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Role of annexin a5 on mitochondria-dependent apoptosis induced by tetramethoxystilbene in human breast cancer cells.

Hong M, Park N, Chun YJ - Biomol Ther (Seoul) (2014)

Bottom Line: Moreover, we found that the cytosolic release of apoptogenic factors such as cytochrome c, or apoptosis-inducing factor (AIF) in mitochondria was markedly increased.Annexin A5 depletion by siRNA led to decreased proapoptotic factors such as Bax, Bak, and annexin A5.Taken together, our results indicate that annexin A5 may play an important role in TMS-mediated mitochondrial apoptosis through the regulation of proapoptotic proteins and VDAC1 expression.

View Article: PubMed Central - PubMed

Affiliation: College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea.

ABSTRACT
We have previously shown that 2,4,3',5'-tetramethoxystilbene (TMS), a trans-stilbene analogue, induces apoptosis in human cancer cells. However, the detailed mechanisms of mitochondria-dependent apoptosis induced by TMS are not fully understood. In the present study, the possible roles of annexin A5 in TMS-mediated apoptosis were investigated in MCF7 human breast cancer cells. Quantitative real-time PCR analysis and Western blot analysis showed that the expression of annexin A5 was strongly increased in TMS-treated cells. TMS caused a strong translocation of annexin A5 from cytosol into mitochondria. Confocal laser scanning microscopic analysis clearly showed that TMS induced translocation of annexin A5 into mitochondria. TMS increased the expression and oligomerization of voltage-dependent anion channel (VDAC) 1, which may promote mitochondria-dependent apoptosis through disruption of mitochondrial membrane potential. When cells were treated with TMS, the levels of Bax, and Bak as well as annexin A5 were strongly enhanced. Moreover, we found that the cytosolic release of apoptogenic factors such as cytochrome c, or apoptosis-inducing factor (AIF) in mitochondria was markedly increased. Annexin A5 depletion by siRNA led to decreased proapoptotic factors such as Bax, Bak, and annexin A5. Taken together, our results indicate that annexin A5 may play an important role in TMS-mediated mitochondrial apoptosis through the regulation of proapoptotic proteins and VDAC1 expression.

No MeSH data available.


Related in: MedlinePlus

Effect of annexin A5 knockdown on Bax and Bak expression induced by TMS. (A) MCF-7 cells were transfected with annexin A5 siRNA (38 nM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. GAPDH level was determined as loading controls. (B) Cells were transfected with annexin A5 siRNA (38 nM) for 48 h and were then treated with TMS (5 μM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. β-Actin level was determined as loading controls. The data shown are representative of three independent experiments.
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f5-bt-22-519: Effect of annexin A5 knockdown on Bax and Bak expression induced by TMS. (A) MCF-7 cells were transfected with annexin A5 siRNA (38 nM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. GAPDH level was determined as loading controls. (B) Cells were transfected with annexin A5 siRNA (38 nM) for 48 h and were then treated with TMS (5 μM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. β-Actin level was determined as loading controls. The data shown are representative of three independent experiments.

Mentions: To investigate the role of annexin A5 in mitochondria-dependent apoptosis, annexin A5 siRNA was used. As shown in Fig. 5A, treatment with annexin A5 siRNA (40 nM) for 48 h strongly repressed annexin A5 expression. Knockdown of annexin A5 by siRNA also decreased Bax and Bak expression and TMS recovered the inhibition of Bax and Bak expression by annexin A5 siRNA. (Fig. 5B). These results demonstrated that annexin A5 is able to regulate mitochondria-dependent apoptosis through controlling Bax and Bak expression.


Role of annexin a5 on mitochondria-dependent apoptosis induced by tetramethoxystilbene in human breast cancer cells.

Hong M, Park N, Chun YJ - Biomol Ther (Seoul) (2014)

Effect of annexin A5 knockdown on Bax and Bak expression induced by TMS. (A) MCF-7 cells were transfected with annexin A5 siRNA (38 nM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. GAPDH level was determined as loading controls. (B) Cells were transfected with annexin A5 siRNA (38 nM) for 48 h and were then treated with TMS (5 μM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. β-Actin level was determined as loading controls. The data shown are representative of three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256031&req=5

f5-bt-22-519: Effect of annexin A5 knockdown on Bax and Bak expression induced by TMS. (A) MCF-7 cells were transfected with annexin A5 siRNA (38 nM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. GAPDH level was determined as loading controls. (B) Cells were transfected with annexin A5 siRNA (38 nM) for 48 h and were then treated with TMS (5 μM) for 48 h. After incubation, cells were harvested and total cellular lysates were prepared. Extracted proteins were resolved by SDS-PAGE (10%) and Western blot analysis was conducted. β-Actin level was determined as loading controls. The data shown are representative of three independent experiments.
Mentions: To investigate the role of annexin A5 in mitochondria-dependent apoptosis, annexin A5 siRNA was used. As shown in Fig. 5A, treatment with annexin A5 siRNA (40 nM) for 48 h strongly repressed annexin A5 expression. Knockdown of annexin A5 by siRNA also decreased Bax and Bak expression and TMS recovered the inhibition of Bax and Bak expression by annexin A5 siRNA. (Fig. 5B). These results demonstrated that annexin A5 is able to regulate mitochondria-dependent apoptosis through controlling Bax and Bak expression.

Bottom Line: Moreover, we found that the cytosolic release of apoptogenic factors such as cytochrome c, or apoptosis-inducing factor (AIF) in mitochondria was markedly increased.Annexin A5 depletion by siRNA led to decreased proapoptotic factors such as Bax, Bak, and annexin A5.Taken together, our results indicate that annexin A5 may play an important role in TMS-mediated mitochondrial apoptosis through the regulation of proapoptotic proteins and VDAC1 expression.

View Article: PubMed Central - PubMed

Affiliation: College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea.

ABSTRACT
We have previously shown that 2,4,3',5'-tetramethoxystilbene (TMS), a trans-stilbene analogue, induces apoptosis in human cancer cells. However, the detailed mechanisms of mitochondria-dependent apoptosis induced by TMS are not fully understood. In the present study, the possible roles of annexin A5 in TMS-mediated apoptosis were investigated in MCF7 human breast cancer cells. Quantitative real-time PCR analysis and Western blot analysis showed that the expression of annexin A5 was strongly increased in TMS-treated cells. TMS caused a strong translocation of annexin A5 from cytosol into mitochondria. Confocal laser scanning microscopic analysis clearly showed that TMS induced translocation of annexin A5 into mitochondria. TMS increased the expression and oligomerization of voltage-dependent anion channel (VDAC) 1, which may promote mitochondria-dependent apoptosis through disruption of mitochondrial membrane potential. When cells were treated with TMS, the levels of Bax, and Bak as well as annexin A5 were strongly enhanced. Moreover, we found that the cytosolic release of apoptogenic factors such as cytochrome c, or apoptosis-inducing factor (AIF) in mitochondria was markedly increased. Annexin A5 depletion by siRNA led to decreased proapoptotic factors such as Bax, Bak, and annexin A5. Taken together, our results indicate that annexin A5 may play an important role in TMS-mediated mitochondrial apoptosis through the regulation of proapoptotic proteins and VDAC1 expression.

No MeSH data available.


Related in: MedlinePlus