Cell cycle control with minimal participation of Cdk2 in a murine fibrosarcoma clone cultured in protein-free medium.
The differences in the protein expression of cyclins, cyclin-dependent kinases (cdks), and their inhibitors and cdk kinase activities were examined in serum dependent (SD) and independent (PF) clones of the murine fibrosarcoma cell line, Gc-4. The expression of cyclin A in SD was minimal in contrast to PF. Furthermore, cdk2 kinase activity in PF was remarkably lower than that in SD, yet the G1/S transition in PF appeared normal. PF was also resistant against the selective inhibitor of cdk2, butyrolactone I. These findings suggest that tumor cell proliferation and tumor progression can be promoted by the activation of a molecule(s) downstream of cdk2.
Dobashi
Y
Y
Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.
Chigira
M
M
Shoji
M
M
Wakata
Y
Y
Kitagawa
M
M
Tamauchi
H
H
Akiyama
T
T
Kameya
T
T
D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D042846:CDC2-CDC28 Kinases; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division / Q000187:drug effects; D002469:Cell Separation; D016895:Culture Media, Serum-Free; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D005354:Fibrosarcoma / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D014407:Tumor Cells, Cultured
D016895:Culture Media, Serum-Free; D016213:Cyclins; D004791:Enzyme Inhibitors; D011518:Proto-Oncogene Proteins; C082868:butyrolactone I; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495893:Cdk2 protein, mouse; C495902:Cdk4 protein, mouse; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases; D015107:4-Butyrolactone