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Induction of apoptosis and autophagy via sirtuin1- and PI3K/Akt/mTOR-mediated pathways by plumbagin in human prostate cancer cells.

Zhou ZW, Li XX, He ZX, Pan ST, Yang Y, Zhang X, Chow K, Yang T, Qiu JX, Zhou Q, Tan J, Wang D, Zhou SF - Drug Des Devel Ther (2015)

Bottom Line: Our study has shown that PLB had potent pro-apoptotic and pro-autophagic effects on PC-3 and DU145 cells.In addition, PLB downregulated pre-B cell colony-enhancing factor/visfatin, and the inhibition of pre-B cell colony-enhancing factor/visfatin significantly enhanced basal and PLB-induced apoptosis and autophagy in both cell lines.Moreover, reduction of intracellular reactive oxygen species (ROS) level attenuated the apoptosis- and autophagy-inducing effects of PLB on both PC-3 and DU145 cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA ; Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, People's Republic of China.

ABSTRACT
Plumbagin (PLB) has been shown to have anticancer activities in animal models, but the role of PLB in prostate cancer treatment is unclear. This study aimed to investigate the effects of PLB on apoptosis and autophagy and the underlying mechanisms in human prostate cancer cell lines PC-3 and DU145. Our study has shown that PLB had potent pro-apoptotic and pro-autophagic effects on PC-3 and DU145 cells. PLB induced mitochondria-mediated apoptosis and autophagy in concentration- and time-dependent manners in both PC-3 and DU145 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (MAPK) pathways and activation of 5'-AMP-dependent kinase (AMPK) as indicated by their altered phosphorylation, contributing to the pro-autophagic activity of PLB. Modulation of autophagy altered basal and PLB-induced apoptosis in both cell lines. Furthermore, PLB downregulated sirtuin 1 (Sirt1), and inhibition of Sirt1 enhanced autophagy, whereas the induction of Sirt1 abolished PLB-induced autophagy in PC-3 and DU145 cells. In addition, PLB downregulated pre-B cell colony-enhancing factor/visfatin, and the inhibition of pre-B cell colony-enhancing factor/visfatin significantly enhanced basal and PLB-induced apoptosis and autophagy in both cell lines. Moreover, reduction of intracellular reactive oxygen species (ROS) level attenuated the apoptosis- and autophagy-inducing effects of PLB on both PC-3 and DU145 cells. These findings indicate that PLB promotes apoptosis and autophagy in prostate cancer cells via Sirt1- and PI3K/Akt/mTOR-mediated pathways with contribution from AMPK-, p38 MAPK-, visfatin-, and ROS-associated pathways.

No MeSH data available.


Related in: MedlinePlus

Effect of a series of inducers and inhibitors on the apoptosis and autophagy induced by PLB in PC-3 and DU145 cells.Notes: (A) Plots from flow cytometry showing the effects of various compounds on basal and PLB-induced apoptosis in PC-3 and DU145 cells. (B) Plots from flow cytometry showing the effects of the compounds on basal and PLB-induced autophagy in PC-3 and DU145 cells. (C) Bar graphs showing the effects of various compounds on the apoptosis and autophagy in PC-3 and DU145 cells. The cells were pretreated with each of the compounds for 1 hour, and PLB was added and incubated for a further 24 hours. To detect cellular apoptosis, annexin V:PE and 7-AAD were used for double staining after the cells were treated with PLB. The autophagy was detected using the Cyto-ID® green fluorescent dye to stain autophagy-associated vacuoles. Data are the mean ± SD of three independent experiments. *P<0.05; **P<0.01; ***P<0.001 by one-way ANOVA.Abbreviations: ANOVA, analysis of variance; DMSO, dimethylsulfoxide; PLB, plumbagin; SD, standard deviation; WM, wortmannin; 7-AAD, 7-aminoactinomycin D; PE, phycoerythrin.
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f6-dddt-9-1511: Effect of a series of inducers and inhibitors on the apoptosis and autophagy induced by PLB in PC-3 and DU145 cells.Notes: (A) Plots from flow cytometry showing the effects of various compounds on basal and PLB-induced apoptosis in PC-3 and DU145 cells. (B) Plots from flow cytometry showing the effects of the compounds on basal and PLB-induced autophagy in PC-3 and DU145 cells. (C) Bar graphs showing the effects of various compounds on the apoptosis and autophagy in PC-3 and DU145 cells. The cells were pretreated with each of the compounds for 1 hour, and PLB was added and incubated for a further 24 hours. To detect cellular apoptosis, annexin V:PE and 7-AAD were used for double staining after the cells were treated with PLB. The autophagy was detected using the Cyto-ID® green fluorescent dye to stain autophagy-associated vacuoles. Data are the mean ± SD of three independent experiments. *P<0.05; **P<0.01; ***P<0.001 by one-way ANOVA.Abbreviations: ANOVA, analysis of variance; DMSO, dimethylsulfoxide; PLB, plumbagin; SD, standard deviation; WM, wortmannin; 7-AAD, 7-aminoactinomycin D; PE, phycoerythrin.

