Limits...
8‑bromo‑7‑methoxychrysin induces apoptosis by regulating Akt/FOXO3a pathway in cisplatin‑sensitive and resistant ovarian cancer cells.

Ding Q, Chen Y, Zhang Q, Guo Y, Huang Z, Dai L, Cao S - Mol Med Rep (2015)

Bottom Line: 8‑bromo‑7‑methoxychrysin (BrMC), a novel chrysin analog, was reported to have anti‑cancer activities.BrMC‑induced apoptotic cell death occurred mainly by the activation of Akt, which was accompanied by the overexpression of transcription factor FOXO3a, with a concomitant increase in the expression levels of Bim.Silencing Bim expression by using small interfering RNA, attenuated the induction of apoptosis by BrMC treatment.

View Article: PubMed Central - PubMed

Affiliation: Hunan University of Traditional Chinese Medicine, Changsha, Hunan 410208, P.R.China.

ABSTRACT
8‑bromo‑7‑methoxychrysin (BrMC), a novel chrysin analog, was reported to have anti‑cancer activities. The aim of the present study was to investigate the molecular mechanism of 8‑bromo‑7‑methoxychrysin (BrMC)‑induced apoptosis via the Akt/forkhead box O3a (FOXO3a) pathway in cisplatin (DDP)‑sensitive and ‑resistant ovarian cancer cells. The human ovarian cancer cell lines A2780 and A2780/DDP were cultured in vitro. Various molecular techniques were used to assess the expression of FOXO3a and B cell lymphoma 2 (Bcl‑2)‑interacting mediator of cell death (Bim) in cisplatin‑sensitive and ‑resistant ovarian cancer cells. Different concentrations of BrMC induced apoptosis in cisplatin‑sensitive and ‑resistant ovarian cancer cells. BrMC‑induced apoptotic cell death occurred mainly by the activation of Akt, which was accompanied by the overexpression of transcription factor FOXO3a, with a concomitant increase in the expression levels of Bim. Silencing Bim expression by using small interfering RNA, attenuated the induction of apoptosis by BrMC treatment. The results indicated that BrMC‑induced apoptosis in cisplatin‑sensitive and ‑resistant ovarian cancer cells may occur via the regulation of Akt/FOXO3a, leading to Bim transcription.

Show MeSH

Related in: MedlinePlus

FOXO3a protein mediates Bim activation in ovarian cancer cells. Western blot analysis of (A) A2780 and (B) A2780/DDP cells treated with BRMC for 24 h. The expression of p-FOXO3a, t-FOXO3a and Bim was analyzed and β-actin was used as a loading control. (C and D) Cells were transiently transfected with a control non-specific siRNA or FOXO3a-specific siRNA for 48 h and treated with or without BrMC for 24 h. Cell lysates were obtained and assayed for FOXO3a and Bim by western blot. (E) Effect of Bim-siRNA on Akt phosphorylation. Cells were transfected with a control non-specific siRNA or Bim-specific siRNA for 48 h and were exposed to BrMC for 24 h. All data are representative of three independent experiments. (F) Effects of Bim-siRNA on the apoptotic rate of the A2780 and A2780/DDP cells. All data are depicted graphically as the mean ± standard error of the mean for at least three independent experiments. *P<0.05, **P<0.01, vs. apoptotic rate of the A2780 and A2780/DDP cells treated with siRNA alone; #P<0.05, vs. treatment with BrMC (5 µm) and Bim siRNA.. p/t-FOXO3a, phosphorylated/total forkhead box O3a; BrMC, 8-bromo-7-methoxychrysin; Bim, Bcl2-interacting mediator of cell death; siRNA, small interfering RNA; DDP, cisplatin; Cont, control; BIM, bim-specific siRNA; z-DEVD-fmk, Caspase-3 specific inhibitor Z-Asp-Glu-Val-Asp-CH2F.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4581817&req=5

