Expression and cellular localization of messenger RNA for plasminogen activator inhibitor type 1 in human astrocytomas in vivo.
We investigated the expression and cellular localization of plasminogen activator inhibitor type 1 (PAI-1) in human astrocytoma in vivo. Northern blot and densitometric quantitation of PAI-1 mRNA indicated that PAI-1 transcripts were significantly higher in human malignant astrocytomas and especially in glioblastomas than in low-grade gliomas and normal brain tissues in vivo. Using in situ hybridization with paraffin-embedded surgical specimens of human gliomas and normal brain tissues, PAI-1 mRNA was abundantly expressed in glioblastomas. PAI-1 mRNA was localized mainly in tumor cells and endothelial cells. The distribution of PAI-1 mRNA expression was particularly abundant around areas of vascular proliferation and in remnant tumor cells surrounding necrotic foci. PAI-1 mRNA was also expressed in both the tumor and endothelial cells of anaplastic astrocytomas, whereas it was not expressed or only weakly expressed in low-grade astrocytomas or normal brain tissues. These results suggest that high expression of PAI-1 is associated with the malignant progression of astrocytic tumors and that excessive PAI-1 expression might be associated with intratumoral necrosis in glioblastomas.
Yamamoto
M
M
Department of Neurosurgery, University of Texas M. D. Anderson Cancer Center, Houston 77030.
Sawaya
R
R
Mohanam
S
S
Loskutoff
D J
DJ
Bruner
J M
JM
Rao
V H
VH
Oka
K
K
Tomonaga
M
M
Nicolson
G L
GL
Rao
J S
JS
D001254:Astrocytoma / Q000737:chemistry*; D001483:Base Sequence; D015152:Blotting, Northern; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000737:chemistry*; D005909:Glioblastoma / Q000737:chemistry*; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis*; D012334:RNA, Neoplasm / Q000032:analysis*
D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D012334:RNA, Neoplasm