Differential expression of tenascin-C and tenascin-X in human astrocytomas.
Tenascins (TNs) are a family of extracellular matrix glycoproteins. The first member of this family to be recognized, tenascin-C (TN-C), is known to be expressed in various tumors including human astrocytomas. Tenascin-X (TN-X) is the latest member of the TN family to be reported, and its expression in tumor tissues has not yet been examined. In this study, we found expression of TN-X in glioma cell lines and human astrocytomas by immunoblot analysis using anti-mouse TN-X antibodies. We also examined the expression of TN-C and TN-X immunohistochemically in a series of 32 human astrocytomas and tissue from 5 normal brains. Expression of TN-X was up-regulated to a higher degree in low-grade astrocytomas than in high-grade astrocytomas. TN-X was mainly localized in the perivascular stroma around tumor vessels, and weakly expressed in the intercellular spaces among tumor cells. In contrast, TN-C was more strongly expressed in the intercellular spaces and in tumor vessels in high-grade astrocytomas (anaplastic astrocytomas and glioblastomas) than in low-grade astrocytomas. In the tissues expressing both TNs, the distribution of TN-X was often reciprocal to that of TN-C. These findings indicate that the expression of TN-C and TN-X in astrocytomas is different, and that these glycoproteins could be involved in neovascularization in different manners.
Hasegawa
K
K
Department of Pathology, Mie University School of Medicine, Japan.
Yoshida
T
T
Matsumoto
K
K
Katsuta
K
K
Waga
S
S
Sakakura
T
T
D000818:Animals; D001254:Astrocytoma / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D019063:Tenascin / Q000096:biosynthesis*; D015854:Up-Regulation / Q000502:physiology
D019063:Tenascin; C081865:tenascin X