f4-mmr-12-04-5100: FOXO3a protein mediates Bim activation in ovarian cancer cells. Western blot analysis of (A) A2780 and (B) A2780/DDP cells treated with BRMC for 24 h. The expression of p-FOXO3a, t-FOXO3a and Bim was analyzed and β-actin was used as a loading control. (C and D) Cells were transiently transfected with a control non-specific siRNA or FOXO3a-specific siRNA for 48 h and treated with or without BrMC for 24 h. Cell lysates were obtained and assayed for FOXO3a and Bim by western blot. (E) Effect of Bim-siRNA on Akt phosphorylation. Cells were transfected with a control non-specific siRNA or Bim-specific siRNA for 48 h and were exposed to BrMC for 24 h. All data are representative of three independent experiments. (F) Effects of Bim-siRNA on the apoptotic rate of the A2780 and A2780/DDP cells. All data are depicted graphically as the mean ± standard error of the mean for at least three independent experiments. *P<0.05, **P<0.01, vs. apoptotic rate of the A2780 and A2780/DDP cells treated with siRNA alone; #P<0.05, vs. treatment with BrMC (5 µm) and Bim siRNA.. p/t-FOXO3a, phosphorylated/total forkhead box O3a; BrMC, 8-bromo-7-methoxychrysin; Bim, Bcl2-interacting mediator of cell death; siRNA, small interfering RNA; DDP, cisplatin; Cont, control; BIM, bim-specific siRNA; z-DEVD-fmk, Caspase-3 specific inhibitor Z-Asp-Glu-Val-Asp-CH2F.

Mentions: Akt mediates Bim activation via two primary pathways: (1) Akt phosphorylates Bim directly and inhibits Bim activation (34,35); (2) Akt phosphorylates FOXO3A, leading to its cytoplasmic retention by 14-3-3 proteins (11,37). This prevents FOXO3a translocation to the nucleus to induce Bim transcription, demonstrating that Akt indirectly regulates Bim activation. Therefore, the effect of BrMC on FOXO3a phosphorylation was examined. Fig. 4A and B, demonstrate the dose-dependent inhibition of FOXO3a phosphorylation by BrMC. As phosphorylation suppresses the transcriptional activity of FOXO3a, the expression of Bim was subsequently examined. As shown in Fig. 4A and B, in parallel with reduced FOXO phosphorylation, Bim was upregulated in response to BrMC treatment in A2780 and A2780/DDP cells.


8‑bromo‑7‑methoxychrysin induces apoptosis by regulating Akt/FOXO3a pathway in cisplatin‑sensitive and resistant ovarian cancer cells.

Ding Q, Chen Y, Zhang Q, Guo Y, Huang Z, Dai L, Cao S - Mol Med Rep (2015)

FOXO3a protein mediates Bim activation in ovarian cancer cells. Western blot analysis of (A) A2780 and (B) A2780/DDP cells treated with BRMC for 24 h. The expression of p-FOXO3a, t-FOXO3a and Bim was analyzed and β-actin was used as a loading control. (C and D) Cells were transiently transfected with a control non-specific siRNA or FOXO3a-specific siRNA for 48 h and treated with or without BrMC for 24 h. Cell lysates were obtained and assayed for FOXO3a and Bim by western blot. (E) Effect of Bim-siRNA on Akt phosphorylation. Cells were transfected with a control non-specific siRNA or Bim-specific siRNA for 48 h and were exposed to BrMC for 24 h. All data are representative of three independent experiments. (F) Effects of Bim-siRNA on the apoptotic rate of the A2780 and A2780/DDP cells. All data are depicted graphically as the mean ± standard error of the mean for at least three independent experiments. *P<0.05, **P<0.01, vs. apoptotic rate of the A2780 and A2780/DDP cells treated with siRNA alone; #P<0.05, vs. treatment with BrMC (5 µm) and Bim siRNA.. p/t-FOXO3a, phosphorylated/total forkhead box O3a; BrMC, 8-bromo-7-methoxychrysin; Bim, Bcl2-interacting mediator of cell death; siRNA, small interfering RNA; DDP, cisplatin; Cont, control; BIM, bim-specific siRNA; z-DEVD-fmk, Caspase-3 specific inhibitor Z-Asp-Glu-Val-Asp-CH2F.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581817&req=5

