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The Topoisomerase 1 Inhibitor Austrobailignan-1 Isolated from Koelreuteria henryi Induces a G2/M-Phase Arrest and Cell Death Independently of p53 in Non-Small Cell Lung Cancer Cells.

Wu CC, Huang KF, Yang TY, Li YL, Wen CL, Hsu SL, Chen TH - PLoS ONE (2015)

Bottom Line: The molecular event of austrobailignan-1-mediated G2/M phase arrest was associated with the increase of p21Waf1/Cip1 and p27Kip1 expression, and decrease of Cdc25C expression.These events were accompanied by the increase of PUMA and Bax, and the decrease of Mcl-1 and Bcl-2.Overall, our results suggest that austrobailignan-1 is a novel DNA damaging agent and displays a topoisomerase I inhibitory activity, causes DNA strand breaks, and consequently induces DNA damage response signaling for cell cycle G2/M arrest and apoptosis in a p53 independent manner.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, ROC; Department of Medical Research, Chung-Shan Medical University Hospital, Taichung, Taiwan, ROC.

ABSTRACT
Koelreuteria henryi Dummer, an endemic plant of Taiwan, has been used as a folk medicine for the treatment of hepatitis, enteritis, cough, pharyngitis, allergy, hypertension, hyperlipidemia, and cancer. Austrobailignan-1, a natural lignan derivative isolated from Koelreuteria henryi Dummer, has anti-oxidative and anti-cancer properties. However, the effects of austrobailignan-1 on human cancer cells have not been studied yet. Here, we showed that austrobailignan-1 inhibited cell growth of human non-small cell lung cancer A549 and H1299 cell lines in both dose- and time-dependent manners, the IC50 value (48 h) of austrobailignan-1 were 41 and 22 nM, respectively. Data from flow cytometric analysis indicated that treatment with austrobailignan-1 for 24 h retarded the cell cycle at the G2/M phase. The molecular event of austrobailignan-1-mediated G2/M phase arrest was associated with the increase of p21Waf1/Cip1 and p27Kip1 expression, and decrease of Cdc25C expression. Moreover, treatment with 100 nM austrobailignan-1 for 48 h resulted in a pronounced release of cytochrome c followed by the activation of caspase-2, -3, and -9, and consequently induced apoptosis. These events were accompanied by the increase of PUMA and Bax, and the decrease of Mcl-1 and Bcl-2. Furthermore, our study also showed that austrobailignan-1 was a topoisomerase 1 inhibitor, as evidenced by a relaxation assay and induction of a DNA damage response signaling pathway, including ATM, and Chk1, Chk2, γH2AX phosphorylated activation. Overall, our results suggest that austrobailignan-1 is a novel DNA damaging agent and displays a topoisomerase I inhibitory activity, causes DNA strand breaks, and consequently induces DNA damage response signaling for cell cycle G2/M arrest and apoptosis in a p53 independent manner.

No MeSH data available.


Related in: MedlinePlus

The structure pf austrobailignan-1 from the leaves of K. henryi Dummer.(A) The image of K. henryi Dummer (adopted from Herbanum, Academic Sinica, http://digiarch.sinica.edu.tw/content/repository/resource_content.jsp?oid=3819630). (B) The structure of austrobailignan-1 was established via 1H- and 13C-NMR. 13C-NMR assignments were based on HETCOR and long-range HECTOR spectral results.
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pone.0132052.g001: The structure pf austrobailignan-1 from the leaves of K. henryi Dummer.(A) The image of K. henryi Dummer (adopted from Herbanum, Academic Sinica, http://digiarch.sinica.edu.tw/content/repository/resource_content.jsp?oid=3819630). (B) The structure of austrobailignan-1 was established via 1H- and 13C-NMR. 13C-NMR assignments were based on HETCOR and long-range HECTOR spectral results.

Mentions: The austrobailignan-1 used in this study was extracted and purified from the leaves of K. henryi (Fig 1A) according to the processes described elsewhere with minor modification [12]. Briefly, the dried leaves (1 kg) of K. henryi were milled and extracted by 95% ethanol three times at room temperature. The ethanol extract was partitioned with H2O-CH2Cl2 (1:1) mixture, and then the CH2Cl2 fraction was collected and dissolved in 90% methanol followed by extraction with hexane. The methanol fraction was harvested and chromatographed on a silica gel column, using hexane, hexane/CHCl3 and CHCl3/methanol as the eluting solvent followed by thin layer chromatography to collect the cytotoxic fractions. These fractions were pooled and then run through a silica gel column, eluted with a gradient of hexane/EtOAc and followed by a reversed-phase C8 Labor column to yield austrobailignan-1 followed by lyophilization as powder with the purity higher than 90% [22]. The powder was then dissolved in DMSO at a stock concentration of 100 μM for experimental applications. The structure of austrobailignan-1 (Fig 1B) was identified by 2D 1H- and 13C-NMR based on HETCOR and long-range HETCOR spectral data, and direct comparison with the previous data of related lignans [23].


