The α1β1 and α2β1 Integrins Provide Critical Support for Vascular Endothelial Growth Factor Signaling, Endothelial Cell Migration, and Tumor Angiogenesis

Angiogenesis is a complex process, involving functional cooperativity between cytokines and endothelial cell (EC) surface integrins. In this study, we investigated the mechanisms through which the alpha(1)beta(1) and alpha(2)beta(1) integrins support angiogenesis driven by vascular endothelial growth factor (VEGF). Dermal microvascular EC attachment through either alpha(1)beta(1) or alpha(2)beta(1) supported robust VEGF activation of the Erk1/Erk2 (p44/42) mitogen-activated protein kinase signal transduction pathway that drives EC proliferation. Haptotactic EC migration toward collagen I was dependent on alpha(1)beta(1) and alpha(2)beta(1) as was VEGF-stimulated chemotaxis of ECs in a uniform collagen matrix. Consistent with the functions of alpha(1)beta(1) and alpha(2)beta(1) in supporting signal transduction and EC migration, antibody antagonism of either integrin resulted in potent inhibition of VEGF-driven angiogenesis in mouse skin. Moreover, combined antagonism of alpha(1)beta(1) and alpha(2)beta(1) substantially reduced tumor growth and angiogenesis of human squamous cell carcinoma xenografts. Collectively, these studies identify critical collaborative functions for the alpha(1)beta(1) and alpha(2)beta(1) integrins in supporting VEGF signal transduction, EC migration, and tumor angiogenesis.     

The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary

Fluorescencein situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescencein situ hybridization and comparative mapping of the chromosomes of human, great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) and Old World monkeys (Macaca fuscata andCercopithecus aethiops). Inversions were found in the pericentric region of the primate chromosome 2p homologs in great apes, and the hybridization pattern demonstrates the known phylogenetically derived telomere fusion in the line that leads to human chromosome 2. The hybridization of the 2q microlibrary to chromosomes of Old World monkeys gave a different pattern from that in the gorilla and the orang-utan, but a pattern similar to that of chimpanzees. This suggests convergence of chromosomal rearrangements in different phylogenetic lines.     

Self-monitoring in patients with schizophrenia

BACKGROUND: The present study investigated whether a failure of self-monitoring contributes to core syndromes of schizophrenia. METHOD: Three groups of patients with a DSM-IV diagnosis of schizophrenia (n = 27), with either prominent paranoid hallucinatory or disorganization syndrome, or without these symptoms, and a matched healthy control group (n = 23) drew circles on a writing pad connected to a PC monitor. Subjects were instructed to continuously monitor the relationship between their hand movements and their visual consequences. They were asked to detect gain changes in the mapping. Self-monitoring ability and the ability to automatically correct movements were assessed. RESULTS: Patients with either paranoid-hallucinatory syndrome or formal thought disorder were selectively impaired in their ability to detect a mismatch between a self-generated movement and its consequences, but not impaired in their ability to automatically compensate for the gain change. CONCLUSIONS: These results support the claim that a failure of self-monitoring may underlie the core symptoms of schizophrenia.     

Expression of vascular permeability factor/vascular endothelial growth factor by human granulosa and theca lutein cells. Role in corpus luteum development.

Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) is a cytokine that is overexpressed in many tumors, in healing wounds, and in rheumatoid arthritis. VPF/VEGF is thought to induce angiogenesis and accompanying connective tissue stroma in two ways: 1), by increasing microvascular permeability, thereby modifying the extracellular matrix and 2), as an endothelial cell mitogen. VPF/VEGF has been reported in animal corpora lutea and we investigated the possibility that it might be present in human ovaries and have a role in corpus luteum formation. We here report that VPF/VEGF mRNA and protein are expressed by human ovarian granulosa and theca cells late in follicle development and, subsequent to ovulation, by granulosa and theca lutein cells. Therefore, VPF/VEGF is ideally positioned to provoke the increased permeability of thecal blood vessels that occurs shortly before ovulation. VPF/VEGF likely also contributes to the angiogenesis and connective tissue stroma generation that accompany corpus luteum/corpus albicans formation. Finally, VPF/VEGF was overexpressed in the hyperthecotic ovarian stroma of Stein-Leventhal syndrome in which it may also have a pathophysiological role.     

Stimulation of endothelial cell migration by vascular permeability factor/vascular endothelial growth factor through cooperative mechanisms involving the alphavbeta3 integrin, osteopontin, and thrombin.

