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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

Cell cycle changes and apoptosis induction after AR-A014418.(a) Changes in cell cycle distribution after AR-A014418 treatment. Cells were analysed by flow cytometry after treatment with 20 μM AR-A014418 for 120 h. Average of three independent experiments is shown. (b) Representative DNA histograms of HCT 116 and KPK13 after 120 h treatment with 20 μM AR-A0114418. Red lines indicate peaks of G0/G1 population in control samples. (c) Sub-G1 fractions of cells lines after AR-A0114418 treatment. Cells were analysed after treatment with 20 μM AR-A0114418 for 120 h. Sub-G1 fractions increased for all cell lines except for KPK13 cells. Error bars indicate 95% CIs (*p < 0.05). (d,e,f) Western blot of apoptosis related proteins in RKO (d), HCT116 (e), and MDA-MB-435S (f). Cells were treated with 20 μM AR-A0114418 for indicated periods.
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f2: Cell cycle changes and apoptosis induction after AR-A014418.(a) Changes in cell cycle distribution after AR-A014418 treatment. Cells were analysed by flow cytometry after treatment with 20 μM AR-A014418 for 120 h. Average of three independent experiments is shown. (b) Representative DNA histograms of HCT 116 and KPK13 after 120 h treatment with 20 μM AR-A0114418. Red lines indicate peaks of G0/G1 population in control samples. (c) Sub-G1 fractions of cells lines after AR-A0114418 treatment. Cells were analysed after treatment with 20 μM AR-A0114418 for 120 h. Sub-G1 fractions increased for all cell lines except for KPK13 cells. Error bars indicate 95% CIs (*p < 0.05). (d,e,f) Western blot of apoptosis related proteins in RKO (d), HCT116 (e), and MDA-MB-435S (f). Cells were treated with 20 μM AR-A0114418 for indicated periods.

Mentions: To clarify what type of cell death occurred, we examined cell cycle distributions and apoptosis-related protein expression after AR-A0114418 treatment. Cell cycle distributions were analysed after long-term (120 h) treatment with AR-A014418 at 20 μM, which was sufficiently higher than IC50s of three sensitive cell lines. AR-A014418 treatment significantly increased the S phase fraction and correspondingly reduced the G0/G1 phase fraction for all cell lines, which indicated cell cycle arrest at promotion to M phase (Fig. 2a). Figure 2b shows representative DNA histograms of sensitive and insensitive cell lines, HCT 116 and KPK13, respectively. AR-A014418 treatment also increased the sub-G1 fraction for all cell lines, except for KPK13 cells (Fig. 2c).


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)

Cell cycle changes and apoptosis induction after AR-A014418.(a) Changes in cell cycle distribution after AR-A014418 treatment. Cells were analysed by flow cytometry after treatment with 20 μM AR-A014418 for 120 h. Average of three independent experiments is shown. (b) Representative DNA histograms of HCT 116 and KPK13 after 120 h treatment with 20 μM AR-A0114418. Red lines indicate peaks of G0/G1 population in control samples. (c) Sub-G1 fractions of cells lines after AR-A0114418 treatment. Cells were analysed after treatment with 20 μM AR-A0114418 for 120 h. Sub-G1 fractions increased for all cell lines except for KPK13 cells. Error bars indicate 95% CIs (*p < 0.05). (d,e,f) Western blot of apoptosis related proteins in RKO (d), HCT116 (e), and MDA-MB-435S (f). Cells were treated with 20 μM AR-A0114418 for indicated periods.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Cell cycle changes and apoptosis induction after AR-A014418.(a) Changes in cell cycle distribution after AR-A014418 treatment. Cells were analysed by flow cytometry after treatment with 20 μM AR-A014418 for 120 h. Average of three independent experiments is shown. (b) Representative DNA histograms of HCT 116 and KPK13 after 120 h treatment with 20 μM AR-A0114418. Red lines indicate peaks of G0/G1 population in control samples. (c) Sub-G1 fractions of cells lines after AR-A0114418 treatment. Cells were analysed after treatment with 20 μM AR-A0114418 for 120 h. Sub-G1 fractions increased for all cell lines except for KPK13 cells. Error bars indicate 95% CIs (*p < 0.05). (d,e,f) Western blot of apoptosis related proteins in RKO (d), HCT116 (e), and MDA-MB-435S (f). Cells were treated with 20 μM AR-A0114418 for indicated periods.
Mentions: To clarify what type of cell death occurred, we examined cell cycle distributions and apoptosis-related protein expression after AR-A0114418 treatment. Cell cycle distributions were analysed after long-term (120 h) treatment with AR-A014418 at 20 μM, which was sufficiently higher than IC50s of three sensitive cell lines. AR-A014418 treatment significantly increased the S phase fraction and correspondingly reduced the G0/G1 phase fraction for all cell lines, which indicated cell cycle arrest at promotion to M phase (Fig. 2a). Figure 2b shows representative DNA histograms of sensitive and insensitive cell lines, HCT 116 and KPK13, respectively. AR-A014418 treatment also increased the sub-G1 fraction for all cell lines, except for KPK13 cells (Fig. 2c).

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