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A Taiwanese Propolis Derivative Induces Apoptosis through Inducing Endoplasmic Reticular Stress and Activating Transcription Factor-3 in Human Hepatoma Cells.

Suk FM, Lien GS, Huang WJ, Chen CN, Lu SY, Yang YC, Yan MD, Liang YC - Evid Based Complement Alternat Med (2013)

Bottom Line: First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners.Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells.These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.

View Article: PubMed Central - PubMed

Affiliation: Division of Gastroenterology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 116, Taiwan.

ABSTRACT
Activating transcription factor-(ATF-) 3, a stress-inducible transcription factor, is rapidly upregulated under various stress conditions and plays an important role in inducing cancer cell apoptosis. NBM-TP-007-GS-002 (GS-002) is a Taiwanese propolin G (PPG) derivative. In this study, we examined the antitumor effects of GS-002 in human hepatoma Hep3B and HepG2 cells in vitro. First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners. Several main apoptotic indicators were found in GS-002-treated cells, such as the cleaved forms of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP). GS-002 also induced endoplasmic reticular (ER) stress as evidenced by increases in ER stress-responsive proteins including glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153), phosphorylated eukaryotic initiation factor 2 α (eIF2 α ), phosphorylated protein endoplasmic-reticular-resident kinase (PERK), and ATF-3. The induction of ATF-3 expression was mediated by mitogen-activated protein kinase (MAPK) signaling pathways in GS-002-treated cells. Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells. These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.

No MeSH data available.


Related in: MedlinePlus

The propolis derivative, GS-002, induced ATF-3 expression in human hepatoma cells. (a) Hep3B cells were treated with various concentrations of GS-002 or PPG for 12 h (right panels), or with 10 μg/mL GS-002 or 5 μg/mL PPG for the indicated time periods (left panels), and total RNA was used to detect ATF-3 mRNA levels by an RT-PCR. (b) Hep3B cells were treated with various concentrations of GS-002 for 12 h (right panels) or with 10 μg/mL GS-002 for the indicated time periods (left panels), and total cell lysates were used to detect ATF-3 protein levels by Western blotting. (c) Hep3B cells were transfected with 0.35 μg of the ATF-Luc-1850 reporter plasmid and 0.15 μg phRL-TK for 24 h and then treated with various concentrations of GS-002 for another 24 h. Total cell lysates were used to detect the luciferase activity as described in Section 2.
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fig5: The propolis derivative, GS-002, induced ATF-3 expression in human hepatoma cells. (a) Hep3B cells were treated with various concentrations of GS-002 or PPG for 12 h (right panels), or with 10 μg/mL GS-002 or 5 μg/mL PPG for the indicated time periods (left panels), and total RNA was used to detect ATF-3 mRNA levels by an RT-PCR. (b) Hep3B cells were treated with various concentrations of GS-002 for 12 h (right panels) or with 10 μg/mL GS-002 for the indicated time periods (left panels), and total cell lysates were used to detect ATF-3 protein levels by Western blotting. (c) Hep3B cells were transfected with 0.35 μg of the ATF-Luc-1850 reporter plasmid and 0.15 μg phRL-TK for 24 h and then treated with various concentrations of GS-002 for another 24 h. Total cell lysates were used to detect the luciferase activity as described in Section 2.

Mentions: It is known that ATF-3 is also a stress-responsive protein, which can be induced by ER stress [30]. Next, we wanted to understand whether GS-002 can induce ATF-3 expression in human hepatoma cells. Hep3B cells were treated with GS-002, and we found that GS-002 significantly induced ATF-3 messenger (m)RNA expression in dose- and time-dependent manners (Figure 5(a)). ATF-3 protein expression also increased after GS-002 treatment (Figure 5(b)). However, the GS-002 parental compound, PPG, did not induce ATF-3 expression at a concentration of 10 μg/mL (Figure 5(a), bottom). To examine whether GS-002 induced ATF-3 expression at the transcription level, we used the ATF-Luc-1850 reporter plasmid to determine the gene promoter activity of ATF-3. Hep3B cells were transfected with the ATF-Luc-1850 reporter plasmid and phRL-TK (an internal control plasmid) for 24 h and then treated with various concentrations of GS-002 for another 24 h. As for GS-002 exposure, the gene promoter of ATF-3 in Hep3B cells was upregulated in a dose-dependent manner (Figure 5(c)). These results suggest that GS-002 was able to induce ATF-3 expression at the transcription level.


