Effect of hyperthermia on cyclin B expression in a human glioblastoma cell line.
Effects of hyperthermia on the cell kinetics of glioblastoma cells were investigated using flow cytometry. Pulse-labeling with 5-bromodeoxyuridine (BUdR) and chasing of the labeled cells revealed temporary accumulation of the labeled cells in G2M phase and a reduction of DNA synthesis. The level of cyclin B rises rapidly in G2 phase and falls at the end of mitosis in normal cycling cells. Cyclin B binds to p34cdc2, resulting in histone kinase activity which is necessary for the initiation of mitosis. The amount of p34cdc2 remains constant throughout the cell cycle. The level of cyclin B was measured using an anti-cyclin B antibody and flow cytometry in order to investigate the cause of the G2 accumulation induced by hyperthermia. A low level of cyclin B, in comparison with that of normal cycling cells, persisted for more than 3 h after hyperthermia. These results indicate that the temporary accumulation of cells in G2M phase after hyperthermia may be caused, at least in part, by an insufficient level of cyclin B.
Department of Neurosurgery, Yamaguchi University School of Medicine, Japan.
N
N
Ohshita
T
T
Nishizaki
H
H
Ishihara
H
H
Ito
T
T
Murakami
Y
Y
Mimura
D000911:Antibodies, Monoclonal; D001932:Brain Neoplasms / Q000378:metabolism*; D001973:Bromodeoxyuridine; D016203:CDC2 Protein Kinase / Q000096:biosynthesis; D002453:Cell Cycle; D016213:Cyclins / Q000096:biosynthesis*; D004273:DNA, Neoplasm / Q000378:metabolism; D005434:Flow Cytometry; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D006979:Hyperthermia, Induced; D007150:Immunohistochemistry; D011485:Protein Binding; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D016213:Cyclins; D004273:DNA, Neoplasm; D016203:CDC2 Protein Kinase; D001973:Bromodeoxyuridine