Mentions: To further examine the crosstalk between apoptosis and autophagy in PC-3 and DU145 cells treated with PLB, we simultaneously determined cellular apoptosis and autophagy using a flow cytometer. As shown in Figure 6A, B, and C, the percentage of basal apoptosis and autophagy in both PC-3 and DU145 cells ranged from 2.8% to 4.7%. Incubation of PC-3 cells with PLB induced both apoptosis and autophagy. In DU145 cells, PLB exhibited a predominant effect on autophagy induction. The ratio of autophagy over apoptosis in PC-3 cells treated with PLB was slightly higher than that in the control cells. The sum of apoptosis plus autophagy increased from 9.9% at basal level to 17.0%, 16.9%, and 19.0% when PC-3 cells were treated with 0.1 μM, 1 μM, and 5 μM PLB, respectively. In DU145 cells, 5 μM PLB increased the ratio of autophagy over apoptosis 2.4-fold (P<0.05). The sum of apoptosis plus autophagy increased from 4.9% at basal level to 4.5%, 5.5%, and 14.7% when DU145 cells were treated with 0.1 μM, 1 μM, and 5 μM PLB for 24 hours, respectively (Figure 6A and B). In addition, when the cells were treated with 5 μM for 12 hours, 24 hours, and 48 hours, the sum of apoptosis plus autophagy increased from 9.6% at basal level to 11.8%, 20.6%, and 49.2% in PC-3 cells (Figure 7). In DU145 cells, the value increased from 13.1% at basal level to 17.2%, 14.8%, 17.1%, and 17.6% when cells were treated for 4 hours, 8 hours, 12 hours, and 48 hours, respectively (Figure 7). The ratio of autophagy over apoptosis increased 2.5-, 3.5-, and 3.5-fold when PC-3 cells were treated with 5 μM PLB for 12 hours, 24 hours, and 48 hours, respectively. In DU145 cells, the ratio of autophagy over apoptosis increased 1.3-, 1.9-, 1.8-, and 1.2-fold when PC-3 cells were treated with 5 μM PLB for 4 hours, 8 hours, 12 hours, and 24 hours, respectively (Figure 7).


Induction of apoptosis and autophagy via sirtuin1- and PI3K/Akt/mTOR-mediated pathways by plumbagin in human prostate cancer cells.

Zhou ZW, Li XX, He ZX, Pan ST, Yang Y, Zhang X, Chow K, Yang T, Qiu JX, Zhou Q, Tan J, Wang D, Zhou SF - Drug Des Devel Ther (2015)

Effect of a series of inducers and inhibitors on the apoptosis and autophagy induced by PLB in PC-3 and DU145 cells.Notes: (A) Plots from flow cytometry showing the effects of various compounds on basal and PLB-induced apoptosis in PC-3 and DU145 cells. (B) Plots from flow cytometry showing the effects of the compounds on basal and PLB-induced autophagy in PC-3 and DU145 cells. (C) Bar graphs showing the effects of various compounds on the apoptosis and autophagy in PC-3 and DU145 cells. The cells were pretreated with each of the compounds for 1 hour, and PLB was added and incubated for a further 24 hours. To detect cellular apoptosis, annexin V:PE and 7-AAD were used for double staining after the cells were treated with PLB. The autophagy was detected using the Cyto-ID® green fluorescent dye to stain autophagy-associated vacuoles. Data are the mean ± SD of three independent experiments. *P<0.05; **P<0.01; ***P<0.001 by one-way ANOVA.Abbreviations: ANOVA, analysis of variance; DMSO, dimethylsulfoxide; PLB, plumbagin; SD, standard deviation; WM, wortmannin; 7-AAD, 7-aminoactinomycin D; PE, phycoerythrin.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4366042&req=5

