Expression of tenascin-C in astrocytic tumors: its relevance to proliferation and angiogenesis.
BACKGROUND
The expression and distribution of the extracellular matrix protein tenascin-C (TN-C) may be enhanced in human astrocytomas. The purpose of this study is to evaluate the expression of TN-C according to histological malignancy of tumor cells and its relevance to neoplastic angiogenesis in human astrocytic tumors.


METHODS
Between 1994 and 1998, 52 astrocytic tumor specimens including 4 pilocytic astrocytomas, 13 astrocytomas, 3 anaplastic astrocytomas, and 32 glioblastomas were used in this study. A retrospective analysis was performed to evaluate a statistical correlation between TN-C expression and proliferative indices. We characterized the expression of TN-C in neoplastic vessels, around individual tumor cells as a tumor network, and in tumor cells by immunohistochemistry using antibodies against human TN-C. The proliferative indices were also investigated by immunostaining with the MIB-1 antibody against the Ki-67 proliferation antigen.


RESULTS
TN-C immunoreactivity was found to be enhanced in tumor vessels and tumor networks of high-grade astrocytic tumors. The vascular TN-C deposition was greater in high-grade than in low-grade astrocytic tumors (p < 0.05). Its expression was the most intense in glioblastomas. Proliferation indices increased with tumor grade and MIB-1 labeling index (LI) was highest in glioblastomas. Moreover, expression of TN-C in tumor vessels was correlated with proliferative indices.


CONCLUSIONS
Our data show that TN-C in human astrocytic tumors may be identified as a factor contributing to malignant progression. And also, enhanced expression of TN-C in tumor vessels having a high proliferative index indicates that TN-C could be involved in neoplastic angiogenesis.
Kim
C H
CH
Department of Neurosurgery, College of Medicine, Hanyang University, Seoul, South Korea.
Bak
K H
KH
Kim
Y S
YS
Kim
J M
JM
Ko
Y
Y
Oh
S J
SJ
Kim
K M
KM
Hong
E K
EK
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D001932:Brain Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D002675:Child, Preschool; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies; D019063:Tenascin / Q000378:metabolism*
D019394:Ki-67 Antigen; D019063:Tenascin