Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The response of wild-type and genetically engineered neuroectodermal tumor (NET) cells to exogenous and endogenously synthesized nerve growth factor (NGF) was investigated. Differences in cell proliferation rate, neurite formation, and expression of NGF binding sites were quantitatively determined. Ecotropic retroviral vectors were used to transfer the genes for beta-galactosidase (beta-GAL) and NGF into wild-type C-1300 and Neuro-2A murine neuroblastoma (MNB) and rat pheochromocytoma (PC-12) cells. Conditioned media obtained from NET cells infected with the NGF gene contained biologically active NGF, whereas media from beta-GAL infected cells did not. Infection with the NGF vector induced a short-term decrease in cell proliferation rate and increased neurite formation in wild-type, substrate-adherent PC-12 and Neuro-2A MNB cells (P > 0.05). Incubation of wild-type C-1300, Neuro-2A MNB, and PC-12 cells with NGF (0-200 ng/ml) for 5 days significantly reduced proliferation rates in a concentration-dependent manner and increased neurite extrusion. All NGF-NET cells had a significantly diminished response to the antiproliferative action of exogenous NGF. Ligand binding assays with 125I-NGF demonstrated a marked reduction in the number of NGF binding sites on NGF-NET cells compared to wild type. The attenuated response of NGF-NET cells to exogenous NGF correlated positively with the down-regulation of NGF binding sites. In conclusion, beta-NGF gene transfer into wild-type NET cells induces the synthesis and secretion of NGF, temporarily decreases cell proliferation rate, increases neurite extrusion, down-regulates NGF binding sites, and reduces NET cell responsiveness to NGF. A putative role for NGF may be the modulation of NET cell proliferation and differentiation.
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PMID:Retroviral transfer of the beta-nerve growth factor gene into murine neuroectodermal tumor cells modulates cell proliferation rate, neurite formation, and NGF binding site expression. 1065 Aug 85

Semliki Forest Virus (SFV) is a broad host range RNA virus capable of high-level recombinant protein expression and apoptosis induction in many cell types. We have successfully used a recombinant, replication deficient SFV vector to express the LacZ marker gene product in seven human prostate cell lines, as well as in human prostate tissue explants. Flow cytometry revealed that 40-60% of PPC-1 prostate cancer cells died 24-72 h after infection with SFV-LacZ virus. Most human prostate cancer cell lines expressed high levels of recombinant protein. Infection of human prostate tissue ex vivo led to similarly high expression levels but the recombinant beta-galactosidase was confined to duct epithelial cells. Infection of cell and tissue cultures resulted in detachment of adherent cells from the culture surface and detachment of epithelial cells from the basement membrane of tissue. Our results indicate that SFV may be useful in targeting recombinant protein expression and apoptosis to prostatic duct epithelial cells.
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PMID:Recombinant Semliki forest virus infects and kills human prostate cancer cell lines and prostatic duct epithelial cells ex vivo. 1067 63

Murine gammaherpesvirus 68 (MHV68) is a gammaherpesvirus that was first isolated from murid rodents. MHV68 establishes a latent infection in the spleen and other lymphoid organs. Several gammaherpesviruses, including herpesvirus saimiri, human herpesvirus 8, and MHV68, encode proteins with extensive homology to the D-type cyclins. To study the function of the cyclin homologue, a recombinant MHV68 has been constructed that lacks the cyclin homologue and expresses beta-galactosidase as a marker (MHV68(cy-)). MHV68(cy-) grows in vitro with kinetics and to titers similar to those of the wild type. BALB/c mice infected with mixtures of equivalent amounts of the wild type and MHV68(cy-) show deficient growth of the MHV68(cy-) in an acute infection. Infection of SCID mice with virus mixtures also showed decreased MHV68(cy-) virus growth, indicating that the deficiency is not mediated by T or B cells. Although mice infected with mixtures containing 100 times as much MHV68(cy-) had greater splenic titers of the mutant virus than wild-type virus in acute infection, at 28 days postinfection splenocytes from these mice reactivated primarily wild-type virus. Quantitative PCR data indicate that equivalent genomes were present in the latent state. Reinsertion of the cyclin homologue into the cyclin-deleted virus restored the wild-type phenotype. These results indicate that the MHV68 cyclin D homologue mediates important functions in the acute infection and is required for efficient reactivation from latency.
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PMID:Murine gammaherpesvirus 68 cyclin D homologue is required for efficient reactivation from latency. 1088 40

