An additional copy of the homologous region (hr1) sequence in the Autographa californica multinucleocapsid polyhedrosis virus genome promotes hyperexpression of foreign genes.

The Autographa californica multinucleocapsid nuclear polyhedrosis virus genome contains nine homologous region (hr1, hr1a, hr2, hr2a, hr3, hr4a, hr4b, hr4c, and hr5) sequences that are thought to be involved in viral replication and activation of transcription. Our results show that the 750 bp hr1 sequence is capable of functioning as an enhancer of transcription of foreign genes from the homologous late polyhderin gene promoter and the heterologous Drosophila heat shock protein (hsp70) promoter in insect cells. Introduction of an additional copy of the complete hr1 element downstream to the polyhedrin locus in the viral genome, while not affecting the stability of the recombinant virus for at least 30 serial passages, led to hyperexpression of reporter genes.

The homologous region sequence (hr1) of Autographa californica multinucleocapsid polyhedrosis virus can enhance transcription from non-baculoviral promoters in mammalian cells.

The Autographa californica multinucleocapsid polyhedrosis virus homologous region sequence hr1 enhances transcription from the viral polyhedrin promoter in Spodoptera frugiperda insect cells and independently functions as an origin of replication (ori) sequence. The binding of the host nuclear protein, hr1-binding protein (hr1-BP), is crucial for the enhancer activity (Habib, S., Pandey, S.

Elevated levels of urokinase-type plasminogen activator and its receptor during tumor growth in vivo.

Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) are important in the regulation of tumor tissue progenesis, cell differentiation, tumor cell motility, and tumor cell invasiveness. We have recently reported that the levels of uPA and uPAR were higher in malignant astrocytomas than in low-grade gliomas. In the present study, we measured the levels of uPA and uPAR during the growth of glioblastomas in nude mice.

Elevated levels of Mr 92,000 type IV collagenase during tumor growth in vivo.

Our previous studies demonstrated that matrix metalloproteinase (MMP-9) levels were significantly higher in human glioblastoma tissue samples than in low-grade brain tumors and normal brain tissue (Rao et al., Cancer Res. 53, 2208-2211, 1993).

Site-specific gene delivery in vivo through engineered Sendai viral envelopes.

Inspite of several stimulating developments in gene therapy, the formulation of a targeted gene delivery "vector" is still far from ideal. We have demonstrated the potential of reconstituted Sendai viral envelopes containing only the fusion glycoprotein (F-virosomes) in targeted delivery of reporter genes to liver cells of BALB/c mouse in vivo. The membrane fusion-mediated high efficiency of gene transfer to liver cells was ascertained following a critical evaluation of the level of the DNA, mRNA, and relevant proteins.

Altered in vitro spreading and cytoskeletal organization in human glioma cells by downregulation of urokinase receptor.

The interaction of urokinase-type plasminogen activator (uPA) with its cell-surface receptor (uPAR) is implicated in diverse biological processes such as cell migration, tissue remodeling, and tumor cell invasion. Recent studies indicated that uPAR can act as an extracellular matrix receptor during cell adhesion. Recently, we showed that transfection of the human glioma cell line SNB19 with antisense uPAR resulted in downregulation of uPAR at both the mRNA and protein levels.

Adenovirus-mediated p16/CDKN2 gene transfer suppresses glioma invasion in vitro.

Malignant gliomas extensively infiltrate the surrounding normal brain, and their diffuse invasion is one of the most important barriers to successful therapy. Recent studies indicate that the progression of gliomas from low-grade to high-grade may depend on the acquisition of a new phenotype and the subsequent addition of genetic defects. One of the most frequent abnormalities in the progression of gliomas is the inactivation of tumor-suppressor gene p16, suggesting that loss of p16 is associated with acquisition of malignant characteristics.

Cisplatin but not BCNU inhibits urokinase-type plasminogen activator levels in human glioblastoma cell lines in vitro.

Glioblastomas extensively invade the surrounding normal brain tissue, with a concomitant expression of various proteolytic enzymes, in particular urokinase-type plasminogen activator (uPA). In this study we used cis-diamminedichloroplatinum (cisplatin) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), commonly used anti-cancer drugs for the treatment of glioblastomas, to study the expression of uPA in three human glioblastoma cell lines in vitro. Cells were treated with 25 microM cisplatin and 50 microM BCNU, and uPA levels were estimated by fibrin zymography during a 72-h time course.

Inhibition of in vivo tumorigenicity and invasiveness of a human glioblastoma cell line transfected with antisense uPAR vectors.

Our previous studies showed that glioblastomas express increased urokinase-type plasminogen activator receptors (uPARs) in comparison to low-grade gliomas (Yamamoto et al., Cancer Res., 54, 5016-5020, 1994).

Effect of cisplatin and BCNU on MMP-2 levels in human glioblastoma cell lines in vitro.

Matrix metalloproteinases (MMPs) play an important role in various physiological and pathological conditions such as tissue remodeling, and cancer cell invasion and metastasis. The aim of this study was to determine the effect of the antitumor compounds cis-dichlorodiammine platinum (ii) (cisplatin) and 1, 3 bis (2-chloroethyl)-1-nitrosourea (BCNU) on 72-kDa type IV collagenase activity (MMP-2) in human gliomas. Human glioblastoma cell lines were treated with cisplatin (25 microM), and BCNU (50 microM), and the levels of MMP-2 were estimated in serum-free conditioned medium and in cell extracts at different time intervals.

Involvement of host factors in transcription from baculovirus very late promoters -- a review.