We have identified several mechanisms by which the angiogenic cytokine vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) likely regulates endothelial cells (EC) migration. VPF/VEGF induced dermal microvascular EC expression of mRNAs encoding the alphav and beta3 integrin subunits resulting in increased levels of the alphavbeta3 heterodimer at the cell surface, and VPF/VEGF also induced mRNA encoding osteopontin (OPN), an alphavbeta3 ligand. OPN promoted EC migration in vitro; and VPF/VEGF induction of alphavbeta3 was accompanied by increased EC migration toward OPN. Because thrombin cleavage of OPN results in substantial enhancement of OPN's adhesive properties, and because VPF/VEGF promotes increased microvascular permeability leading to activation of the extrinsic coagulation pathway, we also investigated whether VPF/VEGF facilitates thrombin cleavage of OPN in vivo. Consistent with this hypothesis, co-injection of VPF/VEGF together with OPN resulted in rapid cleavage of OPN by endogenous thrombin. Furthermore, in comparison with native OPN, thrombin-cleaved OPN stimulated a greater rate of EC migration in vitro, which was additive to the increased migration associated with induction of alpha v beta 3. Thus, these data demonstrate cooperative mechanisms for VPF/VEGF regulation of EC migration involving the alphavbeta3 integrin, the alphavbeta3 ligand OPN, and thrombin cleavage of OPN. These findings also illustrate an operational link between VPF/VEGF induction of EC gene expression and VPF/VEGF enhancement of microvascular permeability, suggesting that these distinct biological activities may act accordingly to stimulate EC migration during angiogenesis.     

The Bioperl toolkit: Perl modules for the life sciences

The Bioperl project is an international open-source collaboration of biologists, bioinformaticians, and computer scientists that has evolved over the past 7 yr into the most comprehensive library of Perl modules available for managing and manipulating life-science information. Bioperl provides an easy-to-use, stable, and consistent programming interface for bioinformatics application programmers. The Bioperl modules have been successfully and repeatedly used to reduce otherwise complex tasks to only a few lines of code. The Bioperl object model has been proven to be flexible enough to support enterprise-level applications such as EnsEMBL, while maintaining an easy learning curve for novice Perl programmers. Bioperl is capable of executing analyses and processing results from programs such as BLAST, ClustalW, or the EMBOSS suite. Interoperation with modules written in Python and Java is supported through the evolving BioCORBA bridge. Bioperl provides access to data stores such as GenBank and SwissProt via a flexible series of sequence input/output modules, and to the emerging common sequence data storage format of the Open Bioinformatics Database Access project. This study describes the overall architecture of the toolkit, the problem domains that it addresses, and gives specific examples of how the toolkit can be used to solve common life-sciences problems. We conclude with a discussion of how the open-source nature of the project has contributed to the development effort.     

Improved detection of chromosome 16 rearrangements in acute myeloid leukemias using 16p and 16q specific microdissection DNA libraries

DNA libraries of the human chromosome arms 16p and 16q have been constructed by means of microdissection for the use of fluorescence in situ hybridization (FISH) analysis of rearranged chromosome 16 in acute myeloid leukemia. FISH with differently labeled chromosome 16p and 16q arm-specific libraries on normal metaphase spreads resulted in bright painting signals on both arms of chromosome 16, each stained in a different color. Hybridization on bone marrow samples of acute leukemia patients having a pericentric inversion of chromosome 16 showed on one chromosome 16 the presence of q-arm specific material on the p-arm adjacent to the centromere and vice versa, resulting in an alternating red-green-red-green colored chromosome pattern in the FISH analysis.     

Efficacy and safety evaluation of human reovirus type 3 in immunocompetent animals: racine and nonhuman primates.

PURPOSE: Human reovirus type 3 has been proposed to kill cancer cells with an activated Ras signaling pathway. The purpose of this study was to investigate the efficacy of reovirus in immunocompetent glioma animal models and safety/toxicity in immunocompetent animals, including nonhuman primates. EXPERIMENTAL DESIGN: Racine glioma cells 9L and RG2 were implanted s.c. or intracranially in Fisher 344 rats with or without reovirus antibodies, followed by treatment of reovirus. To study whether reovirus kills contralateral tumors in the brain and to determine viral distribution, we established an in situ dual tumor model followed by reovirus intratumoral inoculation only into the ipsilateral tumor. To evaluate neurotoxicity/safety of reovirus, Cynomolgus monkeys and immunocompetent rats were given intracranially with reovirus, and pathological examination and/or behavioral studies were done. Viral shedding and clinical biochemistry were systematically studied in monkeys. RESULTS: Intratumorally given reovirus significantly suppressed the growth of both s.c. and intracranially tumors and significantly prolonged survival. The presence of reovirus-neutralizing antibodies did not abort the reovirus' antitumor effect. Reovirus inhibited glioma growth intracranially in the ipsilateral but not the contralateral tumors; viral load in ipsilateral tumors was 15 to 330-fold higher than the contralateral tumors. No encephalitis or behavioral abnormalities were found in monkeys and rats given reovirus intracranially. No treatment-related clinical biochemistry changes or diffuse histopathological abnormality were found in monkeys inoculated intracranially with Good Manufacturing Practice prepared reovirus. Microscopic changes were confined to the region of viral inoculation and were dose related, suggesting reovirus intracranially was well tolerated in nonhuman primates. CONCLUSIONS: These data show the efficacy and safety of reovirus when it is used in the treatment of gliomas in immunocompetent hosts. Inoculation of reovirus into the brain of nonhuman primates did not produce significant toxicities.