Our objective was to determine the efficacy of adenoviral-mediated gene therapy with wild-type p53 or p21 in human breast cancer cells and investigate interactions with radiation and chemotherapy. Two human breast cancer cell lines, MDA-MB-231 and MDA-MB-435, both with p53 mutations, were transduced with adenoviral vectors containing wild-type p53 (Ad5CMV-p53) or p21/WAF1/Cip1 (Ad5CMV-p21), and the effects on growth were determined. Infection was combined with low-dose (1.4 - 3.7 Gy) irradiation to see if this would improve transduction efficiency and enhance numbers of cells killed. Transduction with either vector resulted in expression of p21WAF1/cip1 and growth inhibition, although Ad5CMV-p53 transduction produced greater growth inhibition than did Ad5CMV-p21. The cell lines differed in sensitivity to the vectors. The Ad5CMV-p53 vector in a multiplicity of infection (MOI) of 125 resulted in 50% to 80% inhibition of MDA-MB-231, while MOI 250 of the same vector resulted in 27% inhibition of MDA-MB-435. Infection with Ad5CMV-p21 produced modest growth inhibition in both cell lines (< or = 40% at MOI 200), although protein expression was detected at lower viral doses. Low dose gamma-irradiation (1.4 to 3.7 Gy) was used to try and improve the rate of gene transfer. Modest increases in transduction efficiency and duration of expression of a vector containing beta-galactosidase occurred in irradiated breast cancer cells. Radiation 24 hr before transduction with Ad5CMV-p53 increased the proportions of apoptotic MDA-MB-231 cells. The cells transduced with Ad5CMV-p21 were arrested in G1, yet when they were irradiated before adenoviral transduction, the overexpression of p21 protected the cells from the cytotoxic effects of the radiation. Clonogenic assays showed that Ad5CMV-p21 reduced the sensitivity of MDA-MB-231 to VP-16 and paclitaxel. Combining these drugs with Ad5CMV-p53 did not consistently or significantly decrease clonogenic survival.
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PMID:Adenoviral-mediated gene therapy with Ad5CMVp53 and Ad5CMVp21 in combination with standard therapies in human breast cancer cell lines. 1104 64

Expression of the coxsackie-adenovirus receptor (CAR) is a critical determinant in cellular susceptibility to infection with adenovirus-based gene transfer vectors. This study is focused on the hypothesis that manipulation of the cytoplasmic tail and transmembrane regions of CAR can be used to change cell surface levels of CAR and, consequently, to alter the efficiency of Ad-mediated gene transfer. To accomplish this, Flag-tagged ([F]) human CAR ([F]CAR), [F]tailless-CAR (lacking the cytoplasmic tail), and [F]GPI-CAR (containing a GPI lipid anchor instead of the transmembrane and cytoplasmic regions) were exogenously expressed in CHO cells. Analysis of (125)I-labeled anti-Flag antibody binding to transfected cells revealed that [F]tailless-CAR and [F]GPI-CAR were expressed on the cell surface in 1.8- to 2.5-fold higher amounts than [F]CAR, while the total expression levels were similar. Infection with replication-deficient adenovirus encoding beta-galactosidase (Ad-betagal) demonstrated 1.5- to 2-fold higher levels of transgene expression in CHO cells expressing [F]tailless-CAR or [F]GPI-CAR, respectively, compared with cells containing [F]CAR. The form of CAR expressed did not affect the transport of fluorescent Cy3-Ad particles from the cell surface to the nuclear region. These observations indicate that transduction of target cells by Ad vectors can be optimized by increasing cell surface levels of CAR through functional deletion of the tail and membrane protein domains.
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PMID:Manipulation of the cytoplasmic and transmembrane domains alters cell surface levels of the coxsackie-adenovirus receptor and changes the efficiency of adenovirus infection. 1117 39

