Immunohistochemical study of tight junction-related protein in neovasculature in astrocytic tumor.
To clarify whether the neovasculature of brain tumors preserves blood-brain barrier (BBB) functions, we studied the expression of a tight junction-related protein, Zo-1, using immunohistochemistry. Twenty-six astrocytic tumors were examined using an anti-Zo-1 Mab, and Zo-1 expression was compared with the expression of vasicular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR) (fit-1), and antiproliferative cell nuclear antigen (PCNA). A positive reaction for Zo-1 was seen in the endothelial cells in micro-blood vessels in all astrocytic tumors. The reactions for Zo-1 in the endothelial cells forming glomeruloid proliferations in newly formed micro-blood vessels in high-grade tumors were weaker than those in the endothelial cells of normal cerebral capillaries. Although there is a negative correlation between positive immunoreactions for BBB-related proteins and the expression of VEGF of the endothelial cells in micro-blood vessels, the proliferative activity of tumor cells, and histological grades, the present findings suggest that the endothelial cells of the neovasculature of high-grade tumors preserve partial BBB function at the cellular level. Because of the ease of immunohistochemical procedures compared with electron microscopic examination, the immunohistochemical detection of Zo-1 should provide a useful marker for tight junctions.
Sawada
T
T
Department of Pathology, Tokyo Women's Medical University, Japan. tapasco@research.twmu.ac.jp
Kato
Y
Y
Kobayashi
M
M
Takekekawa
Y
Y
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000098:blood supply* / Q000503:physiopathology; D001808:Blood Vessels / Q000378:metabolism; D001812:Blood-Brain Barrier; D001932:Brain Neoplasms / Q000098:blood supply* / Q000378:metabolism / Q000503:physiopathology; D002675:Child, Preschool; D004730:Endothelium, Vascular / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D010750:Phosphoproteins / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D013194:Staining and Labeling; D019108:Tight Junctions / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein
D008565:Membrane Proteins; D010750:Phosphoproteins; D018809:Proliferating Cell Nuclear Antigen; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein