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Quercetin enhances apoptotic effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in ovarian cancer cells through reactive oxygen species (ROS) mediated CCAAT enhancer-binding protein homologous protein (CHOP)-death receptor 5 pathway.

Yi L, Zongyuan Y, Cheng G, Lingyun Z, Guilian Y, Wei G - Cancer Sci. (2014)

Bottom Line: Upregulation of DR5 was mediated through the generation of reactive oxygen species (ROS), as ROS scavengers reduced the effect of quercetin on JNK activation, CHOP upregulation, DR induction, TRAIL sensitization, downregulated the expression of cell survival proteins and upregulated the proapoptotic proteins.Furthermore, quercetin enhances TRAIL mediated inhibition of tumor growth of human SKOV-3 xenograft was associated with induction of apoptosis, activation of caspase-3, CHOP and DR5.Overall, our data suggest that quercetin enhances apoptotic death of ovarian cancer cells to TRAIL through upregulation of CHOP-induced DR5 expression following ROS mediated endoplasmic reticulum-stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

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CCAAT enhancer-binding protein homologous protein (CHOP) plays a crucial role in enhancing apoptotic effect of quercetin in SKOV-3 cells treated with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). (a) Knockdown of CHOP with siRNA represses DR5 expression in SKOV-3 cells. Scrambled siRNA and CHOP siRNA were transfected into the cells followed by quercetin treatment for 24 h. Total cell lysates were subjected to Western blot analysis with specific antibodies to CHOP and DR5. (b) Western blotting analysis for the detection of caspase-3 and 9 activation and PARP cleavage. Cells treated with siRNA as in (a) were further challenged with quercetin (200 μM) and TRAIL (25 ng/mL) for 24 h and were lysed to be subjected to Western blot with the respective antibodies. (c) Flow cytometric analysis. Cells treated as in (b) were stained for the determination of annexin V/PI positive populations using flow cytometry. *P < 0.05 when compared to control.
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fig05: CCAAT enhancer-binding protein homologous protein (CHOP) plays a crucial role in enhancing apoptotic effect of quercetin in SKOV-3 cells treated with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). (a) Knockdown of CHOP with siRNA represses DR5 expression in SKOV-3 cells. Scrambled siRNA and CHOP siRNA were transfected into the cells followed by quercetin treatment for 24 h. Total cell lysates were subjected to Western blot analysis with specific antibodies to CHOP and DR5. (b) Western blotting analysis for the detection of caspase-3 and 9 activation and PARP cleavage. Cells treated with siRNA as in (a) were further challenged with quercetin (200 μM) and TRAIL (25 ng/mL) for 24 h and were lysed to be subjected to Western blot with the respective antibodies. (c) Flow cytometric analysis. Cells treated as in (b) were stained for the determination of annexin V/PI positive populations using flow cytometry. *P < 0.05 when compared to control.

Mentions: CHOP, a resident chaperone in the ER, is a key regulator of DR5.10,23 To determine in more detail how quercetin modulates the expression of DR5, SKOV-3 cells were treated with quercetin for 24 h and qPCR analysis was performed for the determination of CHOP expression. Quercetin significantly increased CHOP expression in a dose-dependent manner (Fig.4b). To further confirm that CHOP regulates DR5 expression, SKOV-3 cells were transfected with CHOP siRNA, followed by quercetin. Knockdown of CHOP in SKOV-3 cells diminished quercetin induced increased production of DR5 (Fig.5a). Moreover, CHOP knockdown greatly reduced caspase-3 and 9 activation as well as PARP cleavage in cells treated with both quercetin and TRAIL (Fig.5b). Fluorescence-activated cell sorting analyses showed also that cell apoptosis was restored upon the depletion of CHOP by siRNA treatment (Fig.5c). These findings suggest that CHOP upregulates DR5 expression, which could be one of the mechanisms by which quercetin enhances TRAIL induced apoptosis in ovarian cancer cells.


