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Quantification
of thrombospondin-1 secretion and expression of αvβ3
and α3β1
integrins and syndecan-1 as cell-surface receptors for
thrombospondin-1 in malignant glioma cell
Hirofumi Naganuma*, Eiji Satoh,
Takayuki Asahara, Kenichi Amagasaki, Arata Watanabe, Hiroki Satoh,
Katsuhiro Kuroda, Lei Zhang, Hideaki Nukui
Department of Neurosurgery,
Faculty of Medicine, University of Yamanashi, 1110 Shimokato,
Tamaho-machi, Nakakoma-gun, Yamanashi, 409-3898, Japan. *Corresponding
Author (nagahiro@yamanashi.ac.jp)
Malignant glioma cells secrete
thrombospondin-1 (TSP-1) which participates in the motility of glioma
cells, and binds to cell surface αvβ3 and α3β1 integrins, and syndecan-1.
This study evaluated the amount of TSP-1 secretion from malignant
glioma cells, and the expression of αvβ3 and α3β1
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 αvβ3 and α3β1
integrins, and syndecan-1 were examined by flow cytometry.
The amounts
of TSP-1 secreted by malignant glioma cells were 43 to 2431 ng/1 × 106 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 μg.
Seven of eight non-glioma cell lines secreted less than 100 0ng of
TSP-1.
All glioma cell lines expressed α3β1 integrin and syndecan-1, and seven of 10 glioma cell
lines expressed αvβ3 integrin.
Treatment of the glioma cell lines with TGF-β2
did not change the expression of αvβ3 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 αvβ3 and α3β1 integrins, and syndecan-1.
Keywords: αvβ3 integrin, α3β1 integrin, invasion, malignant glioma, syndecan-1,
thrombospondin-1
Copyright © 2004 Kluwer Academic Publishers.
All rights reserved
Source: http://ipsapp009.kluweronline.com/IPS/content/ext/x/J/5042/I/126/A/7/abstract.htm
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