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Inhibition of glycogen synthase kinase-3 beta induces apoptosis and mitotic catastrophe by disrupting centrosome regulation in cancer cells.

Yoshino Y, Ishioka C - Sci Rep (2015)

Bottom Line: After GSK-3β inhibitor treatment, these cells exhibited characteristic features of mitotic catastrophe, including distended and multivesiculated nuclei and inappropriate reductions in cyclin B1 expression.From these data, GSK-3β seems to regulate centrosome function.Thus, we propose that centrosome dysregulation is an important mechanism for the anticancer effects of GSK-3β inhibitors and that mitotic catastrophe serves as a safe-guard system to remove cells with any mitotic abnormalities induced by GSK-3β inhibition.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Oncology, Institute of Development, Aging and Cancer, Tohoku University, Seiryo-machi 4-1, Aoba-ku, Sendai 980-8575, Japan.

ABSTRACT
Glycogen synthase kinase-3 beta (GSK-3β) has been investigated as a therapeutic target for numerous human diseases including cancer because of their diverse cellular functions. Although GSK-3β inhibitors have been investigated as anticancer reagents, precise biological mechanisms remain to be determined. In this study, we investigated the anticancer effects of GSK-3β inhibitors on cancer cell lines and observed centrosome dysregulation which resulted in abnormal mitosis. Mitotic checkpoints sensed the mitotic abnormalities and induced apoptosis. For cells that were inherently resistant to apoptosis, cell death distinct from apoptosis was induced. After GSK-3β inhibitor treatment, these cells exhibited characteristic features of mitotic catastrophe, including distended and multivesiculated nuclei and inappropriate reductions in cyclin B1 expression. This suggested that mitotic catastrophe was an alternative mechanism in cells resistant to apoptosis. Although the role of GSK-3β in centrosomes has not yet been clarified, phosphorylated GSK-3β was localised in centrosomes. From these data, GSK-3β seems to regulate centrosome function. Thus, we propose that centrosome dysregulation is an important mechanism for the anticancer effects of GSK-3β inhibitors and that mitotic catastrophe serves as a safe-guard system to remove cells with any mitotic abnormalities induced by GSK-3β inhibition.

No MeSH data available.


Related in: MedlinePlus

Chromosomal instability induced by AR-A0114418.(a) Representative plots of cellular DNA contents in RKO cells analysed by flow cytometry. Cells were analysed at the indicated times after adding 20 μM AR-A014418. Signal peaks indicate maximum DNA densities in each cell. Areas under the curve (AUC) of the signal indicate the total DNA contents in each cell. The ratio of the signal peak to AUC of the signal is an indicator of particle aggregation. When cells make aggregates, the AUC of the signal increases whereas the signal peak does not. (b) Increases in DNA contents after treatment with AR-A014418. Peak signal intensity of G0/G1 phase in DNA histogram was measured as a DNA content after 120 h treatment with 20 μM AR-A0114418. Average of three independent experiments is shown. Error bars indicate 95% CIs (*p < 0.05). (c) Mitotic spindle morphology after AR-A014418. Cells were treated with 20 μM AR-A014418 for 48 h and then stained. (Scale bar = 10 μm).
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f4: Chromosomal instability induced by AR-A0114418.(a) Representative plots of cellular DNA contents in RKO cells analysed by flow cytometry. Cells were analysed at the indicated times after adding 20 μM AR-A014418. Signal peaks indicate maximum DNA densities in each cell. Areas under the curve (AUC) of the signal indicate the total DNA contents in each cell. The ratio of the signal peak to AUC of the signal is an indicator of particle aggregation. When cells make aggregates, the AUC of the signal increases whereas the signal peak does not. (b) Increases in DNA contents after treatment with AR-A014418. Peak signal intensity of G0/G1 phase in DNA histogram was measured as a DNA content after 120 h treatment with 20 μM AR-A0114418. Average of three independent experiments is shown. Error bars indicate 95% CIs (*p < 0.05). (c) Mitotic spindle morphology after AR-A014418. Cells were treated with 20 μM AR-A014418 for 48 h and then stained. (Scale bar = 10 μm).

Mentions: To determine the mechanism underlying the antiproliferative effects of the GSK-3β inhibitor, the DNA histograms were analysed further. In addition to the changes in cell cycle distributions, cell fraction peaks were shifted towards higher DNA contents after 72 h treatment with 20 μM AR-A0114418 (Fig. 4a). Except for KPK13 cells, there were significant increases in the cellular DNA contents in all cell lines after 120 h treatment with AR-A0114418 (Fig. 4b). FISH analysis using probes specific for chromosomes 17 and 20 showed random amplification of these chromosomes after treatment with 20 μM AR-A0114418, which suggested chromosomal instability (Supplementary Fig. S3).


