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

Recombinant adenoviruses are highly advantageous as vectors for transferring genes into mammalian cells, but the transfer is not efficient in all types of cells. We investigated the effects of four adenoviral receptors [integrinalphav, integrinbeta3, integrinbeta5, and human coxsackievirus and adenovirus receptor (hCAR)] on adenovirus-mediated transfer of exogenous cDNA into each of 10 glioma cell lines. Transfection efficiency varied widely from one cell line to another (0-100%) when we measured it by infection with AdLacZ, a vector designed to express beta-galactosidase. Levels of integrinalphav and integrinbeta5 expression were similar among the 10 cell lines, but expression of hCAR and integrinbeta3 varied significantly. As these observations indicated a possible correlation between expression of hCAR and the efficiency of gene transfer, we induced the hCAR gene into three glioma cell lines (T98G, U118MG, and U138MG) that expressed hCAR at very low levels and had also revealed low efficiencies of adenoviral gene transfer. In U118MG- and U138MG-derived cells that had regained the ability to express hCAR in stable fashion, adenovirus-mediated gene transfer became highly efficient. Moreover, addition of the peptide corresponding to the extracellular domain of hCAR (ECD-hCAR) by preincubation significantly increased the adenovirus infectivity to these adenovirus-tolerant cells. These results suggest that hCAR could be one of important determinants of the infectivity of adenovirus, and that the ECD-hCAR might be a novel useful tool for improvement of adenovirus-mediated gene therapy against the adenovirus-tolerant cancer cells.
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PMID:Significant increase of adenovirus infectivity in glioma cell lines by extracellular domain of hCAR. 1090 63

Adenovirus vectors are expected to be a powerful tool for gene therapy to treat severe fractures. Adenovirus invades cells through binding to the coxsackievirus and adenovirus receptor (CAR) on the cell membrane. CAR expression is low in normal adult animals, but it is induced on regenerating cells in some experimental models. We made a rib fracture model in mice and evaluated the histological changes and CAR mRNA expression by RT-PCR 1, 5, 10, 14, and 21 days after the fracture. CAR mRNA was expressed exclusively in the fractured ribs at each time point, but not in the normal ribs. We detected the CAR protein immunohistochemically in fibroblast-like cells in the fracture callus on days 10 and 14 after fracture. In situ hybridization showed that these fibroblast-like cells expressed mRNA of type I collagen and osteopontin, but not osteocalcin, defining the cells as immature osteoblasts. We then transferred small doses (10(4)-10(8) PFU) of lacZ-expressing adenovirus vector into immature osteoblasts on day 14. beta-galactosidase was detected only on the immature osteoblasts at every dose. Immature osteoblasts play an important role in the matrix replacement step in fracture healing. CAR-mediated gene transfer into immature osteoblasts can be reasonable for adenovirus-mediated treatment of fracture healing.
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PMID:Coxsackievirus and adenovirus receptor (CAR)-positive immature osteoblasts as targets of adenovirus-mediated gene transfer for fracture healing. 1290 55

We have assessed the ability of bispecific fusion proteins to improve adenovirus-mediated transfer of therapeutic and marker transgenes. We constructed an expression vector that can be easily modified to synthesize a variety of fusion proteins for retargeting adenoviral gene therapy vectors to cell surface markers, which are differentially expressed between normal and cancer cells. Adenoviral transduction can be improved in a number of tumour cell lines which overexpress EGFR (epidermal growth factor receptor) or uPAR (urokinase-type plasminogen activator receptor), but which have only low levels of endogenous hCAR (human coxsackie B and adenovirus receptor) expression. Up to 40-fold improvement in beta-galactosidase transgene expression was seen using an EGFR retargeting protein, and up to 16-fold using a second fusion protein targeting uPAR. In vitro, our uPAR retargeting fusion protein improved the sensitivity to adenoviral herpes simplex virus thymidine kinase/ganciclovir by an order of magnitude, whereas in vivo, our EGFR retargeting protein is able to significantly delay tumour growth in rodent animal models in a dose-dependent manner. The 'cassette' design of our fusion protein constructs offers a flexible method for the straightforward synthesis of multiple adenoviral retargeting proteins, directed against a variety of tumour-associated antigens, for use in clinical trials.
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PMID:Retargeted adenoviral cancer gene therapy for tumour cells overexpressing epidermal growth factor receptor or urokinase-type plasminogen activator receptor. 2041 Sep 26