A Taiwanese Propolis Derivative Induces Apoptosis through Inducing Endoplasmic Reticular Stress and Activating Transcription Factor-3 in Human Hepatoma Cells.

Suk FM, Lien GS, Huang WJ, Chen CN, Lu SY, Yang YC, Yan MD, Liang YC - Evid Based Complement Alternat Med (2013)

The propolis derivative, GS-002, induced ATF-3 expression in human hepatoma cells. (a) Hep3B cells were treated with various concentrations of GS-002 or PPG for 12 h (right panels), or with 10 μg/mL GS-002 or 5 μg/mL PPG for the indicated time periods (left panels), and total RNA was used to detect ATF-3 mRNA levels by an RT-PCR. (b) Hep3B cells were treated with various concentrations of GS-002 for 12 h (right panels) or with 10 μg/mL GS-002 for the indicated time periods (left panels), and total cell lysates were used to detect ATF-3 protein levels by Western blotting. (c) Hep3B cells were transfected with 0.35 μg of the ATF-Luc-1850 reporter plasmid and 0.15 μg phRL-TK for 24 h and then treated with various concentrations of GS-002 for another 24 h. Total cell lysates were used to detect the luciferase activity as described in Section 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814109&req=5

fig5: The propolis derivative, GS-002, induced ATF-3 expression in human hepatoma cells. (a) Hep3B cells were treated with various concentrations of GS-002 or PPG for 12 h (right panels), or with 10 μg/mL GS-002 or 5 μg/mL PPG for the indicated time periods (left panels), and total RNA was used to detect ATF-3 mRNA levels by an RT-PCR. (b) Hep3B cells were treated with various concentrations of GS-002 for 12 h (right panels) or with 10 μg/mL GS-002 for the indicated time periods (left panels), and total cell lysates were used to detect ATF-3 protein levels by Western blotting. (c) Hep3B cells were transfected with 0.35 μg of the ATF-Luc-1850 reporter plasmid and 0.15 μg phRL-TK for 24 h and then treated with various concentrations of GS-002 for another 24 h. Total cell lysates were used to detect the luciferase activity as described in Section 2.
Mentions: It is known that ATF-3 is also a stress-responsive protein, which can be induced by ER stress [30]. Next, we wanted to understand whether GS-002 can induce ATF-3 expression in human hepatoma cells. Hep3B cells were treated with GS-002, and we found that GS-002 significantly induced ATF-3 messenger (m)RNA expression in dose- and time-dependent manners (Figure 5(a)). ATF-3 protein expression also increased after GS-002 treatment (Figure 5(b)). However, the GS-002 parental compound, PPG, did not induce ATF-3 expression at a concentration of 10 μg/mL (Figure 5(a), bottom). To examine whether GS-002 induced ATF-3 expression at the transcription level, we used the ATF-Luc-1850 reporter plasmid to determine the gene promoter activity of ATF-3. Hep3B cells were transfected with the ATF-Luc-1850 reporter plasmid and phRL-TK (an internal control plasmid) for 24 h and then treated with various concentrations of GS-002 for another 24 h. As for GS-002 exposure, the gene promoter of ATF-3 in Hep3B cells was upregulated in a dose-dependent manner (Figure 5(c)). These results suggest that GS-002 was able to induce ATF-3 expression at the transcription level.

Bottom Line: First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners.Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells.These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.

View Article: PubMed Central - PubMed

Affiliation: Division of Gastroenterology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 116, Taiwan.

ABSTRACT
Activating transcription factor-(ATF-) 3, a stress-inducible transcription factor, is rapidly upregulated under various stress conditions and plays an important role in inducing cancer cell apoptosis. NBM-TP-007-GS-002 (GS-002) is a Taiwanese propolin G (PPG) derivative. In this study, we examined the antitumor effects of GS-002 in human hepatoma Hep3B and HepG2 cells in vitro. First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners. Several main apoptotic indicators were found in GS-002-treated cells, such as the cleaved forms of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP). GS-002 also induced endoplasmic reticular (ER) stress as evidenced by increases in ER stress-responsive proteins including glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153), phosphorylated eukaryotic initiation factor 2 α (eIF2 α ), phosphorylated protein endoplasmic-reticular-resident kinase (PERK), and ATF-3. The induction of ATF-3 expression was mediated by mitogen-activated protein kinase (MAPK) signaling pathways in GS-002-treated cells. Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells. These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.

No MeSH data available.


Related in: MedlinePlus