Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuregulin, the putative ligand of the c-neu receptor tyrosine kinase, can induce differentiation or growth of epithelia and other cells. To gain insight into the biological role of this factor, we have analyzed the expression of neuregulin during mouse embryogenesis and in the perinatal animal by a combination of in situ hybridization and RNase protection experiments. We identify sites of expression that correspond to mesenchymal cells of various parenchymal organs. Our finding implies a function of neuregulin as a mesenchymal factor that acts on epithelia. The mesenchymal expression of neuregulin could thus provide a molecular basis for the biological phenomenon of mesenchymal-epithelial interactions. It also has implications on the molecular mechanism by which amplification of c-neu can affect tumor progression of carcinomas. In addition, neuregulin expression is found in neuronal cells during development. We show by RNase protection experiments that distinct isoforms of neuregulin are expressed in the brain. Therefore, our data indicate in vivo a dual role for neuregulin as mesenchymal and neuronal factor.
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PMID:Distinct isoforms of neuregulin are expressed in mesenchymal and neuronal cells during mouse development. 830 32

Expression of the activated neu oncogene in transgenic mice has been associated with both the synchronous (single-step) and the stochastic (multistep) transformation of the mammary epithelium. To determine the basis for these conflicting observations, additional strains of transgenic mice carrying the activated neu oncogene under the transcriptional control of the mouse mammary tumor virus promoter/enhancer were produced. Activated neu transgene expression, as measured by in situ hybridization and ribonuclease protection assays, resulted in rapid conversion of the normal mammary epithelium to malignant phenotype in three independent strains of mice. Expression of the transgene in male mice led to epithelial hyperplasia of the epididymis and male infertility but not malignancy. These results indicate that tissue context is an important parameter in malignant progression and that expression of appropriate levels of activated neu is sufficient for rapid production of mammary tumors in transgenic mice.
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PMID:Activated neu induces rapid tumor progression. 863 5

The retinoblastoma tumor suppressor gene product (pRb) is involved in controlling cell cycle progression from G1 into S. pRb functions, in part, by regulating the activities of several transcription factors, making pRb involved in the transcriptional control of cellular genes. Transient-transfection assays have implicated pRb in the transcription of several genes, including c-fos, the interleukin-6 gene, c-myc, cdc-2, c-neu, and the transforming growth factor beta2 gene. However, these assays place the promoter in an artificial context and exclude the effects of far 5' upstream regions and chromosomal architecture on gene transcription. In these experiments, we have studied the role of pRb in the control of cell cycle-related genes within a chromosomal context and within the context of the G1 phase of the cell cycle. We have used adenovirus vectors to overexpress pRb in human osteosarcoma cells and breast cells synchronized in early G1. By RNase protection assays, we have assayed the effects of this virus-produced pRb on gene expression in these cells. These results indicate that pRb is involved in the transcriptional downregulation of the E2F-1, E2F-2, dihydrofolate reductase, thymidine kinase, c-myc, proliferating-cell nuclear antigen, p107, and p21/Cip1 genes. However, it has no effect on the transcription of the E2F-3, E2F-4, E2F-5, DP-1, DP-2, or p16/Ink4 genes. The results are consistent with the notion that pRb controls the transcription of genes involved in S-phase promotion. They also suggest that pRb negatively regulates the transcription of two of the transcription factors whose activity it also represses, E2F-1 and E2F-2, and that it plays a role in downregulating the immediate-early gene response to serum stimulation.
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PMID:Regulation of cellular genes in a chromosomal context by the retinoblastoma tumor suppressor protein. 967 66

