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 previously isolated and sequenced the 5'-flanking region of the mouse CD14 (mCD14) gene (Matsuura, K., Setoguchi, M., Nasu, N., Higuchi, Y., Yoshida, S., Akizuki, S., and Yamamoto, S. (1989) Nucleic Acids Res. 17, 2132). To define the regulatory elements that control expression of the mCD14 gene, we analyzed the structure of the 5' end of the gene, including a region further upstream of that determined previously. Sequentially 5'-deleted, chimeric, and point mutated clones were tested for the ability to stimulate chloramphenicol acetyltransferase. An 8-base pair sequence, TGATTCAC, at position -255, which resembled the consensus sequence of the 12-O-tetradecanoylphorbol-13-acetate-responsive element (TRE), enhanced the expression of the chloramphenicol acetyltransferase gene in macrophage (aHINS-B3) and non-macrophage (glioblastoma G203 and myeloma NS1) cells. The enhancing ability of the TRE-like sequence (TLS), however, was markedly reduced in G203 cells but not in aHINS-B3 cells when the TLS was followed by the sequence immediately downstream. The TLS and sequence immediately downstream were capable of binding nuclear proteins which were unique to aHINS-B3 cells and macrophages, suggesting that these unique protein regulate the specific expression of the mCD14 gene. Binding of AP-1 to the TLS was also found in aHINS-B3 and G203 cells. Although it is uncertain whether AP-1 is involved in expression of the mCD14 gene, the effect of AP-1 in non-macrophage cells was inhibited by a nuclear protein which binds to the sequence immediately downstream of the TLS.
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PMID:Identification of a tissue-specific regulatory element within the murine CD14 gene. 138 28

We sought to determine the cis-acting elements responsible for the pattern of tissue specific expression of the mouse alpha 2(I) collagen gene. Using an RNase protection assay we first verified that expression of the alpha 2(I) collagen gene is mainly confined to tendons, bone, and skin in mice. Both transgenic mice and DNA transfection of tissue culture cells were used as experimental approaches. Transgenic mice lines were generated harboring chloramphenicol acetyltransferase (CAT) chimeric genes that contained either (a) 2000 base pairs (bp) of 5'-flanking sequences of the mouse alpha 2(I) collagen gene plus additional sequences between +418 and +1524 of the first intron of this gene or (b) the same promoter sequences without intron sequences or (c) the 350-bp proximal promoter sequences. Transgenic mice containing both types of 2000-bp promoters showed a pattern of CAT expression that was tissue specific. The presence of sequences of the first intron in the transgene did not increase the level of promoter activity. Transgenic mice harboring the 350-bp alpha 2(I) collagen promoter also showed a pattern that was tissue-specific except that high level expression also occurred in the brain. This suggests that negative regulation is an important component of tissue-specific expression. In order to analyze the first 350 bases in detail, we performed transient expression experiments, using promoter fragments attached to the luciferase reporter gene. Fibroblasts, which show a high level expression of the endogenous alpha 2(I) collagen gene, and B cells, in which the gene is silent, were transfected with a series of deletions and substitution mutations within the proximal 350-bp promoter. These experiments were unable to define unique cell-specific cis-acting elements. However, when the sequence between -315 and -284 was tandemly repeated upstream of a minimal alpha 2(I) collagen promoter (-41 to +54), the activity of this construction was considerably higher in fibroblasts than in B cells when compared with the minimal promoter itself. In gel retardation assays, the levels of complexes that bind to this sequence were higher in fibroblast nuclear extracts than in myeloma nuclear extracts. Our results are consistent with the hypothesis that the -315 to -284 DNA sequence participates in the cell-specific control of the alpha 2(I) collagen gene in fibroblasts.
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PMID:Tissue-specific expression of the mouse alpha 2(I) collagen promoter. Studies in transgenic mice and in tissue culture cells. 152 81

