Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Combination therapy can help overcome limitations in the treatment of heterogeneous tumors. In the current study, we examined whether multiple therapeutic agents could be targeted to anti-dansyl single-chain antibodies (DNS scFv) that were anchored on the plasma membrane of cancer cells. Functional DNS scFv could be stably expressed on CT-26 colon cancer cells both in vitro and in vivo. Dansyl moieties were covalently attached to recombinant beta-glucuronidase (betaG) and interleukin 2 (IL-2) via a flexible poly(ethylene glycol) linker to form DNS-PEG-betaG and DNS-PEG-IL-2 conjugates. The conjugates displayed enzymatic and splenocyte-stimulatory activities, respectively, that were similar to those of the unmodified proteins. The conjugates selectively bound CT-26 cells that expressed anti-DNS scFv (CT-26/DNS cells) but not CT-26 cells that expressed control scFv (CT-26/phOx cells). DNS-PEG-betaG preferentially activated a glucuronide prodrug (BHAMG) of p-hydroxy aniline mustard at CT-26/DNS cells in culture and accumulated in subcutaneous CT-26/DNS tumors after intravenous administration. Systemic administration of DNS-PEG-IL-2 or DNS-PEG-betaG and BHAMG significantly delayed the growth of CT-26/DNS but not control CT-26/phOx tumors. Combination treatment with DNS-PEG-betaG and BHAMG followed by DNS-PEG-IL-2 therapy significantly suppressed the growth of CT-26/DNS tumors as compared to either single-agent regimen. These results show that at least two DNS-modified therapeutic agents can be selectively delivered to DNS scFv receptors in vitro and in vivo, allowing combination therapy of DNS scFv-modified tumors.
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PMID:Combination cancer therapy by hapten-targeted prodrug-activating enzymes and cytokines. 1670 8

Transient assay systems using protoplasts have been utilized in several plant species and are a powerful tool for rapid functional gene analysis and biochemical manipulations. A protoplast system has not been used in switchgrass (Panicum virgatum L.), even though it is a bioenergy crop that has received considerable attention. Here we report the first protocol to isolate large numbers of viable protoplasts from both leaves and roots of two switchgrass genotypes. Furthermore, we demonstrate transient expression of PEG-mediated DNA uptake in the isolated protoplasts by measuring the activity of beta-glucuronidase (GUS) reporter gene driven by either the Cauliflower mosaic virus (CaMV) 35S promoter or the maize ubiquitin 1 promoter. Protoplast transformation with either the 35S or the ubiquitin promoter resulted in an increase in GUS activity compared to the untransformed controls; however, the extent of GUS activity was considerably higher for the ubiquitin promoter than for the 35S promoter. Collectively, our results indicate an efficient protoplast isolation and transient assay system that can be used to facilitate gene expression studies in switchgrass.
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PMID:Protoplast isolation and transient gene expression in switchgrass, Panicum virgatum L. 1806 11

CBF/DREB (C-repeat binding factor/dehydration responsive element binding factor) family of transcription factors in plants is reported to be associated with regulation of gene expression under stress conditions. Here, we report the functional characterization of a DREB transcription factor, DREB1B gene from rice (Oryza sativa ssp. indica). The OsDREB1B gene was differentially regulated at the transcriptional level by osmotic stress, oxidative stress, salicylic acid, ABA, and cold. A 745 bp promoter region of OsDREB1B cDNA was fused to the beta-glucuronidase (GUS) gene and introduced via Agrobacterium tumifaciens into the genome of Arabidopsis. Histochemical analysis of GUS expression in T(2) transgenic Arabidopsis plants indicated that OsDREB1B shows stress-specific induction pattern in response to a variety of stresses like mannitol, NaCl, PEG, methyl viologen, cold, ABA, and salicylic acid. Leaf-order-dependent induction pattern of the promoter was observed in response to both cold and ABA stresses. Further, OsDREB1B cDNA was introduced into tobacco plants under the control of CaMV35S promoter to investigate the role of DREB1B product in plant stress response. Transgenic tobacco plants have shown improved seed germination, root growth, membrane stability, and 2, 2-diphenyl-1-pycrilhydrazil hydrate (DPPH) free radical scavenging activity under inhibitory concentrations of mannitol. Importantly, transgenic plants accumulated higher fresh weight under long-term osmotic stress, and also have shown retention of more water than the wild type during drought stress. Overexpression of OsDREB1B in tobacco also improved the oxidative and freezing stress tolerance of transgenic plants. In addition, tobacco plants constitutively expressing OsDREB1B have shown decreased sensitivity to tobacco streak virus infection. Constitutive expression of OsDREB1B in tobacco also induced the expression of PR genes in transgenic plants. The data obtained provide strong in vivo evidence that OsDREB1B is involved in both abiotic and biotic stress responses, and confers broad-spectrum stress tolerance to transgenic plants.
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PMID:Rice DREB1B promoter shows distinct stress-specific responses, and the overexpression of cDNA in tobacco confers improved abiotic and biotic stress tolerance. 1875 79

We have previously isolated a Brassica juncea cDNA encoding a novel chitinase BjCHI1 with two chitin-binding domains (Zhao and Chye in Plant Mol Biol 40:1009-1018, 1999). The expression of BjCHI1 was highly inducible by methyl jasmonate (MeJA) treatment, wounding, caterpillar feeding, and pathogenic fungal infection. These observations suggest that the promoter of BjCHI1 gene might contain specific cis-acting elements for stress responses. Here, we report the cloning and characterization of the BjCHI1 promoter. A 1,098 bp BjCHI1 genomic DNA fragment upstream of the ATG start codon was isolated by PCR walking and various constructs were made by fusing the BjCHI1 promoter or its derivatives to beta-glucuronidase reporter gene. The transgenic Arabidopsis plants showed that the BjCHI1 promoter responded to wounding and MeJA treatment, and to treatments with either NaCl or polyethyleneglycol (PEG 6000), indicating that the BjCHI1 promoter responses to both biotic and abiotic stresses. A transient gene expression system of Nicotiana benthamiana leaves was adopted for promoter deletion analysis, and the results showed that a 76 bp region from -695 to -620 in the BjCHI1 promoter was necessary for MeJA-responsive expression. Furthermore, removal of a conserved T/G-box (AACGTG) at -353 to -348 of the promoter greatly reduced the induction by MeJA. This is the first T/G-box element identified in a chitinase gene promoter. Gain-of-function analysis demonstrated that the cis-acting element present in the 76 bp region requires coupling with the T/G-box to confer full magnitude of BjCHI1 induction by MeJA.
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PMID:Molecular cloning and characterization of the promoter for the multiple stress-inducible gene BjCHI1 from Brassica juncea. 1927 2


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