f4-mmr-12-04-5100: FOXO3a protein mediates Bim activation in ovarian cancer cells. Western blot analysis of (A) A2780 and (B) A2780/DDP cells treated with BRMC for 24 h. The expression of p-FOXO3a, t-FOXO3a and Bim was analyzed and β-actin was used as a loading control. (C and D) Cells were transiently transfected with a control non-specific siRNA or FOXO3a-specific siRNA for 48 h and treated with or without BrMC for 24 h. Cell lysates were obtained and assayed for FOXO3a and Bim by western blot. (E) Effect of Bim-siRNA on Akt phosphorylation. Cells were transfected with a control non-specific siRNA or Bim-specific siRNA for 48 h and were exposed to BrMC for 24 h. All data are representative of three independent experiments. (F) Effects of Bim-siRNA on the apoptotic rate of the A2780 and A2780/DDP cells. All data are depicted graphically as the mean ± standard error of the mean for at least three independent experiments. *P<0.05, **P<0.01, vs. apoptotic rate of the A2780 and A2780/DDP cells treated with siRNA alone; #P<0.05, vs. treatment with BrMC (5 µm) and Bim siRNA.. p/t-FOXO3a, phosphorylated/total forkhead box O3a; BrMC, 8-bromo-7-methoxychrysin; Bim, Bcl2-interacting mediator of cell death; siRNA, small interfering RNA; DDP, cisplatin; Cont, control; BIM, bim-specific siRNA; z-DEVD-fmk, Caspase-3 specific inhibitor Z-Asp-Glu-Val-Asp-CH2F.
Mentions: Akt mediates Bim activation via two primary pathways: (1) Akt phosphorylates Bim directly and inhibits Bim activation (34,35); (2) Akt phosphorylates FOXO3A, leading to its cytoplasmic retention by 14-3-3 proteins (11,37). This prevents FOXO3a translocation to the nucleus to induce Bim transcription, demonstrating that Akt indirectly regulates Bim activation. Therefore, the effect of BrMC on FOXO3a phosphorylation was examined. Fig. 4A and B, demonstrate the dose-dependent inhibition of FOXO3a phosphorylation by BrMC. As phosphorylation suppresses the transcriptional activity of FOXO3a, the expression of Bim was subsequently examined. As shown in Fig. 4A and B, in parallel with reduced FOXO phosphorylation, Bim was upregulated in response to BrMC treatment in A2780 and A2780/DDP cells.

Bottom Line: 8‑bromo‑7‑methoxychrysin (BrMC), a novel chrysin analog, was reported to have anti‑cancer activities.BrMC‑induced apoptotic cell death occurred mainly by the activation of Akt, which was accompanied by the overexpression of transcription factor FOXO3a, with a concomitant increase in the expression levels of Bim.Silencing Bim expression by using small interfering RNA, attenuated the induction of apoptosis by BrMC treatment.

View Article: PubMed Central - PubMed

Affiliation: Hunan University of Traditional Chinese Medicine, Changsha, Hunan 410208, P.R.China.

ABSTRACT
8‑bromo‑7‑methoxychrysin (BrMC), a novel chrysin analog, was reported to have anti‑cancer activities. The aim of the present study was to investigate the molecular mechanism of 8‑bromo‑7‑methoxychrysin (BrMC)‑induced apoptosis via the Akt/forkhead box O3a (FOXO3a) pathway in cisplatin (DDP)‑sensitive and ‑resistant ovarian cancer cells. The human ovarian cancer cell lines A2780 and A2780/DDP were cultured in vitro. Various molecular techniques were used to assess the expression of FOXO3a and B cell lymphoma 2 (Bcl‑2)‑interacting mediator of cell death (Bim) in cisplatin‑sensitive and ‑resistant ovarian cancer cells. Different concentrations of BrMC induced apoptosis in cisplatin‑sensitive and ‑resistant ovarian cancer cells. BrMC‑induced apoptotic cell death occurred mainly by the activation of Akt, which was accompanied by the overexpression of transcription factor FOXO3a, with a concomitant increase in the expression levels of Bim. Silencing Bim expression by using small interfering RNA, attenuated the induction of apoptosis by BrMC treatment. The results indicated that BrMC‑induced apoptosis in cisplatin‑sensitive and ‑resistant ovarian cancer cells may occur via the regulation of Akt/FOXO3a, leading to Bim transcription.

Show MeSH
Related in: MedlinePlus