Anomalous p27kip1 expression in a subset of malignant gliomas.
p27Kip (p27) expression was immunohistochemically investigated in 28 astrocytic tumors, and compared with the cell proliferation index (MIB-1 staining index). Normal rat brains and surgical specimens from human nonneoplastic brain lesions were used as controls. In the rat brains, the astrocytes were exclusively p27-positive. The reactive astrocytes in various disease processes sometimes lacked p27 expression. The distribution of p27-positive cells was uniform in low-grade astrocytomas and heterogeneous in high-grade tumors. Double staining of p27 and MIB-1 showed a reciprocal pattern in most cases. The frequency of p27 expression was inversely correlated with MIB-1 staining index and tumor grade. However, several malignant gliomas showed high p27 expression in spite of high MIB-1 staining indices. In such cases, MIB-1-positive cells were occasionally p27-positive. In this paper we discuss the etiology of the anomalous p27 expression in a subset of malignant gliomas.
Nakasu
S
S
Department of Neurosurgery, Shiga University of Medical Science, Ohtsu, Japan. snakasu@belle.shiga-med.ac.jp
Nakajima
M
M
Handa
J
J
D000818:Animals; D018797:Cell Cycle Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000378:metabolism*; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis*; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D051381:Rats; D025521:Tumor Suppressor Proteins
C493962:Cdkn1b protein, rat; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases