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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

Effects of AR-A014418 on normal cells.(a) Cell cycle distributions of HUVEC cells. Cells were analysed after treatment with DMSO or 20 μM AR-A014418 for 96 h. Average of three independent experiments is shown. (b) Changes in cellular DNA contents after treatment with 20 μM AR-A014418 for 96 h. Error bars indicate 95% CIs. (c) Frequency of abnormal centrosomes. Cells were stained after treatment with AR-A014418 (20 μM), GSK-3β inhibitor XXVI (10 μM), or lithium chloride (50 mM) for 42 h. At least 100 cells were examined in each sample. CIs and p-values were calculated by Fisher’s exact test. Error bars indicate 95% CIs. (d) Schematic overview of cellular responses to GSK-3β inhibition.
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f7: Effects of AR-A014418 on normal cells.(a) Cell cycle distributions of HUVEC cells. Cells were analysed after treatment with DMSO or 20 μM AR-A014418 for 96 h. Average of three independent experiments is shown. (b) Changes in cellular DNA contents after treatment with 20 μM AR-A014418 for 96 h. Error bars indicate 95% CIs. (c) Frequency of abnormal centrosomes. Cells were stained after treatment with AR-A014418 (20 μM), GSK-3β inhibitor XXVI (10 μM), or lithium chloride (50 mM) for 42 h. At least 100 cells were examined in each sample. CIs and p-values were calculated by Fisher’s exact test. Error bars indicate 95% CIs. (d) Schematic overview of cellular responses to GSK-3β inhibition.

Mentions: To investigate if GSK-3β inhibitors induced chromosomal instability in normal cells, we examined cell cycle distributions, cellular DNA contents, and centrosomes in HUVEC cells after treatment with the GSK-3β inhibitors. Cell cycle analysis showed an apparent M-phase arrest in HUVEC cells treated with 20 μM AR-A014418 for 96 h (Fig. 7a). Because longer-term treatment (120 h) resulted in overt cell death, cell cycle distribution was not evaluable (data not shown). An analysis of the cell cycle histograms did not show increase in cellular DNA contents (Fig. 7b). Furthermore, there was no increase in the frequency of cells with abnormal centrosomes after treatment with any of the three GSK-3β inhibitors, AR-A014418, GSK-3β inhibitor XXVI, and lithium chloride (Fig. 7c). Based on these data, GSK-3β inhibitors apparently did not induce any chromosomal instability in HUVEC cells.


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)

Effects of AR-A014418 on normal cells.(a) Cell cycle distributions of HUVEC cells. Cells were analysed after treatment with DMSO or 20 μM AR-A014418 for 96 h. Average of three independent experiments is shown. (b) Changes in cellular DNA contents after treatment with 20 μM AR-A014418 for 96 h. Error bars indicate 95% CIs. (c) Frequency of abnormal centrosomes. Cells were stained after treatment with AR-A014418 (20 μM), GSK-3β inhibitor XXVI (10 μM), or lithium chloride (50 mM) for 42 h. At least 100 cells were examined in each sample. CIs and p-values were calculated by Fisher’s exact test. Error bars indicate 95% CIs. (d) Schematic overview of cellular responses to GSK-3β inhibition.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f7: Effects of AR-A014418 on normal cells.(a) Cell cycle distributions of HUVEC cells. Cells were analysed after treatment with DMSO or 20 μM AR-A014418 for 96 h. Average of three independent experiments is shown. (b) Changes in cellular DNA contents after treatment with 20 μM AR-A014418 for 96 h. Error bars indicate 95% CIs. (c) Frequency of abnormal centrosomes. Cells were stained after treatment with AR-A014418 (20 μM), GSK-3β inhibitor XXVI (10 μM), or lithium chloride (50 mM) for 42 h. At least 100 cells were examined in each sample. CIs and p-values were calculated by Fisher’s exact test. Error bars indicate 95% CIs. (d) Schematic overview of cellular responses to GSK-3β inhibition.
Mentions: To investigate if GSK-3β inhibitors induced chromosomal instability in normal cells, we examined cell cycle distributions, cellular DNA contents, and centrosomes in HUVEC cells after treatment with the GSK-3β inhibitors. Cell cycle analysis showed an apparent M-phase arrest in HUVEC cells treated with 20 μM AR-A014418 for 96 h (Fig. 7a). Because longer-term treatment (120 h) resulted in overt cell death, cell cycle distribution was not evaluable (data not shown). An analysis of the cell cycle histograms did not show increase in cellular DNA contents (Fig. 7b). Furthermore, there was no increase in the frequency of cells with abnormal centrosomes after treatment with any of the three GSK-3β inhibitors, AR-A014418, GSK-3β inhibitor XXVI, and lithium chloride (Fig. 7c). Based on these data, GSK-3β inhibitors apparently did not induce any chromosomal instability in HUVEC cells.

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