line, a mast cell line and B leukemia cells, and enhanced the production of IgG1 by B cells. IL4 titers were 150 times higher than those produced by the concanavalin A-stimulated T cell line 2.19. mIL5 was secreted by similar transformants at 10-fold higher titers than those produced by concanavalin A-stimulated 2.19 T cells, as judged by the proliferation and maturation of B cell leukemia BCL1. The expression vectors should be useful in establishing eukaryotic cell lines producing proteins from full length cDNA clones at higher rates. The established cell lines secreting IL2, 3, 4 or 5 at high rate should be useful sources for these interleukins in the investigation of their function in the immune system.
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PMID:Establishment of mouse cell lines which constitutively secrete large quantities of interleukin 2, 3, 4 or 5, using modified cDNA expression vectors. 283 Oct 66

Among 41,109 women diagnosed with breast cancer between 1935 and 1982 in Connecticut, 3,984 developed a second cancer, whereas 2,426 were expected [relative risk (RR) = 1.64; 95% CI = 1.6-1.7]. This increased risk persisted for 30 years and was highest in women under 55 years of age at the time of breast cancer diagnosis. Second primary breast cancers (RR = 3.0) accounted for almost one-half of all new neoplasms. However, if subsequent breast cancers were excluded, the risk for all other second cancers was only 1.15 (95% CI = 1.10-1.20), and no excess risk was seen among women over age 55 at initial breast cancer. Significant risks were found for cancers of the ovary (RR = 1.7) and uterine corpus (RR = 1.4), possibly linked with shared reproductive factors such as nulliparity or late age at menopause. Malignant melanoma (RR = 1.5), thyroid cancer (RR = 1.6), and colon cancer (RR = 1.2) were also significantly elevated; possible shared risk factors remain to be elucidated. Significant deficits of multiple myeloma and chronic lymphocytic leukemia were noted. Women who received initial radiotherapy compared with those who did not were at slightly higher risk of developing a second cancer, most notably acute nonlymphocytic leukemia, non-Hodgkin's lymphoma, and cancers of the esophagus, kidney, and connective tissue, although the nature of the associations was not always clear. Some of the soft tissue sarcomas were lymphangiosarcomas of the arm, a consequence of the lymphedema that may complicate radical mastectomy (Stewart-Treves syndrome). Women treated with radiation were at higher risk of developing a second breast neoplasm (RR = 3.9) than nonirradiated women (RR = 2.8). Further investigation should focus on the mechanisms underlying the relationships between breast, genital tract, and colon cancers, and on the effects of treatment modalities on the risk of subsequent neoplasms.
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PMID:Second cancer following cancer of the breast in Connecticut, 1935-82. 408 15

Intracisternal A-particles were isolated from three different myeloma lines in BALB/c mice and from cultured neuroblastoma cells of A/J origin. All preparations contained a major structural protein with an apparent molecular weight near 70,000 as estimated by electrophoretic mobility in sodium dodecyl sulfate-containing polyacrylamide gels. Solubilization of this component by sodium dodecyl sulfate was dependent on prior or concomitant treatment with sulfhydryl compounds. The size distribution of A-particle proteins was markedly different from that observed for extracellular murine leukemia and mammary tumor viruses. Rabbit antiserum was developed that reacted with the major A-particle protein in both complement fixation and immunodiffusion assays. The antigen was detected in isolated neuroblastoma A-particles, in cytoplasmic membrane fractions prepared from various mouse tumors known to contain intracisternal particles, but not in preparations from normal mouse cells, in samples of leukemia and mammary tumor virus, or in JLS-V9 cells infected with Rauscher leukemia virus. Conversely, isolated A-particles did not react in complement fixation or immunodiffusion assays with antisera against leukemia virus antigens.
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PMID:Some structural and antigenic properties of intracisternal A particles occurring in mouse tumors (complement fixation-immunodiffusion-neuroblastoma-plasma-cell tumor). 433 40

Hybrid cell lines producing monoclonal antibodies against the C3H strain of mouse mammary tumor virus (C3H MMTV) were prepared by the fusion of mouse myeloma cells with the lymphocytes of BALB/c mice that were immunized with C3H MMTV. Approximately 10% of the hybrid cells initially plated after cell fusion produced immunoglobulins that reacted in antibody-binding assays with C3H MMTV; 40 of these cells were cloned, and 6 eventually yielded stable cell lines. High concentrations of monoclonal antibodies (5 to 20 mg/ml) were obtained from serum and ascites fluid of syngeneic mice inoculated with the hybrid cells. All of the monoclonal antibodies were directed against the envelope glycoprotein gp52. Three of the hybrid cell lines produced immunoglobulins of the immunoglobulin M subclass and three produced immunoglobulin G2a. The monoclonal antibodies showed limited charge heterogeneity in light and heavy chains when analyzed by high-resolution, two-dimensional gel electrophoresis. Three serologically distinct specificities were observed when these ascites fluids were tested against different strains of MMTV. The antigenic determinants detected were the following: (i) a type-specific determinant unique to the C3H strain of MMTV; (ii) class-specific determinants shared between C3H and GR MMTVs; and (iii) a group-specific determinant found on C3H, GR, RIII, and the endogenous C3H (C3Hf) MMTVs. Because monoclonal antibodies recognize single antigenic determinants, these results demonstrate for the first time that the three patterns of antigenic reactivity for MMTV are related to individual determinants on the gp52 molecule and also clearly show that one strain of MMTV can be distinguished from other strains.
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PMID:Monoclonal antibodies identify individual determinants on mouse mammary tumor virus glycoprotein gp52 with group, class, or type specificity. 615 75

