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(-)-Epigallocatechingallate induces apoptosis in B lymphoma cells via caspase-dependent pathway and Bcl-2 family protein modulation.

Wang J, Xie Y, Feng Y, Zhang L, Huang X, Shen X, Luo X - Int. J. Oncol. (2015)

Bottom Line: (-)-Epigallocatechingallate (EGCG) as a representative polyphenol has attracted increasing attention due to its diversified effects, especially its potential as an agent for the prevention or treatment of certain cancers.In agreement, EGCG upregulated the mRNA expression of Fas and Bax while downregulating Bcl-2.Protein expression levels of Bax, activated caspase-3, -7, -8, and -9, and PARP were increased, while Bcl-2 protein levels were reduced by EGCG treatment.

View Article: PubMed Central - PubMed

Affiliation: Research Department, Affiliated Tumour Hospital of Guangxi Medical University, Nanning 530021, P.R. China.

ABSTRACT
(-)-Epigallocatechingallate (EGCG) as a representative polyphenol has attracted increasing attention due to its diversified effects, especially its potential as an agent for the prevention or treatment of certain cancers. However, the molecular mechanisms of EGCG-induced apoptosis in B lymphoma cells are unclear. The aim of this study was to investigate the effect of EGCG on proliferation and apoptosis in the B lymphoma cell lines Jeko-1 and Raji, and determine the underlying mechanisms. Cell proliferation and cytotoxicity were determined by the cell counting kit (CCK-8) assay; apoptosis was assessed by flow cytometry using the Annexin V-PE/7AAD double staining; Fas, Bcl-2 and Bax mRNA expression levels were determined by real-time PCR; caspase activity was measured by the caspase activity assay kit; the expression levels of apoptosis-associated proteins were determined by western blot analysis. We demonstrated that EGCG induced growth inhibition and apoptosis in a dose- and time-dependent manner. In agreement, EGCG upregulated the mRNA expression of Fas and Bax while downregulating Bcl-2. Protein expression levels of Bax, activated caspase-3, -7, -8, and -9, and PARP were increased, while Bcl-2 protein levels were reduced by EGCG treatment. Taken together, EGCG induces B lymphoma cell apoptosis by triggering caspase-dependent intrinsic (mitochondrial) and extrinsic (death receptor) pathways. These findings suggest that EGCG may be a potential agent for the treatment of B lymphoma.

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EGCG increases the activation of caspase-8 and upregulates Fas mRNA levels. (A) Jeko-1 or Raji cells were treated with EGCG at different concentrations (0, 20, 40 and 60 μg/ml) for 24 h. Equal amounts of total protein were analyzed by the caspase-8 colorimetric assay kit, and the activation level is presented by ODexperiment/ODcontrol. (B) The cells were treated as in (A), and Fas mRNA expression was measured by RT-PCR. The relative quantification (RQ) was normalized to GAPDH levels. The values represent mean ± SD from three independent experiments. *p<0.05, compared with the control group (0 μg/ml). #p<0.05, compared with the previous group.
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f5-ijo-46-04-1507: EGCG increases the activation of caspase-8 and upregulates Fas mRNA levels. (A) Jeko-1 or Raji cells were treated with EGCG at different concentrations (0, 20, 40 and 60 μg/ml) for 24 h. Equal amounts of total protein were analyzed by the caspase-8 colorimetric assay kit, and the activation level is presented by ODexperiment/ODcontrol. (B) The cells were treated as in (A), and Fas mRNA expression was measured by RT-PCR. The relative quantification (RQ) was normalized to GAPDH levels. The values represent mean ± SD from three independent experiments. *p<0.05, compared with the control group (0 μg/ml). #p<0.05, compared with the previous group.

Mentions: To explore how the upstream molecules triggered the apoptosis executors caspase-3 and -7, and their substrate PARP, we first determined caspase-8 activity using the caspase colorimetric assay kit. As shown in Fig. 5A EGCG-treated cells showed a dose-dependent increase of caspase-8 activity. Then, to explore the upstream effector that actives caspase-8, the expression of Fas mRNA was assessed by RT-PCR. Fig. 5B showed that Fas mRNA expression levels increased in a dose-dependent manner in EGCG-treated cells. Of note, the maximum caspase-8 activation and Fas mRNA expression levels in Jeko-1 cells were at least doubled compared with controls and significantly higher than in Raji cells. These results suggested that EGCG-induced apoptosis was associated with the death receptor pathway.


