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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

The way of cell death induced by AR-A0114418.(a) Protein expression of p53 after AR-A014418 treatment. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. (b) Phospho-STAT3 expression in sensitive cell lines. Band intensities were determined by densitometry and the expression level relative to that in MDA-MB-435S cells was determined. Average of three independent experiments is shown in the right graph. Error bars indicate 95% CIs. (c) Morphology of nuclei in MDA-MB-435S after AR-A0114418 treatment. Cells were fixed and stained with DAPI after 48 h treatment with 20 μM AR-A014418. (Scale bar = 10 μm) (d) Protein expression of cyclin B1. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. Right graph shows relative cyclin B1 expression compared with control after 72 h treatment. Average of three independent experiments is shown. Error bars indicate 95% CIs. (*p < 0.001).
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f6: The way of cell death induced by AR-A0114418.(a) Protein expression of p53 after AR-A014418 treatment. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. (b) Phospho-STAT3 expression in sensitive cell lines. Band intensities were determined by densitometry and the expression level relative to that in MDA-MB-435S cells was determined. Average of three independent experiments is shown in the right graph. Error bars indicate 95% CIs. (c) Morphology of nuclei in MDA-MB-435S after AR-A0114418 treatment. Cells were fixed and stained with DAPI after 48 h treatment with 20 μM AR-A014418. (Scale bar = 10 μm) (d) Protein expression of cyclin B1. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. Right graph shows relative cyclin B1 expression compared with control after 72 h treatment. Average of three independent experiments is shown. Error bars indicate 95% CIs. (*p < 0.001).

Mentions: The biochemical markers of apoptosis, including cleavage of caspases and PARP, were observed in HCT 116 and RKO cells but not in MDA-MB-435S cells. As a cause of this difference, we first focused on p53 status. HCT 116 and RKO cells have wild-type p53, whereas MDA-MB-435S cells have mutant p53333435. In fact, treatment with 20 μM AR-A014418 increased the p53 protein levels by 48 h after adding of AR-A0114418 in HCT 116 and RKO cells but not in MDA-MB-435S cells (Fig. 6a). Insensitive cell lines, SUIT-2 and KPK13 did not increase p53 expression after AR-A0114418 treatment (Fig. 6a). In addition, phosphorylated STAT3, which negatively regulates apoptosis, was expressed at significantly higher levels in MDA-MB-435S cells than in HCT 116 and RKO cells (Fig. 6b). Based on these data, it was suggested that MDA-MB-435S was resistant to apoptosis that should be induced by centrosome aberration after GSK-3β inhibition.


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)

The way of cell death induced by AR-A0114418.(a) Protein expression of p53 after AR-A014418 treatment. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. (b) Phospho-STAT3 expression in sensitive cell lines. Band intensities were determined by densitometry and the expression level relative to that in MDA-MB-435S cells was determined. Average of three independent experiments is shown in the right graph. Error bars indicate 95% CIs. (c) Morphology of nuclei in MDA-MB-435S after AR-A0114418 treatment. Cells were fixed and stained with DAPI after 48 h treatment with 20 μM AR-A014418. (Scale bar = 10 μm) (d) Protein expression of cyclin B1. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. Right graph shows relative cyclin B1 expression compared with control after 72 h treatment. Average of three independent experiments is shown. Error bars indicate 95% CIs. (*p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4543981&req=5

f6: The way of cell death induced by AR-A0114418.(a) Protein expression of p53 after AR-A014418 treatment. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. (b) Phospho-STAT3 expression in sensitive cell lines. Band intensities were determined by densitometry and the expression level relative to that in MDA-MB-435S cells was determined. Average of three independent experiments is shown in the right graph. Error bars indicate 95% CIs. (c) Morphology of nuclei in MDA-MB-435S after AR-A0114418 treatment. Cells were fixed and stained with DAPI after 48 h treatment with 20 μM AR-A014418. (Scale bar = 10 μm) (d) Protein expression of cyclin B1. Cells were harvested for western blot after treatment with 20 μM AR-A014418 for indicated periods. Right graph shows relative cyclin B1 expression compared with control after 72 h treatment. Average of three independent experiments is shown. Error bars indicate 95% CIs. (*p < 0.001).
Mentions: The biochemical markers of apoptosis, including cleavage of caspases and PARP, were observed in HCT 116 and RKO cells but not in MDA-MB-435S cells. As a cause of this difference, we first focused on p53 status. HCT 116 and RKO cells have wild-type p53, whereas MDA-MB-435S cells have mutant p53333435. In fact, treatment with 20 μM AR-A014418 increased the p53 protein levels by 48 h after adding of AR-A0114418 in HCT 116 and RKO cells but not in MDA-MB-435S cells (Fig. 6a). Insensitive cell lines, SUIT-2 and KPK13 did not increase p53 expression after AR-A0114418 treatment (Fig. 6a). In addition, phosphorylated STAT3, which negatively regulates apoptosis, was expressed at significantly higher levels in MDA-MB-435S cells than in HCT 116 and RKO cells (Fig. 6b). Based on these data, it was suggested that MDA-MB-435S was resistant to apoptosis that should be induced by centrosome aberration after GSK-3β inhibition.

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