We have produced lymphocyte hybridomas between mouse myeloma cells and either spleen cells of C3H/f/C57BL/6 mice bearing the Mm5mt/c1 tumor-producing murine mammary tumor virus (MMTV) or spleen cells from Fisher rats inoculated with the same tumor. Two classes of hybridoma-secreted monoclonal antibodies were obtained. In the first class are IVC11, IIIA1, and VE7, each of which precipitated a 52,000-dalton protein from 125I-labeled purified preparations of MMTV and [3H]glucosamine-labeled Mm5mt/c1 cell extracts. A second class of monoclonal antibodies, represented by IC12 and IIIB5, reacted specifically with C3H MMTV-secreting cells in radioimmunoassays (RIA) with whole cells and did not precipitate proteins with labeled virus or metabolically labeled Mm5mt/c cell extracts. IC12 and IIB5 could be distinguished from each other in a RIA in which antigen discs were prepared from a membrane preparation of Mm5mt/c1 cells. In this assay, IC12 antibody was blocked from reacting with discs precoated with goat anti-MMTV, and IIB5 antibody was not.
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PMID:Monoclonal antibodies against antigens displayed on a progressively growing mammary tumor. 626 47

The expression of tumor-associated antigens on the DBA/2 lymphoma L1210 and three L1210 sublines, each resistant to a different antileukemic agent [guanazole, methylglyoxal-bis(guanylhydrazone), and 4,4-diacetyldiphenylurea-bis(guanylhydrazone)] was investigated by the use of monoclonal hybridoma antibodies. Hybridomas were produced by the fusion of spleen cells from DBA/2 mice immunized with irradiated L1210 or L1210 subline cells and cells of a non-immunoglobulin-secreting BALB/c myeloma variant. Three clones producing antibodies reacting with L1210 or L1210 subline cells were used to study the antigenic expression of L1210 and L1210 subline cells. Monoclonal antibodies from anti-L1210 and anti-L1210 subline hybridomas exhibited a greater reactivity with L1210 subline cells than with L1210 cells in complement-dependent cytotoxicity, quantitative absorption, and membrane immunofluorescence experiments, thereby demonstrating a tumor-associated antigen shared by L1210 and the L1210 sublines and an increased expression of this antigen on subline cells. Cross-blocking tests of antibody binding demonstrated that monoclonal antibodies from anti-L1210 and anti-L1210 subline hybridomas recognized the same or very closely situated antigenic determinants on the tumor cell surface. Most syngeneic and allogeneic tumor cells used as controls failed to react with the anti-L1210 and anti-L1210 subline hybridoma antibodies. However, two syngeneic tumors, L5178Y and P388-D1, demonstrated a significant reaction with the monoclonal antibodies. In addition, several spontaneous mammary tumors from C3H/St and DBA/2Ha, both high-frequency mammary tumor strains, reacted in various degrees with anti-L1210 or anti-L1210 subline hybridoma antibodies in absorption tests and in immunofluorescence experiments. On the other hand, liver, kidney, and spleen from normal C3H/St mice, as well as mammary tumors from BALB/c and C3Hf, both low-frequency mammary tumor strains, did not demonstrate significant reactivity in similar experiments. Normal lactating mammary glands from high-frequency mammary tumor mouse strains reacted with the monoclonal antibodies, whereas lactating mammary glands from low-frequency mammary tumor mouse strains were negative by this method. Purified murine mammary tumor virus preparations reacted strongly with the monoclonal antibodies in solid-phase radioimmunoassays, whereas a purified murine leukemia virus preparation failed to do so in similar experiments. These results indicate that the tumor-associated antigen(s), differentially expressed on L1210 and L1210 subline cells, is related to an antigen which is associated with the murine mammary tumor virus.
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PMID:Differential antigenic expression of the DBA/2 lymphoma L1210 and its sublines: cross-reactivity with C3H mammary tumors as defined by syngeneic monoclonal antibodies. 634 55

Splenic lymphocytes of mice immunized with membrane enriched fractions of human mammary carcinomas were fused with the NS-1 nonsecretory++ myeloma cell line. The resulting hybridomas were screened for the synthesis of immunoglobulins reactive with human mammary tumor associated antigens, and two IgG monoclonal antibodies (B1.1 and F5.5) were identified as being reactive with purified carcinoembryonic antigen (CEA). These antibodies were shown to bind to different epitopes on CEA based on their differential reactivities to five different purified CEA preparations, and their differential binding to the surface of tumor cells derived from various organ sites. Monoclonal B1.1 bound equally to the surface of human breast, colon, and melanoma cell lines. Monoclonal F5.5, on the other hand, did not react with the surface of melanoma cell lines, and showed a differential binding to breast carcinoma versus colon carcinoma cells. Monoclonals F5.5 and B1.1 were both used in immunoperoxidase studies with fixed tissue sections of a variety of histologic types of human mammary carcinomas and were shown to be reactive with 55% and 66%, respectively, of tumor masses.
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PMID:Differential binding to human mammary and nonmammary tumors of monoclonal antibodies reactive with carcinoembryonic antigen. 636 68


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