The Topoisomerase 1 Inhibitor Austrobailignan-1 Isolated from Koelreuteria henryi Induces a G2/M-Phase Arrest and Cell Death Independently of p53 in Non-Small Cell Lung Cancer Cells.

Wu CC, Huang KF, Yang TY, Li YL, Wen CL, Hsu SL, Chen TH - PLoS ONE (2015)

The structure pf austrobailignan-1 from the leaves of K. henryi Dummer.(A) The image of K. henryi Dummer (adopted from Herbanum, Academic Sinica, http://digiarch.sinica.edu.tw/content/repository/resource_content.jsp?oid=3819630). (B) The structure of austrobailignan-1 was established via 1H- and 13C-NMR. 13C-NMR assignments were based on HETCOR and long-range HECTOR spectral results.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492957&req=5

pone.0132052.g001: The structure pf austrobailignan-1 from the leaves of K. henryi Dummer.(A) The image of K. henryi Dummer (adopted from Herbanum, Academic Sinica, http://digiarch.sinica.edu.tw/content/repository/resource_content.jsp?oid=3819630). (B) The structure of austrobailignan-1 was established via 1H- and 13C-NMR. 13C-NMR assignments were based on HETCOR and long-range HECTOR spectral results.
Mentions: The austrobailignan-1 used in this study was extracted and purified from the leaves of K. henryi (Fig 1A) according to the processes described elsewhere with minor modification [12]. Briefly, the dried leaves (1 kg) of K. henryi were milled and extracted by 95% ethanol three times at room temperature. The ethanol extract was partitioned with H2O-CH2Cl2 (1:1) mixture, and then the CH2Cl2 fraction was collected and dissolved in 90% methanol followed by extraction with hexane. The methanol fraction was harvested and chromatographed on a silica gel column, using hexane, hexane/CHCl3 and CHCl3/methanol as the eluting solvent followed by thin layer chromatography to collect the cytotoxic fractions. These fractions were pooled and then run through a silica gel column, eluted with a gradient of hexane/EtOAc and followed by a reversed-phase C8 Labor column to yield austrobailignan-1 followed by lyophilization as powder with the purity higher than 90% [22]. The powder was then dissolved in DMSO at a stock concentration of 100 μM for experimental applications. The structure of austrobailignan-1 (Fig 1B) was identified by 2D 1H- and 13C-NMR based on HETCOR and long-range HETCOR spectral data, and direct comparison with the previous data of related lignans [23].

Bottom Line: The molecular event of austrobailignan-1-mediated G2/M phase arrest was associated with the increase of p21Waf1/Cip1 and p27Kip1 expression, and decrease of Cdc25C expression.These events were accompanied by the increase of PUMA and Bax, and the decrease of Mcl-1 and Bcl-2.Overall, our results suggest that austrobailignan-1 is a novel DNA damaging agent and displays a topoisomerase I inhibitory activity, causes DNA strand breaks, and consequently induces DNA damage response signaling for cell cycle G2/M arrest and apoptosis in a p53 independent manner.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, ROC; Department of Medical Research, Chung-Shan Medical University Hospital, Taichung, Taiwan, ROC.

ABSTRACT
Koelreuteria henryi Dummer, an endemic plant of Taiwan, has been used as a folk medicine for the treatment of hepatitis, enteritis, cough, pharyngitis, allergy, hypertension, hyperlipidemia, and cancer. Austrobailignan-1, a natural lignan derivative isolated from Koelreuteria henryi Dummer, has anti-oxidative and anti-cancer properties. However, the effects of austrobailignan-1 on human cancer cells have not been studied yet. Here, we showed that austrobailignan-1 inhibited cell growth of human non-small cell lung cancer A549 and H1299 cell lines in both dose- and time-dependent manners, the IC50 value (48 h) of austrobailignan-1 were 41 and 22 nM, respectively. Data from flow cytometric analysis indicated that treatment with austrobailignan-1 for 24 h retarded the cell cycle at the G2/M phase. The molecular event of austrobailignan-1-mediated G2/M phase arrest was associated with the increase of p21Waf1/Cip1 and p27Kip1 expression, and decrease of Cdc25C expression. Moreover, treatment with 100 nM austrobailignan-1 for 48 h resulted in a pronounced release of cytochrome c followed by the activation of caspase-2, -3, and -9, and consequently induced apoptosis. These events were accompanied by the increase of PUMA and Bax, and the decrease of Mcl-1 and Bcl-2. Furthermore, our study also showed that austrobailignan-1 was a topoisomerase 1 inhibitor, as evidenced by a relaxation assay and induction of a DNA damage response signaling pathway, including ATM, and Chk1, Chk2, γH2AX phosphorylated activation. Overall, our results suggest that austrobailignan-1 is a novel DNA damaging agent and displays a topoisomerase I inhibitory activity, causes DNA strand breaks, and consequently induces DNA damage response signaling for cell cycle G2/M arrest and apoptosis in a p53 independent manner.

No MeSH data available.


Related in: MedlinePlus