Quercetin enhances apoptotic effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in ovarian cancer cells through reactive oxygen species (ROS) mediated CCAAT enhancer-binding protein homologous protein (CHOP)-death receptor 5 pathway.

Yi L, Zongyuan Y, Cheng G, Lingyun Z, Guilian Y, Wei G - Cancer Sci. (2014)

CCAAT enhancer-binding protein homologous protein (CHOP) plays a crucial role in enhancing apoptotic effect of quercetin in SKOV-3 cells treated with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). (a) Knockdown of CHOP with siRNA represses DR5 expression in SKOV-3 cells. Scrambled siRNA and CHOP siRNA were transfected into the cells followed by quercetin treatment for 24 h. Total cell lysates were subjected to Western blot analysis with specific antibodies to CHOP and DR5. (b) Western blotting analysis for the detection of caspase-3 and 9 activation and PARP cleavage. Cells treated with siRNA as in (a) were further challenged with quercetin (200 μM) and TRAIL (25 ng/mL) for 24 h and were lysed to be subjected to Western blot with the respective antibodies. (c) Flow cytometric analysis. Cells treated as in (b) were stained for the determination of annexin V/PI positive populations using flow cytometry. *P < 0.05 when compared to control.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4317845&req=5

fig05: CCAAT enhancer-binding protein homologous protein (CHOP) plays a crucial role in enhancing apoptotic effect of quercetin in SKOV-3 cells treated with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). (a) Knockdown of CHOP with siRNA represses DR5 expression in SKOV-3 cells. Scrambled siRNA and CHOP siRNA were transfected into the cells followed by quercetin treatment for 24 h. Total cell lysates were subjected to Western blot analysis with specific antibodies to CHOP and DR5. (b) Western blotting analysis for the detection of caspase-3 and 9 activation and PARP cleavage. Cells treated with siRNA as in (a) were further challenged with quercetin (200 μM) and TRAIL (25 ng/mL) for 24 h and were lysed to be subjected to Western blot with the respective antibodies. (c) Flow cytometric analysis. Cells treated as in (b) were stained for the determination of annexin V/PI positive populations using flow cytometry. *P < 0.05 when compared to control.
Mentions: CHOP, a resident chaperone in the ER, is a key regulator of DR5.10,23 To determine in more detail how quercetin modulates the expression of DR5, SKOV-3 cells were treated with quercetin for 24 h and qPCR analysis was performed for the determination of CHOP expression. Quercetin significantly increased CHOP expression in a dose-dependent manner (Fig.4b). To further confirm that CHOP regulates DR5 expression, SKOV-3 cells were transfected with CHOP siRNA, followed by quercetin. Knockdown of CHOP in SKOV-3 cells diminished quercetin induced increased production of DR5 (Fig.5a). Moreover, CHOP knockdown greatly reduced caspase-3 and 9 activation as well as PARP cleavage in cells treated with both quercetin and TRAIL (Fig.5b). Fluorescence-activated cell sorting analyses showed also that cell apoptosis was restored upon the depletion of CHOP by siRNA treatment (Fig.5c). These findings suggest that CHOP upregulates DR5 expression, which could be one of the mechanisms by which quercetin enhances TRAIL induced apoptosis in ovarian cancer cells.

Bottom Line: Upregulation of DR5 was mediated through the generation of reactive oxygen species (ROS), as ROS scavengers reduced the effect of quercetin on JNK activation, CHOP upregulation, DR induction, TRAIL sensitization, downregulated the expression of cell survival proteins and upregulated the proapoptotic proteins.Furthermore, quercetin enhances TRAIL mediated inhibition of tumor growth of human SKOV-3 xenograft was associated with induction of apoptosis, activation of caspase-3, CHOP and DR5.Overall, our data suggest that quercetin enhances apoptotic death of ovarian cancer cells to TRAIL through upregulation of CHOP-induced DR5 expression following ROS mediated endoplasmic reticulum-stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

Show MeSH
Related in: MedlinePlus