Tumor-targeted vectors with controllable expression of therapeutic genes and specific antitumor antibodies are promising tools for the reduction of malignant tumors. Here we describe a new plasmid for the eukaryotic expression of an anti-HER2/neu mini-antibody-barnase fusion protein (4D5 scFv-barnase-His(5)) with an NH(2)-terminal leader peptide. The 4D5 scFv-barnase-His(5) gene was placed downstream of the tetracycline responsive-element minimal promoter in the vector using the Tet-Off gene-expression system. The Bacillus amyloliquefaciens ribonuclease barnase is toxic for the host cells. To overcome this problem, barstar gene under its own minimal cytomegalovirus promoter was used in designed vector. Barstar inhibits the background level of barnase in the cells in the presence of tetracycline in culture medium. The HEK 293T cells were transfected with the designed vector, and the 4D5 scFv-barnase-His(5) fusion protein was identified by anti-barnase antibodies in cell culture medium and after purification from cell lysates using metal-affinity chromatography. The overexpression of the anti-HER2/neu mini-antibody-barnase fusion protein decreased the intensity of fluorescence of HEK 293T cells co-transfected with the generated plasmid and a plasmid containing the gene of enhanced green fluorescent protein (pEGFP-N1), in comparison with the intensity of fluorescence of HEK 293T cells transfected with pEGFP-N1, in the absence of tetracycline in the medium. The effect of the 4D5 scFv-barnase-His(5) on EGFP fluorescence indicates that the introduced barnase functions as a ribonuclease inside the cells. The anti-HER2/neu mini-antibody could be used to deliver barnase to HER2/neu-positive cells and provide its penetration into the target cells, as HER2/neu is a ligand-internalizing receptor. This expression vector has potential applications to both gene and antibody therapies of cancer.
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PMID:A new vector for controllable expression of an anti-HER2/neu mini-antibody-barnase fusion protein in HEK 293T cells. 1630 Sep 8

A three-component nanoparticle consisting of biotinylated Trastuzumab antiHer2 antibody, tat transferring peptide and radiolabeled antisense oligomer, linked together through streptavidin, have shown promise in the delivery to Her2+ tumor in mice following intravenous administration and with evidence of radiotherapeutic efficacy. These results have encouraged us to consider the nanoparticle as a delivery vehicle for RNA interference therapy in which the radiolabeled antisense oligomer is replaced with an unlabeled siRNA duplex. The siRNA stability within the nanoparticle was first confirmed by incubation with RNase A. The interferon responses, that indicate off-target cytotoxicity, were evaluated by quantitative real-time RT-PCR in BT-474 (Her2+) human breast cancer cells by measuring the mRNA expression of 2', 5'-oligoadenylate synthetase (OAS1) and Stat-1, two key interferon-responsive genes. Thereafter the cytotoxicity induced by the siRNA nanoparticle was evaluated by a clonogenic survival assay in BT-474 cells while the Her2 expression of these target cells was evaluated for evidence of specific gene silencing. The siRNA within the three-component anti- Her2/neu siRNA nanoparticle was largely protected from RNase-dependent degradation and did not activate an interferon response. The nanoparticle effectively and significantly inhibited colony formation of the target cells and silenced the Her2 gene expression at 5 nM compared with the identical nanoparticle with a scrambled siRNA. Our delivery nanoparticle, with tumor targeting provided by the antibody and its accumulation without entrapment, possibly due to the transfecting peptide, delivered an siRNA duplex to the proper subcellular localization for specific and effective gene silencing in culture by what appears to be an siRNA mechanism.
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PMID:Her2/neu small interfering RNA delivered in culture by a streptavidin nanoparticle. 2252 71

Mms6 is a protein that plays crucial role in the biomineralization and formation of magnetosomes in magnetotactic bacteria Magnetospirillum magneticum (strain AMB-1). We developed a fusion protein of C-term part of Mms6 and Barstar (natural inhibitor of ribonuclease Barnase), namely, Bs-C-Mms6. This protein successfully stabilized uncoated monocrystalline Fe3O4 magnetite nanoparticles in buffered solutions. Here, we present data regarding the synthesis and characterization of magnetite nanoparticles stabilized with Bs-C-Mms6. For further interpretation of the data presented in this article, please see the research article 'Self-assembling nanoparticles biofunctionalized with magnetite-binding protein for the targeted delivery to HER2/neu overexpressing cancer cells' (Shipunova et al., 2018) [1].
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PMID:Data on characterization of magnetic nanoparticles stabilized with fusion protein of Barstar and C-term part of Mms6. 3050 96