The immunoglobulin heavy-chain enhancer is a cis-acting element which activates transcription of nearby genes only in cells of the lymphoid lineage. To identify the minimal sequences necessary to impart cell type transcriptional specificity, we tested the activity of several deletions and internal mutations in the mu enhancer. Experiments involving measurement of both chloramphenicol acetyltransferase activity and RNA levels indicated the presence of a dominant repressor element within the mu enhancer. This repressive activity was detected in fibroblasts but not in myeloma cells. Removal or disruption of this repressor element revealed the presence of elements within the mu enhancer that activate transcription in fibroblasts. Thus, enhancer tissue specificity is in part due to the composite of both constitutive activation and cell-type-specific repressive activity. The possible biological roles of this phenomenon are discussed.
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PMID:Localization of a repressive sequence contributing to B-cell specificity in the immunoglobulin heavy-chain enhancer. 283 47

It has been shown recently that the c-mos oncogene becomes activated in myeloma XRPC-24 via insertion of an intracisternal A particle (IAP) long terminal repeat (LTR). The inserted LTR serves as a promoter from which transcription of the 3' rearranged c-mos initiates. The insertion is in a head-to-head orientation such that the transcriptional orientations of the IAP and the 3' rearranged c-mos are opposite. It has already been shown that this IAP LTR has two promoters, one transcribing the IAP genome and the other transcribing the rearranged c-mos. Since the IAP genomes are actively transcribed in mouse myelomas but not in normal cells, it was interesting to test whether transcriptional activation of the IAP occurs in the presence of active oncogene products, especially nuclear ones. The 5' LTR of the IAP inserted in myeloma XRPC-24 was chosen as a convenient model to test the effect of viral and cellular oncogene products. These included simian virus 40 (SV40) large-T antigen, the adenovirus early 1A (E1A) gene product, the myc gene product, and p53. The LTR was coupled to the bacterial gene coding for chloramphenicol acetyltransferase (CAT) in two orientations, and the levels of CAT directed by the LTR promoters were assayed in either the presence or the absence of the oncogene products. The levels of CAT directed by the 5' LTR promoter transcribing the IAP were significantly elevated in the presence of SV40 large-T antigen, the adenovirus E1A and myc gene products, and p53. The promoter transcribing the rearranged c-mos was transactivated by SV40 large-T antigen and the adenovirus E1A gene product. The results indicate that oncogene products may have an important role in turning on promoters of other genes. The IAP LTR may serve as a useful model for studying the effect of various gene products on promoters which are known to be activated in the malignant state.
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PMID:The long terminal repeat of the intracisternal A particle as a target for transactivation by oncogene products. 293 1

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

A chimeric gene was constructed in which sequences between 2,000 base pairs upstream of the start of transcription of the mouse alpha 2(I) collagen gene and 54 base pairs downstream of this site were fused to the chloramphenicol acetyltransferase (CAT) gene. We present evidence suggesting that this collagen gene segment is sufficient for cell-specific expression of the chimeric gene. Indeed, the levels of CAT activity in transient expression experiments were at least 10 times higher after transfection of NIH 3T3 cells than after transfection of a mouse myeloma cell line, whereas much less difference was found after transfection of these two cell types with pSV2-CAT, a plasmid in which the early simian virus 40 promoter is fused to the CAT gene. Several deletions were introduced in the same 5'-flanking segment of the alpha 2(I) collagen gene, and the effects of these deletions were examined after DNA transfection of the chimeric collagen-CAT gene into NIH 3T3 cells. At least two segments broadly located between -979 and -502 and between -346 and -104 are needed for optimal expression of the chimeric gene. These results were obtained both in transient expression experiments and by analysis of pools of NIH 3T3 cells that were stably transfected with the different mutants. In general, the effects of the deletions on the activity of the alpha 2(I) collagen promoter were analogous, whether the plasmids harbored the simian virus 40 enhancer sequence or not, although the overall levels of expression of the chimeric gene were increased when the recombinant plasmids contained this sequence.
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PMID:Transcriptional control of the mouse alpha 2(I) collagen gene: functional deletion analysis of the promoter and evidence for cell-specific expression. 378 51

