Quantification of thrombospondin-1 secretion and expression of alphavbeta3 and alpha3beta1 integrins and syndecan-1 as cell-surface receptors for thrombospondin-1 in malignant glioma cells.
Malignant glioma cells secrete thrombospondin-1 (TSP-1) which participates in the motility of glioma cells, and binds to cell surface alphavbeta3 and alpha3beta1 integrins, and syndecan-1. This study evaluated the amount of TSP-1 secretion from malignant glioma cells, and the expression of alphavbeta3 and alpha3beta1 integrins, and syndecan-1. The amounts of TSP-1 in the supernatants from 10 malignant glioma cell lines and eight non-glioma malignant tumor cell lines were measured by enzyme-linked immunosorbent assay. Expression of alphavbeta3 and alpha3beta1 integrins, and syndecan-1 were examined by flow cytometry. The amounts of TSP-1 secreted by malignant glioma cells were 43 to 2431 ng/l x 10(6) cells/24 h (mean +/- SD = 626 +/- 792). Seven of 10 glioma cell lines secreted more than 100 ng of TSP-1 and three of these cell lines secreted more than 1 microg. Seven of eight non-glioma cell lines secreted less than 100 ng of TSP-1. All glioma cell lines expressed alpha3beta1 integrin and syndecan-1, and seven of 10 glioma cell lines expressed alphavbeta3 integrin. Treatment of the glioma cell lines with TGF-beta2 did not change the expression of alphavbeta3 integrin. These results suggest that malignant glioma cells secrete high levels of TSP-1, which may be important in the migration of glioma cells via interactions with alphavbeta3 and alpha3beta1 integrins, and syndecan-1.
Naganuma
Hirofumi
H
Department of Neurosurgery, University of Yamanashi Faculty of Medicine, Nakakoma-gun, Yamanashi, Japan. nagahiro@yamanashi.ac.jp
Satoh
Eiji
E
Asahara
Takayuki
T
Amagasaki
Kenichi
K
Watanabe
Arata
A
Satoh
Hiroki
H
Kuroda
Katsuhiro
K
Zhang
Lei
L
Nukui
Hideaki
H
D001932:Brain Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D039201:Integrin alpha3beta1 / Q000096:biosynthesis*; D039302:Integrin alphaVbeta3 / Q000096:biosynthesis*; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D011509:Proteoglycans / Q000096:biosynthesis*; D053668:Syndecan-1; D053667:Syndecans; D019700:Thrombospondin 1 / Q000378:metabolism*
D039201:Integrin alpha3beta1; D039302:Integrin alphaVbeta3; D008562:Membrane Glycoproteins; D011509:Proteoglycans; C508241:SDC1 protein, human; D053668:Syndecan-1; D053667:Syndecans; D019700:Thrombospondin 1