Extracellular matrix and the blood-brain barrier in glioblastoma multiforme: spatial segregation of tenascin and agrin.

The quality of the blood-brain barrier (BBB), represented mainly by endothelial tight junctions (TJ), is now believed to be dependent on the brain microenvironment and influenced by the basal lamina of the microvessels. In the highly vascularized glioblastoma multiforme (GBM), a dramatic increase in the permeability of blood vessels is observed but the nature of basal lamina involvement remains to be determined. Agrin, a heparan sulfate proteoglycan, is a component of the basal lamina of BBB microvessels, and growing evidence suggests that it may be important for the maintenance of the BBB.

Chimeric tumor suppressor 1, a p53-derived chimeric tumor suppressor gene, kills p53 mutant and p53 wild-type glioma cells in synergy with irradiation and CD95 ligand.

Adenoviral chimeric tumor suppressor 1 (CTS1) gene transfer was evaluated as a novel approach of somatic gene therapy for malignant glioma. CTS1 is an artificial p53-based gene designed to resist various pathways of p53 inactivation. Here, we report that an adenovirus encoding CTS1 (Ad-CTS1) induces growth arrest and loss of viability in all glioma cell lines examined, in the absence of specific cell cycle changes.

Claudin-1 and claudin-5 expression and tight junction morphology are altered in blood vessels of human glioblastoma multiforme.

The aim of the study was to characterize the interendothelial junctions in tumor microvessels of five cases of human glioblastoma multiforme. In addition to morphological analysis, tumors were screened for the expression of junctional proteins, such as occludin, claudin-1, ZO-1 and catenins. The expression of the tight junction protein claudin-1 was lost in the majority of tumor microvessels, whereas claudin-5 and occludin were significantly down-regulated only in hyperplastic vessels.

R- and B-cadherin expression defines subpopulations of glial cells involved in axonal guidance in the optic nerve head of the chicken.

Glial cells play a crucial role in the organization and function of the nervous system. Cell-cell adhesion receptors of the cadherin family have been shown to participate in distinct morphogenetic processes throughout the development of the CNS, but little is known about glial expression of cadherins. Applying immunofluorescence and confocal laser scanning microscopy, we investigated R- and B-cadherin expression in relation to the glial cell differentiation in the optic nerve head and pecten oculi of developing chicken.

Transepithelial electrical resistance and tight junctions of human gingival keratinocytes.

Human gingival keratinocytes (HGKs) were studied by means of freeze-fracture technique, conventional electron microscopy and the transepithelial electrical resistance for the investigation of intercellular contacts. For the purpose of comparison, MDCK cells and HaCat cells were also included. An unexpected finding was the presence of tight junctions in the HGKs.