The baculovirus expression vector system has emerged as the system of choice for the expression of a number of heterologous genes of both prokaryotic and eukaryotic origin. This system utilizes the baculovirus very late, hyperactive polyhedrin and p10 promoters to drive the transcription of foreign genes. Regulation of transcription from these promoters is presently not well understood even though a number of viral gene products that may be important for transcription have been identified.

In vitro inhibition of human glioblastoma cell line invasiveness by antisense uPA receptor.

The cell surface urokinase-type plasminogen activator receptor (uPAR) has been shown to be a key molecule in regulating plasminogen-mediated extracellular proteolysis. To investigate the role of uPAR in invasion of brain tumors, human glioblastoma cell line SNB19 was stably transfected with a vector capable of expressing an antisense transcript complementary to the 300 base pair of the 5' end of the uPAR mRNA. Parental and stably transfected (vector, sense, and antisense) cell lines were analysed for uPAR mRNA transcript by Northern blot analysis, and receptor protein levels were measured by radioreceptor assays and Western blotting.

A recombination-efficient baculovirus vector for simultaneous expression of multiple genes.

The baculovirus system is an extremely powerful tool for expression of heterologous genes in eukaryotic environment. A multiple expression vector, pBacUCmP3, was constructed which harbored two copies of the Autographa californica nuclear polyhedrosis virus very late gene promoter and the Drosophila melanogaster 70-kDa heat-shock protein (hsp70) promoter with downstream unique restriction sites for cloning of three independent foreign genes. Co-transfection of pBacUCmP3 with Bsu36I-linearized viral DNA yields recombinant progeny viruses at very high frequencies.

Characterization of superoxide dismutase from south Indian scorpion venom.

A manganese containing superoxide dismutase was purified to homogeneity from the venom of scorpion Heterometrus fulvipes by ammonium sulfate fractionation followed by gel filtration on Sephadex G-100 and ion exchange chromatography on DEAE-cellulose. The enzyme has a molecular weight of 100,000. Optimum pH for enzyme activity was 8.

Predicted secondary structure of glycogen phosphorylase from Escherichia coli as deduced using Chou-Fasman analysis.

Secondary structure of glycogen phosphorylase from Escherichia coli has been deduced using Chou-Fasman analysis. Out of 809 amino acid residues, 244 residues showed formation of alpha-helix (30%), 218 residues beta-pleated sheet (27%) and 192 residues (24%) showed formation of reverse beta turn, distributed all over the sequence. There are total 27 alpha-helix and 31 beta-pleated sheets distributed all over the molecule.

Purification of isozymes of superoxide dismutase from groundnut (Arachis hypogea) seedlings.

Groundnut seedlings contain five isozymes of superoxide dismutase. These isozymes were purified to homogeneity by ammonium sulfate precipitation, ionexchange chromatography on diethyl amino ethyl cellulose, gel filtration using Sephadex G100 and preparative gel electrophoresis. Manganese containing superoxide dismutase showed optimal activity at pH 7.

Isolation and characterization of hyaluronidase from scorpion (Heterometrus fulvipes) venom.

Hyaluronidase (Hyaluronate lyase, E.C. 3.

Purification and properties of phospholipase A2 from the venom of scorpion, (Heterometrus fulvipes).

Phospholipase A2 was purified about 78 fold from the venom of scorpion Heterometrus fulvipes. The molecular weight of the enzyme was found to be 16,000 and it was optimally active at pH 7.4 and at 50 degrees C.

Subcellular Localization and Identification of Superoxide Dismutase Isoenzymes from Pennisetum typhoideum Seedlings.

Three isoenzymes of superoxide dismutase were identified in germinating seeds of Pennisetum typhoideum. Isoenzyme-I was localized in chloroplasts and isoenzyme-II was found to be associated with mitochondria. By using inhibitors isoenzyme-I and III were tentatively identified as Cu-Zn superoxide dismutases and isoenzyme-II as a Mn-containing enzyme.

Studies on Isoenzymes of Superoxide Dismutase from Mung Bean (Vigna radiata) Seedlings.

Mung bean seedlings contain three isoenzymes of superoxide dismutase. The variations in superoxide dismutase activity and isoenzyme pattern in the whole seedling and in different parts of the seedling such as embryonic axis, cotyledons, roots, and leaves is reported. Superoxide dismutase-I and II are localized in the chloroplasts.

Haemolytic effect of the scorpion Heterometrus fulvipes venom.

The haemolytic effect of the venom from scorpion Heterometrus fulvipes was studied using sheep erythrocytes. While there was no haemolytic effect seen directly by the erythrocytes, erythrocytes sensitized with homologous haemolysin were lysed by the venom. This factor in Heterometrus fulvipes venom having a 'complement like' haemolytic effect was found to be thermolabile and dialysable and sensitive to the action of 2-mercaptoethanol.

Effect of scorpion Heterometrus fulvipes venom on metabolism of rat liver mitochondria.

The scorpion venom Heterometrus fulvipes was able to uncouple the state-4 respiration of rat liver mitochondria. The venom caused mitochondrial swelling and was found to be inhibitory to mitochondrial succinate and glutamate dehydrogenases. Bovine serum albumin was able to protect against mitochondrial swelling.

Influence of bleomycin on the metabolism of dermal collagen in albino rats.

The metabolism of collagen in male rats by treatment with bleomycin was studied following the injection of [3H]proline and the determination of specific and total activity of [3H]hydroxyproline in skin collagen fractions and urine. In the case of the bleomycin-treated animals, there was found to be an increase in the neutral salt soluble collagen content with no change in insoluble collagen content as compared to the control group. The specific and total radioactivity of [3H]hydroxyproline in soluble and insoluble collagen fractions was also increased.