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)

A series of mouse myeloma cell lines producing mutant gamma 2b immunoglobin heavy chains, which resemble heavy chain disease proteins, were analyzed for messenger RNA abundance as a function of mRNA alterations. A mutation effectively deleting the gamma 2b-CH1 domain of the mRNA had little or no effect on Ig heavy chain mRNA abundance on half-life (mutant 10.1). A mutation in the gamma 2b-CH2 and CH3 domain, causing premature termination of translation, had more deleterious effects on Ig heavy chain mRNA abundance and half-life (mutant I17). Substitution of the deleted portions of the gamma 2b mRNA with gamma 2a sequences by subclass switching in the cells (mutants K23 and K25) resulted in increased heavy chain abundance and half-life relative to the parent I17. In contrast, kappa light chain mRNA levels and half-lives remain constant among the mutants. The wild-type and mutant cell lines transcribed the Ig heavy chain gamma 2b locus equally when compared with an internal beta-actin standard by transcription run on studies. Therefore, half-life of the Ig heavy chain mRNA seems to be the principal determinant in cytoplasmic mRNA abundance in this system.
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PMID:Differential mRNA stabilities affect mRNA levels in mutant mouse myeloma cells. 190 Jan 33

The complementarity determining region III of the rearranged immunoglobulin heavy chain gene has been the target for tumor-specific PCR assays for the detection and follow-up of B-cell malignancies. Previously, these assays have relied on gel-based end point data collection methods (i.e., band densitometry) and, thus, have provided at best a semiquantitative assessment of tumor levels. We show the development of a novel, real-time TaqMan PCR assay to quantitate residual multiple myeloma cells in clinical samples after high-dose chemotherapy and autologous stem cell transplantation. We provide evidence that real-time PCR is reproducible, sensitive, and quantitative. In a 40-replicate PCR experiment targeting the beta-actin gene, the coefficient of variation for threshold cycle data was 1.6%, whereas it increased to 13.6% and 31%, respectively, for end point fluorescence and gel densitometry. Moreover, in an experiment directly comparing standard curves obtained from band densitometry and threshold cycle data, the standard curve constructed from threshold cycle data had a multiple R2 value of 1.00 and demonstrated a dynamic range >4 logs, compared with the 2-log linear range of gel densitometry. Finally, we show that when a complementarity determining region III-specific PCR primer is used in conjunction with a consensus primer for the immunoglobulin heavy chain joining gene, plasmid DNA can be used as a readily available and effective substitute for clonal plasma-cell genomic DNA when preparing standards. By applying real-time PCR to the analysis of clinical samples, we are able to quantitate levels of tumor involvement with unparalleled reproducibility and statistical confidence. Real-time PCR technology may well provide the accuracy and reliability necessary for minimal residual disease detection to have real prognostic significance.
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PMID:Improved quantitation of minimal residual disease in multiple myeloma using real-time polymerase chain reaction and plasmid-DNA complementarity determining region III standards. 973 9

Interleukin-6 (IL-6) is implicated in the in vivo proliferation of malignant plasma cells in multiple myeloma. To define the molecular basis of the IL-6-induced mitogenic response in myeloma cells, we applied STAR (subtractive transcriptional amplification of mRNA), a new differential expression analysis technology, to isolate mRNAs preferentially expressed in IL-6-treated versus untreated cultures of the factor-responsive myeloma cell line U266. From the resulting collection of STAR clones, sequence information was obtained for a total of 72 distinct transcripts. Of these, 29 were found to correspond to known genes, 22 matched expressed sequence tags in public databases and 21 showed no sequence similarity to any existing entries. Among the known genes uncovered in the screen were those encoding proteins that function in cell division, cell signalling and gene/protein expression. Northern blot analysis documented that two transcription factor genes chosen for further study, c-myc promoter-binding protein (MBP-1) and X-box binding protein 1 (XBP-1), were up-regulated in U266 cells about 3-fold relative to the cell cycle-dependent beta-actin gene 12 h after IL-6 treatment. Both genes were also similarly up-regulated by IL-6 in factor-dependent ANBL-6 myeloma cells. These results indicate that MBP-1 and XBP-1 are IL-6 genes in myeloma cells; as such, they may play a role in IL-6-mediated growth control in multiple myeloma.
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PMID:Identification of c-myc promoter-binding protein and X-box binding protein 1 as interleukin-6 target genes in human multiple myeloma cells. 1037 12

We investigated mismatch repair (MMR) gene expression in 31 lymphoid tissue specimens and bone marrow aspirates with malignant lymphoproliferative disorders of B-cell origin (25 cases of lymphoma and six cases of plasma cell myeloma). A multiplex RT-PCR assay was employed to assess the relative expression of the hMSH2, hMLH1 and hPMS1 genes, as compared to beta-actin, which was used as an internal control of gene expression. MSH2 was further evaluated at the protein level by immunohistochemistry. The findings were compared to those of a control group of lymphoid tissue specimens without evidence of malignancy (n = 6). Changes in MMR gene expression were observed in 10 out of 31 cases of the study group (32%). All three MMR gene transcripts were low in two out of six plasma cell myelomas, which had extensive bone marrow infiltration by neoplastic cells. The hMSH2 transcript was present in all cases of lymphoma, while the expression of hMLH1 and hPMS1 was significantly low in some large B-cell lymphomas (four and five out of 14 cases, respectively) and in mantle cell lymphomas of the blastoid type (two out of two cases). No MMR gene aberrations were found in seven cases of B-cell lymphocytic leukemia and two cases of mantle cell lymphoma of centrocyte-like type. These findings demonstrate that the expression rates of the hMSH2, hMLH1 and hPMS1 genes differ among various types of B-cell lymphoproliferative disorders, and suggest that MMR gene expression may be related to the natural history of these neoplasms. This study identified a higher incidence of MMR gene aberrations in lymphoma types characterized by aggressive biologic behavior, as compared to neoplasms with a more indolent course.
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PMID:Mismatch repair gene expression in malignant lymphoproliferative disorders of B-cell origin. 1199 75

