Correlation between bradykinin-induced blood-tumor barrier permeability and B2 receptor expression in experimental brain tumors

Citation
Yh. Liu et al., Correlation between bradykinin-induced blood-tumor barrier permeability and B2 receptor expression in experimental brain tumors, NEUROL RES, 23(4), 2001, pp. 379-387
Citations number
46
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
NEUROLOGICAL RESEARCH
ISSN journal
0161-6412 → ACNP
Volume
23
Issue
4
Year of publication
2001
Pages
379 - 387
Database
ISI
SICI code
0161-6412(200106)23:4<379:CBBBBP>2.0.ZU;2-4
Abstract
Localization of B2 receptors in brain tumor cells and microvessel endotheli al cells of the brain tumors was investigated to study the differential sen sitivity of brain tumors to bradykinin. The present study shows that B2 rec eptor expression levels vary in cultured RG2, C6 and 9L glioma cells as wel l as in the intracerebral tumors established with these cell lines in rats. The double immunohistochemical data indicate that B2 receptors are localiz ed to tumor cells and not to the tumor capillaries. Immunostaining and West ern blot analysis for B2 receptor showed that the B2 receptor expression wa s in the order C6 > RG2 > 9L. The permeability studies on RG2, C6 and 9L tu mors in rats showed that C6 tumor had the highest increase (178%) in K-i (u nidirectional transport across blood-brain barrier (BBB)/blood-tumor barrie r (BTB)), while 9L tumor had the least increase of K-i (35%) over the contr ol group, following intracarotid infusion of bradykinin. We found a positiv e correlation (r=0.965, p < 0.001) between B2 receptor levels and bradykini n-induced increase in BTB permeability. We conclude that B2 receptors are l ocalized to tumor cells and not to normal or tumor capillary endothelial ce lls. C6 tumor with highest B2 receptor expression was most responsive to br adykinin, while RG2 and 9L tumors with lower B2 receptor expression level w ere less sensitive to bradykinin with regard to BTB permeability.