Anti-mitotic properties of indirubin-3'-monoxime, a CDK/GSK-3 inhibitor: induction of endoreplication following prophase arrest.
The bis-indole indirubin is the active ingredient of the Traditional Chinese Medicine recipe Danggui Longhui Wan used against chronic myelocytic leukemia. We have previously shown that indirubins are potent inhibitors of cyclin-dependent kinases and glycogen synthase kinase-3. We here investigated the anti-mitotic properties of this class of compounds using the cell permeable indirubin-3'-monoxime and the HBL-100 cell line. Indirubin-3'-monoxime reversibly arrests asynchronous HBL-100 cells in G2. This arrest is not accompanied by any significant change in expression of the major cell cycle regulators. However indirubin-3'-monoxime inhibits the phosphorylation of consensus CDK phosphorylation sites as well as of nucleolin at a specific CDK1/cyclin B phosphorylation site, suggesting a direct action on the mitotic CDK1/cyclin B. When indirubin-3'-monoxime is added to HBL-100 cells synchronized in M phase by nocodazole, cells undergo an endoreplication leading to an 8n DNA content. As soon as indirubin-3'-monoxime is washed away, these polyploid cells become aneuploid and later die from necrosis. This mechanism of endoreplication followed by cell death may contribute to the anti-tumour properties of indirubins.
Damiens
E
E
CNRS, Cell Cycle Group, Station Biologique, B.P. 74, 29682 Roscoff cedex, Bretagne, France.
Baratte
B
B
Marie
D
D
Eisenbrand
G
G
Meijer
L
L
D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors* / Q000235:genetics; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D018797:Cell Cycle Proteins / Q000235:genetics; D016923:Cell Death; D002461:Cell Line, Transformed; D019926:Cyclin B; D016195:G2 Phase; D015870:Gene Expression; D038362:Glycogen Synthase Kinase 3; D038341:Glycogen Synthase Kinases; D006131:Growth Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology*; D008938:Mitosis / Q000502:physiology*; D015394:Molecular Structure; D015739:Nocodazole / Q000494:pharmacology; D011123:Polyploidy; D011418:Prophase
D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D019926:Cyclin B; D006131:Growth Inhibitors; D007211:Indoles; D038341:Glycogen Synthase Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D016203:CDC2 Protein Kinase; D038362:Glycogen Synthase Kinase 3; D015739:Nocodazole; C027185:indirubin