f6-dddt-9-1511: Effect of a series of inducers and inhibitors on the apoptosis and autophagy induced by PLB in PC-3 and DU145 cells.Notes: (A) Plots from flow cytometry showing the effects of various compounds on basal and PLB-induced apoptosis in PC-3 and DU145 cells. (B) Plots from flow cytometry showing the effects of the compounds on basal and PLB-induced autophagy in PC-3 and DU145 cells. (C) Bar graphs showing the effects of various compounds on the apoptosis and autophagy in PC-3 and DU145 cells. The cells were pretreated with each of the compounds for 1 hour, and PLB was added and incubated for a further 24 hours. To detect cellular apoptosis, annexin V:PE and 7-AAD were used for double staining after the cells were treated with PLB. The autophagy was detected using the Cyto-ID® green fluorescent dye to stain autophagy-associated vacuoles. Data are the mean ± SD of three independent experiments. *P<0.05; **P<0.01; ***P<0.001 by one-way ANOVA.Abbreviations: ANOVA, analysis of variance; DMSO, dimethylsulfoxide; PLB, plumbagin; SD, standard deviation; WM, wortmannin; 7-AAD, 7-aminoactinomycin D; PE, phycoerythrin.
Mentions: To further examine the crosstalk between apoptosis and autophagy in PC-3 and DU145 cells treated with PLB, we simultaneously determined cellular apoptosis and autophagy using a flow cytometer. As shown in Figure 6A, B, and C, the percentage of basal apoptosis and autophagy in both PC-3 and DU145 cells ranged from 2.8% to 4.7%. Incubation of PC-3 cells with PLB induced both apoptosis and autophagy. In DU145 cells, PLB exhibited a predominant effect on autophagy induction. The ratio of autophagy over apoptosis in PC-3 cells treated with PLB was slightly higher than that in the control cells. The sum of apoptosis plus autophagy increased from 9.9% at basal level to 17.0%, 16.9%, and 19.0% when PC-3 cells were treated with 0.1 μM, 1 μM, and 5 μM PLB, respectively. In DU145 cells, 5 μM PLB increased the ratio of autophagy over apoptosis 2.4-fold (P<0.05). The sum of apoptosis plus autophagy increased from 4.9% at basal level to 4.5%, 5.5%, and 14.7% when DU145 cells were treated with 0.1 μM, 1 μM, and 5 μM PLB for 24 hours, respectively (Figure 6A and B). In addition, when the cells were treated with 5 μM for 12 hours, 24 hours, and 48 hours, the sum of apoptosis plus autophagy increased from 9.6% at basal level to 11.8%, 20.6%, and 49.2% in PC-3 cells (Figure 7). In DU145 cells, the value increased from 13.1% at basal level to 17.2%, 14.8%, 17.1%, and 17.6% when cells were treated for 4 hours, 8 hours, 12 hours, and 48 hours, respectively (Figure 7). The ratio of autophagy over apoptosis increased 2.5-, 3.5-, and 3.5-fold when PC-3 cells were treated with 5 μM PLB for 12 hours, 24 hours, and 48 hours, respectively. In DU145 cells, the ratio of autophagy over apoptosis increased 1.3-, 1.9-, 1.8-, and 1.2-fold when PC-3 cells were treated with 5 μM PLB for 4 hours, 8 hours, 12 hours, and 24 hours, respectively (Figure 7).

Bottom Line: Our study has shown that PLB had potent pro-apoptotic and pro-autophagic effects on PC-3 and DU145 cells.In addition, PLB downregulated pre-B cell colony-enhancing factor/visfatin, and the inhibition of pre-B cell colony-enhancing factor/visfatin significantly enhanced basal and PLB-induced apoptosis and autophagy in both cell lines.Moreover, reduction of intracellular reactive oxygen species (ROS) level attenuated the apoptosis- and autophagy-inducing effects of PLB on both PC-3 and DU145 cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA ; Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, People's Republic of China.

ABSTRACT
Plumbagin (PLB) has been shown to have anticancer activities in animal models, but the role of PLB in prostate cancer treatment is unclear. This study aimed to investigate the effects of PLB on apoptosis and autophagy and the underlying mechanisms in human prostate cancer cell lines PC-3 and DU145. Our study has shown that PLB had potent pro-apoptotic and pro-autophagic effects on PC-3 and DU145 cells. PLB induced mitochondria-mediated apoptosis and autophagy in concentration- and time-dependent manners in both PC-3 and DU145 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (MAPK) pathways and activation of 5'-AMP-dependent kinase (AMPK) as indicated by their altered phosphorylation, contributing to the pro-autophagic activity of PLB. Modulation of autophagy altered basal and PLB-induced apoptosis in both cell lines. Furthermore, PLB downregulated sirtuin 1 (Sirt1), and inhibition of Sirt1 enhanced autophagy, whereas the induction of Sirt1 abolished PLB-induced autophagy in PC-3 and DU145 cells. In addition, PLB downregulated pre-B cell colony-enhancing factor/visfatin, and the inhibition of pre-B cell colony-enhancing factor/visfatin significantly enhanced basal and PLB-induced apoptosis and autophagy in both cell lines. Moreover, reduction of intracellular reactive oxygen species (ROS) level attenuated the apoptosis- and autophagy-inducing effects of PLB on both PC-3 and DU145 cells. These findings indicate that PLB promotes apoptosis and autophagy in prostate cancer cells via Sirt1- and PI3K/Akt/mTOR-mediated pathways with contribution from AMPK-, p38 MAPK-, visfatin-, and ROS-associated pathways.

No MeSH data available.


Related in: MedlinePlus