The effect of the cyclin-dependent kinase inhibitor olomoucine on cell cycle kinetics.
The effect of the cyclin-dependent (CDK) inhibitors olomoucine and roscovitine on cell kinetics was studied. To this end, nonsmall cell lung cancer (NSCLC) cell line MR65 and neuroblastoma cell line CHP-212 were pulse labeled with bromodeoxyuridine (BrdUrd) and chased in culture medium, to which various concentrations of olomoucine or roscovitine were added. A dose-dependent inhibition of the G1/S-phase and G2/ M-/G1 transitions was observed. Furthermore, S-phase progression was also inhibited in a dose-dependent manner. Similarly, roscovitine, another CDK inhibitor with a 10-fold higher efficiency for both CDK1 and CDK2 as compared to olomoucine, showed the same effects at a 10-fold lower concentration. At the highest tested doses both olomoucine (200 microM) and roscovitine (40 microM) induced a complete cell cycle block in both cell lines, paralleled by the appearance of apoptotic figures. In these cultures a decrease in CDK1 protein level was found as shown by Western blotting. Bivariate CDK1/DNA analysis confirmed these observations and showed that a subpopulation of cells with characteristics of apoptosis became CDK1 negative. The presented data suggest that cyclins and CDKs are involved at an important nodal point shared by pathways regulating cellular proliferation and apoptosis.
Schutte
B
B
Department of Molecular Cell Biology and Genetics, University of Maastricht, The Netherlands. bert.schutte@molcelb.unimaas.nl
Nieland
L
L
van Engeland
M
M
Henfling
M E
ME
Meijer
L
L
Ramaekers
F C
FC
D000963:Antimetabolites / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001973:Bromodeoxyuridine / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology*; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005434:Flow Cytometry; D016195:G2 Phase / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007701:Kinetin; D008175:Lung Neoplasms; D008938:Mitosis / Q000187:drug effects / Q000502:physiology; D009447:Neuroblastoma; D011687:Purines / Q000494:pharmacology*; D000077546:Roscovitine; D016196:S Phase / Q000187:drug effects / Q000502:physiology; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000201:enzymology
D000963:Antimetabolites; D004791:Enzyme Inhibitors; D011687:Purines; D000077546:Roscovitine; C090046:olomoucine; D016203:CDC2 Protein Kinase; D018844:Cyclin-Dependent Kinases; D001973:Bromodeoxyuridine; D007701:Kinetin