We have shown that a deletion mutant form of Bcr [Bcr(64-413)] is a strong inhibitor of the tyrosine kinase of Bcr-Abl in vitro and also inhibits its oncogenic growth effects (Liu et al., Cancer Res., 56: 5120-5124, 1996). To determine the effects of this Bcr-Abl kinase inhibitor on chronic myelogenous leukemia (CML) cells, we cloned BCR(64-413) into a recombinant, replication-defective adenovirus to express useful quantities of Bcr(64-413) in a wide variety of cells in culture. Infection of Cos1 cells with plaque-purified virus at a multiplicity of infection of 20-40 induced high expression of Bcr(64-413) as detected by Western blotting. Infection of hematopoietic cells at modest multiplicities of infection (20-40) required special conditions involving shifting cycling cells to a nongrowing condition involving serum starvation and cell crowding. Under these conditions, both Bcr-Abl-positive and -negative hematopoietic cells can be efficiently infected by adenovirus, as demonstrated by 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside staining of cells infected by beta-galactosidase (beta-GAL) adenovirus. We found that expression of Bcr(64-413) in Bcr-Abl-positive K562 and BV-173 cells, but not Bcr-Abl-negative SMS-SB cells, increased cell-cell clumping and inhibited cell growth. In contrast to the effects of the Bcr(64-413) adenovirus, the beta-GAL adenovirus, despite infecting both types of cells, did not block growth or increase cell-cell clumping of Bcr-Abl-positive and -negative hematopoietic cells. Expression of Bcr(64-413) protein in primary cultures of cells from CML patients with active disease interfered with cell growth, induced apoptosis (as measured by annexin staining), and increased cell-cell clumping, whereas the beta-GAL adenovirus and mock-infected cells lacked these effects. In contrast, normal marrow cells did not exhibit these effects on infection with Bcr(64-413) adenovirus. We conclude from these findings that Bcr(64-413) interferes with the oncogenic effects of Bcr-Abl and therefore has the potential for use in therapy of CML.
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PMID:Expression of a truncated first exon BCR sequence in chronic myelogenous leukemia cells blocks cell growth and induces cell death. 1119 51

Pancreatic cancer has a very poor prognosis. Current chemotherapy and radiotherapy regimens are only moderately successful. The tumour suppressor genes p53 and p16(INK4a)encode cell cycle regulatory proteins that are important candidates for gene replacement therapy. Over 80% of pancreatic adenocarcinoma cases lack detectable p16 protein while over 60% contain mutated p53 protein. We used replication-deficient recombinant adenoviruses to reintroduce wild-type p16 and p53 into pancreatic cancer cells in vitro and into subcutaneous pancreatic tumours in an animal model to determine the effect on tumour growth. Significant growth inhibition was observed in all five human pancreatic cell lines with these viruses (P < 0.002) compared with similar control viruses expressing either luciferase or beta-galactosidase. G1 arrest was observed in all cell lines 72 h after infection with Adp16. Infection with Adp53 caused significant levels of apoptosis (P < 0.004). Apoptosis was also observed to a lesser degree (P < 0.03) with the Adp16 vector. Subcutaneous pancreatic tumours, generated in nu-nu mice demonstrated significant growth suppression following injection of Adp53, Adp16 and a combination of both Adp53 and Adp16 (P < 0.0001). These results show that transfer of wild-type p53 and p16 produces significant growth suppression of pancreatic cancer in vitro and in vivo.
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PMID:Adenovirus-mediated transfer of p53 and p16(INK4a) results in pancreatic cancer regression in vitro and in vivo. 1131 91