In the mouse myeloma XRPC-24 the DNA of an intracisternal A-particle (IAP) is inserted within the coding region of c-mos. This insertion splits the c-mos into a 3' rc-mos and a 5' rc-mos separated by approximately 4.7 kb of IAP DNA. The insertion is in a head-to-head orientation and brings the 5' LTR of the IAP in juxtaposition to the 3' rc-mos such that the IAP and the 3' rc-mos are transcribed in opposite directions. The intact c-mos gene is usually dormant, whereas the 3' rc-mos is actively transcribed and is capable of transforming NIH3T3 cells. In an effort to understand the nature of this activation we mapped the 5' ends of the 3' rc-mos mRNA present in XPRC-24. We found two main mRNA start sites, one mapping to the junction of the 3' rc-mos and the 5' LTR, and the other located 10 nucleotides upstream to this junction, within the 5' LTR. This result indicates that the 3' rc-mos in XRPC-24 was activated by insertion of a promoter provided by the LTR of an IAP genome. Furthermore, the 5' LTR appears to possess promoter activities in two directions. This conclusion was confirmed by the fact that this 5' LTR, in both orientations, was able to activate the bacterial gene coding for chloramphenicol acetyltransferase (CAT) in the modular vector pSVOCAT.
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PMID:Mechanism of activation of the mouse c-mos oncogene by the LTR of an intracisternal A-particle gene. 609 57

Transcobalamin II (TCII) is a plasma protein that binds vitamin B12 (cobalamin; Cbl) and facilitates the cellular uptake of the vitamin by receptor-mediated endocytosis. In genetic disorders that are characterized by congenital deficiency of TCII, intracellular Cbl deficiency occurs, resulting in an early onset of megaloblastic anemia that is sometimes accompanied by a neurologic disorder. To define the genetic basis for TCII deficiency, we have cloned and characterized the human gene that encodes this protein. The gene spans a minimum of 18 kbp and contains nine exons and eight introns, with a polyadenylation signal sequence located 509 bp downstream from the termination codon and a transcription initiation site beginning 158 bp upstream from the ATG translation start site. The 5' flanking DNA does not have a TATA or CCAAT regulatory element, but a 34-nucleotide stretch beginning just upstream of the CAP site contains four tandemly organized 5'-CCCC-3' tetramers. This sequence is a motif for a trans-active transcription factor (ETF) that regulates expression of the epidermal growth factor receptor gene (EGFR), which also lacks TATA and CCAAT regulatory elements. A GC-rich sequence that binds the SP1 protein is located 356 nucleotides upstream from the first of the series of CCCC tetramers. Although this GC sequence is at an unusual location with respect to the CAP site, a 507-bp fragment containing this GC box drives the chloramphenicol acetyltransferase (CAT) reporter gene after transient transfection into NIH 3T3 cells. No CAT activity was observed when a 420-bp fragment lacking this GC box but containing the ETF-binding domains was similarly transfected into this cell line. One consensus and two atypical motifs for the c-myc ligand are located downstream and upstream, respectively, of the GC box, and this could explain the elevated plasma TCII observed in some patients with multiple myeloma, as the c-myc product is overexpressed in some myeloma cells. Restriction endonuclease digestion of genomic DNA from eight normal subjects with Taq I, Hinfl, Msp I, and Bgl I identified three patterns of restriction fragment length polymorphism (RFLP). A number of the exon/intron splice junctions of human TCII, TCI, and IF genes are located in homologous regions of these proteins, providing evidence that these genes have evolved by duplication of an ancestral gene. This characterization of the TCII gene and the RFLP should facilitate the identification of the mutation(s) responsible for the genetic abnormalities of TCII expression.
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PMID:The cloning and characterization of the human transcobalamin II gene. 774 31