(-)-Epigallocatechingallate induces apoptosis in B lymphoma cells via caspase-dependent pathway and Bcl-2 family protein modulation.

Wang J, Xie Y, Feng Y, Zhang L, Huang X, Shen X, Luo X - Int. J. Oncol. (2015)

EGCG increases the activation of caspase-8 and upregulates Fas mRNA levels. (A) Jeko-1 or Raji cells were treated with EGCG at different concentrations (0, 20, 40 and 60 μg/ml) for 24 h. Equal amounts of total protein were analyzed by the caspase-8 colorimetric assay kit, and the activation level is presented by ODexperiment/ODcontrol. (B) The cells were treated as in (A), and Fas mRNA expression was measured by RT-PCR. The relative quantification (RQ) was normalized to GAPDH levels. The values represent mean ± SD from three independent experiments. *p<0.05, compared with the control group (0 μg/ml). #p<0.05, compared with the previous group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4356505&req=5

f5-ijo-46-04-1507: EGCG increases the activation of caspase-8 and upregulates Fas mRNA levels. (A) Jeko-1 or Raji cells were treated with EGCG at different concentrations (0, 20, 40 and 60 μg/ml) for 24 h. Equal amounts of total protein were analyzed by the caspase-8 colorimetric assay kit, and the activation level is presented by ODexperiment/ODcontrol. (B) The cells were treated as in (A), and Fas mRNA expression was measured by RT-PCR. The relative quantification (RQ) was normalized to GAPDH levels. The values represent mean ± SD from three independent experiments. *p<0.05, compared with the control group (0 μg/ml). #p<0.05, compared with the previous group.
Mentions: To explore how the upstream molecules triggered the apoptosis executors caspase-3 and -7, and their substrate PARP, we first determined caspase-8 activity using the caspase colorimetric assay kit. As shown in Fig. 5A EGCG-treated cells showed a dose-dependent increase of caspase-8 activity. Then, to explore the upstream effector that actives caspase-8, the expression of Fas mRNA was assessed by RT-PCR. Fig. 5B showed that Fas mRNA expression levels increased in a dose-dependent manner in EGCG-treated cells. Of note, the maximum caspase-8 activation and Fas mRNA expression levels in Jeko-1 cells were at least doubled compared with controls and significantly higher than in Raji cells. These results suggested that EGCG-induced apoptosis was associated with the death receptor pathway.

Bottom Line: (-)-Epigallocatechingallate (EGCG) as a representative polyphenol has attracted increasing attention due to its diversified effects, especially its potential as an agent for the prevention or treatment of certain cancers.In agreement, EGCG upregulated the mRNA expression of Fas and Bax while downregulating Bcl-2.Protein expression levels of Bax, activated caspase-3, -7, -8, and -9, and PARP were increased, while Bcl-2 protein levels were reduced by EGCG treatment.

View Article: PubMed Central - PubMed

Affiliation: Research Department, Affiliated Tumour Hospital of Guangxi Medical University, Nanning 530021, P.R. China.

ABSTRACT
(-)-Epigallocatechingallate (EGCG) as a representative polyphenol has attracted increasing attention due to its diversified effects, especially its potential as an agent for the prevention or treatment of certain cancers. However, the molecular mechanisms of EGCG-induced apoptosis in B lymphoma cells are unclear. The aim of this study was to investigate the effect of EGCG on proliferation and apoptosis in the B lymphoma cell lines Jeko-1 and Raji, and determine the underlying mechanisms. Cell proliferation and cytotoxicity were determined by the cell counting kit (CCK-8) assay; apoptosis was assessed by flow cytometry using the Annexin V-PE/7AAD double staining; Fas, Bcl-2 and Bax mRNA expression levels were determined by real-time PCR; caspase activity was measured by the caspase activity assay kit; the expression levels of apoptosis-associated proteins were determined by western blot analysis. We demonstrated that EGCG induced growth inhibition and apoptosis in a dose- and time-dependent manner. In agreement, EGCG upregulated the mRNA expression of Fas and Bax while downregulating Bcl-2. Protein expression levels of Bax, activated caspase-3, -7, -8, and -9, and PARP were increased, while Bcl-2 protein levels were reduced by EGCG treatment. Taken together, EGCG induces B lymphoma cell apoptosis by triggering caspase-dependent intrinsic (mitochondrial) and extrinsic (death receptor) pathways. These findings suggest that EGCG may be a potential agent for the treatment of B lymphoma.

Show MeSH
Related in: MedlinePlus