Inhibition of glycogen synthase kinase-3 beta induces apoptosis and mitotic catastrophe by disrupting centrosome regulation in cancer cells.

Yoshino Y, Ishioka C - Sci Rep (2015)

Chromosomal instability induced by AR-A0114418.(a) Representative plots of cellular DNA contents in RKO cells analysed by flow cytometry. Cells were analysed at the indicated times after adding 20 μM AR-A014418. Signal peaks indicate maximum DNA densities in each cell. Areas under the curve (AUC) of the signal indicate the total DNA contents in each cell. The ratio of the signal peak to AUC of the signal is an indicator of particle aggregation. When cells make aggregates, the AUC of the signal increases whereas the signal peak does not. (b) Increases in DNA contents after treatment with AR-A014418. Peak signal intensity of G0/G1 phase in DNA histogram was measured as a DNA content after 120 h treatment with 20 μM AR-A0114418. Average of three independent experiments is shown. Error bars indicate 95% CIs (*p < 0.05). (c) Mitotic spindle morphology after AR-A014418. Cells were treated with 20 μM AR-A014418 for 48 h and then stained. (Scale bar = 10 μm).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543981&req=5

f4: Chromosomal instability induced by AR-A0114418.(a) Representative plots of cellular DNA contents in RKO cells analysed by flow cytometry. Cells were analysed at the indicated times after adding 20 μM AR-A014418. Signal peaks indicate maximum DNA densities in each cell. Areas under the curve (AUC) of the signal indicate the total DNA contents in each cell. The ratio of the signal peak to AUC of the signal is an indicator of particle aggregation. When cells make aggregates, the AUC of the signal increases whereas the signal peak does not. (b) Increases in DNA contents after treatment with AR-A014418. Peak signal intensity of G0/G1 phase in DNA histogram was measured as a DNA content after 120 h treatment with 20 μM AR-A0114418. Average of three independent experiments is shown. Error bars indicate 95% CIs (*p < 0.05). (c) Mitotic spindle morphology after AR-A014418. Cells were treated with 20 μM AR-A014418 for 48 h and then stained. (Scale bar = 10 μm).
Mentions: To determine the mechanism underlying the antiproliferative effects of the GSK-3β inhibitor, the DNA histograms were analysed further. In addition to the changes in cell cycle distributions, cell fraction peaks were shifted towards higher DNA contents after 72 h treatment with 20 μM AR-A0114418 (Fig. 4a). Except for KPK13 cells, there were significant increases in the cellular DNA contents in all cell lines after 120 h treatment with AR-A0114418 (Fig. 4b). FISH analysis using probes specific for chromosomes 17 and 20 showed random amplification of these chromosomes after treatment with 20 μM AR-A0114418, which suggested chromosomal instability (Supplementary Fig. S3).

Bottom Line: After GSK-3β inhibitor treatment, these cells exhibited characteristic features of mitotic catastrophe, including distended and multivesiculated nuclei and inappropriate reductions in cyclin B1 expression.From these data, GSK-3β seems to regulate centrosome function.Thus, we propose that centrosome dysregulation is an important mechanism for the anticancer effects of GSK-3β inhibitors and that mitotic catastrophe serves as a safe-guard system to remove cells with any mitotic abnormalities induced by GSK-3β inhibition.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Oncology, Institute of Development, Aging and Cancer, Tohoku University, Seiryo-machi 4-1, Aoba-ku, Sendai 980-8575, Japan.

ABSTRACT
Glycogen synthase kinase-3 beta (GSK-3β) has been investigated as a therapeutic target for numerous human diseases including cancer because of their diverse cellular functions. Although GSK-3β inhibitors have been investigated as anticancer reagents, precise biological mechanisms remain to be determined. In this study, we investigated the anticancer effects of GSK-3β inhibitors on cancer cell lines and observed centrosome dysregulation which resulted in abnormal mitosis. Mitotic checkpoints sensed the mitotic abnormalities and induced apoptosis. For cells that were inherently resistant to apoptosis, cell death distinct from apoptosis was induced. After GSK-3β inhibitor treatment, these cells exhibited characteristic features of mitotic catastrophe, including distended and multivesiculated nuclei and inappropriate reductions in cyclin B1 expression. This suggested that mitotic catastrophe was an alternative mechanism in cells resistant to apoptosis. Although the role of GSK-3β in centrosomes has not yet been clarified, phosphorylated GSK-3β was localised in centrosomes. From these data, GSK-3β seems to regulate centrosome function. Thus, we propose that centrosome dysregulation is an important mechanism for the anticancer effects of GSK-3β inhibitors and that mitotic catastrophe serves as a safe-guard system to remove cells with any mitotic abnormalities induced by GSK-3β inhibition.

No MeSH data available.


Related in: MedlinePlus