We and others have shown that some freshly isolated multiple myeloma (MM) cells and derived cell lines express interleukin 6 (IL-6) receptors and proliferate in vitro in response to IL-6; a subset of MM cells also expresses IL-6 mRNA, is intracytoplasmic IL-6 positive and secretes IL-6. We have shown that MM cells express the cell surface adhesion molecules CD29/CDw49d(VLA-4), CD18/CD11a(LFA-1) and CD44, and may localize to marrow via specific adherence to both extracellular matrix proteins and to bone marrow stromal cells (BMSCs). MM cell adhesion triggers IL-6 secretion by normal and MM BMSCs and related IL-6-mediated tumor cell growth. Our attempts to block MM cell adhesion to BMSC-induced IL-6 secretion by using antibodies to CD29/CDw49d, CD18/11a, and/or CD44 demonstrated minimal effects, suggesting that another ligand-receptor interaction triggers IL-6 secretion when MM cells and BMSCs are juxtaposed. Both MM cells and BMSCs express CD40. Triggering of MM cells and BMSCs via CD40 upregulates IL-6 secretion in both MM cells and MM-derived cell lines, as well as BMSCs and BMSC lines, suggesting the possibility of both autocrine and paracrine MM cell growth triggered via CD40. Finally, experiments using the LP 101 BMSC line transiently transfected with IL-6 promoter fragments linked to chloramphenicol acetyltransferase reporter gene demonstrate that adhesion of MM cells induces IL-6 gene transcription in BMSCs, which is conferred via the NF-kappa B binding motif.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Regulation of interleukin 6 in multiple myeloma and bone marrow stromal cells. 852 May 9

Adhesion of multiple myeloma (MM) cells to bone marrow stromal cells (BMSCs) not only localizes MM cells in the marrow microenvironment, but also triggers interleukin-6 (IL-6) secretion by BMSCs and related MM cell proliferation. In the present study, we characterized the regulation of IL-6 gene expression in BMSCs during MM cell adhesion. Adhesion of ARH-77, HS-Sultan, IM-9, and U266 MM cell lines to BMSCs and BMSC lines (LP 101 and AA 101) triggered 5-through 15-fold and 2-through 4-fold increases in IL-6 secretion, respectively. IL-6 mRNA transcripts were undetectable by Northern blotting in IM-9 MM cells or LP 101 BMSCs cultured alone; however, adherence of IM-9 cells to LP 101 cells induced a transient increase in IL-6 transcripts at 6 hours, followed by peak IL-6 secretion at 24 hours. To confirm increased IL-6 transcription and characterize its regulation, LP101 BMSCs were transiently transfected with full length and deletion fragments of the IL-6 promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene. Transient transfection of LP101 BMSCs with plasmid containing an intact NF-kappa B site showed a 6.8 +/- 0.4-fold increase in CAT activity triggered by IM-9 MM cell adhesion (n = 3, P < .05). Transfection of LP 101 cells with plasmid containing a single base pair deletion from the NF-kapp B binding motif abolished the MM adhesion-induced increase in CAT activity, whereas transfection with plasmid containing three copies of synthetic NF-kappa B sequence resulted in an 8.1 +/- 0.7-fold increase in CAT activity related to MM adhesion (n = 3, P < .05). These data suggest that the NF-kappa B site is one of the essential regulatory elements for MM cell adhesion-induced IL-6 transcription in BMSCs. Electrophoretic mobility shift assays confirmed the involvement of NF-kappa B activation in regulating MM adhesion-induced IL-6 transcription in BMSCs. Further characterization of the upstream events in the signalling cascade regulating IL-6 may not only delineate mechanisms of IL-6 regulation during paracrine MM cell growth, but also provide new therapeutic strategies based on interruption of IL-6 mediated tumor cell growth.
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PMID:Multiple myeloma cell adhesion-induced interleukin-6 expression in bone marrow stromal cells involves activation of NF-kappa B. 856 36


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