Infection of Escherichia coli by bacteriophage lambda depends on two membrane protein complexes: (i) maltoporin (LamB) in the outer membrane for adsorption and (ii) the IIC(Man)-IID(Man) complex of the mannose transporter in the inner membrane for DNA penetration. IIC(Man) and IID(Man) are components of the phosphoenolpyruvate: sugar phosphotransferase system (PTS) which together with the IIAB(Man) subunit mediate transport and phosphorylation of sugars. To identify structural determinants important for penetration of lambda DNA, the homologous IIC-IID complexes of E. coli, K. pneumoniae and B. subtilis, and chimeric complexes between the IIC and IID were characterized. All three complexes support sugar transport in E. coli. Only IIC-IID of E. coli and B. subtilis also support bacteriophage lambda infection. The six chimeric complexes had lost transport activity, but three containing IIC of E. coli or B. subtilis continue to support bacteriophage lambda infection. Complexes containing IIC(Man) and fusion proteins between truncated IID(Man) and alkaline phosphatase or beta-galactosidase support penetration of lambda DNA if less than 100 residues are missing from the C-terminus of IID(Man). Truncation of IIC(Man) renders the complex unstable. Taken together, these results suggest, that IIC is the major specificity determinant for lambda infection but that the IIC subunit is stably expressed only in a complex with the IID subunit. Lambda DNA in transit across the periplasmic space, but not transforming plasmid DNA, is inaccessible to the non-specific nuclease NucA of Anabaena sp. targeted to the periplasmic space either in soluble form or as a fusion protein to the C-terminus of IID(Man).
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PMID:Facilitation of bacteriophage lambda DNA injection by inner membrane proteins of the bacterial phosphoenol-pyruvate: carbohydrate phosphotransferase system (PTS). 1136 Oct 66

Purified, high-titer adenovirus encoding murine CD154 (Ad-CD154) or human CD154 (Ad-hCD154) was used to infect lymph node cells isolated from patients with follicle center lymphoma. Infection of lymphoma B cells with Ad-CD154 at a multiplicity of infection (MOI) ratio of 100 or higher resulted in high-level transgene expression. Additionally, upon infection of lymphoma B cells, only Ad-CD154 resulted in surface expression of CD154, despite similar, high-level expression of either human or mouse CD154 by HeLa cells infected with Ad-hCD154 or Ad-CD154, respectively. Moreover, infection of lymphoma B cells with Ad-CD154, but not Ad-hCD154 or adenovirus encoding Eschericheria coli beta-galactosidase (Ad-LacZ), induced the neoplastic B cells to express higher levels of immune co-stimulatory molecules that are required for proficient presentation of antigen to T cells. Consistent with this, we found that Ad-CD154 infected lymphoma B cells could stimulate T cells to proliferate or produce interferon-gamma in allogeneic or autologous mixed lymphocyte interactions. We conclude that lymphoma B cells can be infected with Ad-CD154 and that this significantly enhances their recognition by allogeneic or autologous T cells. As such, Ad-CD154-transduced lymphoma B cells may have potential for the active immune therapy of patients with follicle center lymphoma.
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PMID:T cell activation following infection of primary follicle center lymphoma B cells with adenovirus encoding CD154. 1151 7

Vascular injury stimulates the cytokine-growth factor network in the vascular wall, including transforming growth factor-beta (TGF-beta). Reportedly, the intracellular signaling of TGF-beta is mediated by Smad proteins. We tested the effects of the ectopic expression of inhibitory Smads in cultured rat smooth muscle cells (SMC) to identify the role of TGF-beta/Smad signaling on the phenotypic modulation of SMC. The cells exposed to human recombinant TGF-beta1 (10 ng/ml) were stimulated Smad2 phosphorylation. Infection with the replication-deficient adenovirus vector expressing Smad7, but not bacterial beta-galactosidase or Smad6, was found to inhibit TGF-beta-induced Smad2 phosphorylation in a dose-dependent manner. TGF-beta suppressed the serum-induced proliferation of SMC from 36.3% to 51.0% (p<0.01), as measured by hand-counting, and this inhibition was attenuated by the ectopic expression of Smad7 (from 30.7% to 74.8% of the reduction of TGF-beta-response, p<0.05), but not Smad6. A BrdU incorporation assay also showed that TGF-beta-mediated growth inhibition was attenuated by exogenous Smad7 and that this inhibition can be reversed by an additional expression of exogenous Smad2. TGF-beta increased the expression of alpha-smooth muscle actin and myosin heavy chain by 1.3-fold and 1.6-fold in comparison to the control, respectively, and these increases were attenuated by exogenous Smad7, but not Smad6. Our data indicate that Smads mediate TGF-beta responses on SMC phenotypes. Smad7, but not Smad6, may specifically act as an inhibitor of TGF-beta responses.
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PMID:Ectopic expression of Smad7 inhibits transforming growth factor-beta responses in vascular smooth muscle cells. 1171 67


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