Mouse myeloma NS0 cells widely used in hybridoma technology lack the expression of a major stress protein Hsp70 which is the principal component of the basic cellular defense mechanism. These cells rapidly undergo apoptosis at the late-stationary phase of batch culture following nutrient exhaustion. Since Hsp70 was recently demonstrated to protect cells against numerous apoptotic stimuli, the aim of the present study was to examine the protective potential of the protein expression in engineered myeloma NS0 cells and in resulting hybridomas. Myeloma cells were transfected with the hsp70 gene under beta-actin gene promoter. To imitate harmful conditions that hybridoma or myeloma cells often experience when cultivated in large scale for an antibody production, NS0(wt) and NS0(hsp70) cell cultures were maintained without changing the medium for a few days, and the expression of apoptotic markers has been studied. It was found that long-term cultivation induced apoptosis in original cells manifested by typical nuclei fragmentation, DNA ladders and activation of caspase-3. In contrast, in transfected cells under the same conditions the outcome of apoptosis was postponed for 24 hours. Most relevant was that the fusion of transfected myeloma cells with immune splenocytes resulted in twofold hybridomas output compared with wild-type fusion partner. Almost half of the hybridomas continued to be hsp70-positive and maintained higher robustness in culture. The level of monoclonal antibodies production by hybridoma cells obtained with the use of NS0(wt) and NS0(hsp70) was similar, however, the secreted product was better preserved in culture supernatants of Hsp70-positive cells. It is concluded that transfection of mouse myeloma cells with the hsp70 gene can be a novel means to increase hybridoma yield and reduce the sensitivity of myeloma and hybridoma cells to culture conditions insults accompanying monoclonal antibody production.
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PMID:Transfection of NS0 myeloma fusion partner cells with HSP70 gene results in higher hybridoma yield by improving cellular resistance to apoptosis. 1249 34

We have established a large-scale manufacturing system to produce recombinant human alpha-thrombin. In this system, a high yield of alpha-thrombin is prepared from prethrombin-2 activated by recombinant ecarin. We produced human prethrombin-2 using mouse myeloma cells and an expression plasmid carrying the chicken beta-actin promoter and mutant dihydrofolate reductase gene for gene amplification. To increase prethrombin-2 expression further, we performed fed-batch cultivation with the addition of vegetable peptone in 50 liters of suspension culture. After five feedings of vegetable peptone, the expression level of the recombinant prethrombin-2 reached 200 micro g/ml. Subsequently, the recombinant prethrombin-2 could be activated to alpha-thrombin by recombinant ecarin expressed in a similar manner. Finally, recombinant alpha-thrombin was purified to homogeneity by affinity chromatography using a benzamidine-Sepharose gel. The yield from prethrombin-2 in culture medium was approximately 70%. The activity of the purified recombinant alpha-thrombin, including hydrolysis of a chromogenic substrate, release of fibrinopeptide A, and activation of protein C, was indistinguishable from that of plasma-derived alpha-thrombin. Our system is suitable for the large-scale production of recombinant alpha-thrombin, which can be used in place of clinically available alpha-thrombin derived from human or bovine plasma.
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PMID:Preparation of recombinant alpha-thrombin: high-level expression of recombinant human prethrombin-2 and its activation by recombinant ecarin. 1517 95

The study was purposed to investigate the effect of arsenic trioxide (As(2)O(3))- induced p16 gene demethylation by a sensitive and specific PCR-based method (nested-methylation specific PCR, n-MSP) and DNA sequencing for rapid analysis of the promoter demethylation status, and to explore the possible mechanism of the p16 gene demethylation in human multiple myeloma U266 cells induced by As(2)O(3). The methylation status of the p16 gene in U266 cell line before and after treatment with As(2)O(3) was detected by the nested-methylation specific PCR and DNA sequencing, the mRNA of p16, DNA methyltransferase (DNMT 1, DNMT3A and 3B) gene were determined by RT-PCR, and the induced growth inhibition of U266 cell was assayed by growth curve, MTT and CFU; the DNA content of U266 cells was analyzed by flow cytometry after being exposed to As(2)O(3). The results showed that (1) all cytosines in CpG dinucleotides in untreated U266 cell not were changed, while all cytosines in treated U266 cells with As(2)O(3) had been converted to thymidine. (2) p16 gene was not expressed in U266 cell line after methylation. As compared with the beta-actin, the expression of U266 cell p16 gene mRNA was increased to (0.22 +/- 0.10), (0.59 +/- 0.11), (0.68 +/- 0.09) after exposed to 0.5 micromol/L, 1.0 micromol/L and 2.0 micromol/L As(2)O(3) for 72 hours respectively. (3) As(2)O(3) could significantly down-regulate DNA methyltransferase 1 (DNMT 1), DNMT3A and DNMT3B gene at mRNA level in a dose-dependent manner. (4) U266 cells line grew slowly and arrested at G(0) - G(1) phase after treatment with three different concentrations of As(2)O(3). It is concluded that As(2)O(3) can activate and up-regulate the expression of p16 gene which inhibits the proliferation of U266 cell through inducing the G(0) - G(1) arrest by demethylation or/and by inhibiting DNMT 1, DNMT3A and 3B gene.
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PMID:[n-MSP detection of p16 gene demethylation and transcription in human multiple myeloma U266 cell line induced by arsenic trioxide]. 1749 May 27