PHYTOMEDICINE
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2016
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IF 2.937
Qin Tang,Fangling Ji,Wenhui Sun,Jingyun Wang,Jianli Guo,Lianying Guo,Yachen Li,Yongming Bao
Background 10-Hydroxy camptothecin (HCPT), a naturally occurring alkaloid, is a clinical drug for cancer chemotherapy . Baicalein (BA) is a flavonoid extracted from the root of Scutellaria baicalensis . The synergistic anti-cancer effect of BA and HCPT has not been reported. Purpose To explore whether and how BA enhances the anti-cancer effect of HCPT in BGC823 cells. Methods Cell viability was measured by MTT assay. Apoptosis and cell cycle were analyzed through flow cytometry and western blotting analysis. DNA damage was determined by a comet assay . The activity of topoisomerase I (Topo I) was detected by the plasmid DNA relaxation assay. The synergistic anti-cancer effect of BA and HCPT in vivo was tested by BGC823 xenografted tumor model. Results BA at non-toxic doses prominently enhanced the anti-cancer activities of HCPT in BGC823, MCF7 and SMMC7721 cells. Combination treatment of BA and HCPT induced BGC823 cells apoptosis mainly via intrinsic rather than extrinsic pathways, and preferentially arresting cell cycle in G1 and G2 phases with the aid of p21 . Of note, p53, the upstream regulator of cell apoptosis and cycle, was increased by 5 folds in combination group. It helped to further trigger DNA damage and inhibit Topo I catalytic activity after combination treatment of BA and HCPT. Moreover, the BGC823 xenografted tumor growth rate in nude mice was repressed in a greater degree ( P < 0.01) in the combinational group than the single-drug group. Conclusion HCPT and BA, a new and effective combination therapy, synergistically target Topo I and up-regulate p53 to induce cell apoptosis and cell cycle arrest.
研究领域:
肿瘤学
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药理学
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分子生物学
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细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
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2017
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IF 3.756
Qin Tang,Fangling Ji,Jingyun Wang,Lianying Guo,Yachen Li,Yongming Bao
Quercetin (Qu) is known as a dietary antioxidant with numerous bioactivities, but its function in anti-cancer has not been fully investigated. Here, we show that Qu at low doses (≤ 10 μM) significantly enhances the inhibition of 10-hydroxy camptothecin (HCPT) on the proliferation of MCF7, BGC823 and HepG2 cells. A plasmid DNA relaxation assay indicates that the inhibition of HCPT on the catalytic activity of topoisomerase I (Topo I) is increased by Qu at 10 μM. Compared to the treatment by Qu or HCPT alone, phosphorylation at Ser 139 of γH2A.X in MCF7 cells starts to increase significantly (P < 0.05) at 6 h when treated by the combination of 10 μM Qu and 0.62 μM HCPT. Moreover, the combinational group successively arrests MCF7 cells at G1, S and G2/M phases from 12 h to 48 h via up-regulation of p21 and induces apoptosis at 24 h by triggering intrinsic cell death pathways. In addition, the inhibition effects of the combinational group on the proliferation of MCF7 cells are eliminated by pretreatment with 100 μM Z-VAD-FMK (a caspase inhibitor). Finally, by using nude mice xenografting assay of MCF7 cells, we demonstrate that tumor inhibition rates of combinational group are significantly higher than single-drug group. In summary, the synergic anti-cancer mechanism of Qu and HCPT in MCF7 cells is through the combined inhibitory effects of Qu and HCPT on Topo I, which synergistically induce cell cycle arrest and apoptosis by triggering DNA damage.
研究领域:
肿瘤学
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药理学
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细胞生物学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMEDICINE & PHARMACOTHERAPY
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2016
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IF 2.326
Qin Tang,Fangling Ji,Jianli Guo,Jingyun Wang,Yachen Li,Yongming Bao
Chrysin , one of natural flavonoid compounds, has recently been found to possess anti-inflammatory, antiallergic and anticancer properties. To increase its anticancer effects, 5 chrysin derivates were synthesized on the base of DNA intercalator structure. The inhibiting effects of chrysin and its derivatives on cancer cells Hela, BGC823, MCF-7, HepG2, and normal cells HEK-293, were evaluated by MTT assays . 5-(2′-amino) phenyl-7-cyclohexanemethylchrysin (Ch-1), a unique chrysin derivate, killed all the cancer cells but kept above 60% survival rate in normal cells HEK-293 at 62.5 μM. Treated with chrysin from 250 μM to 500 μM, those cells were still maintained above 60% survival rate. The result of circular dichroism spectra showed that Ch-1 could intercalate DNA while chrysin had no effects on DNA. Interestingly, Hela cells survival rates were 95% and 10%, after treated with 20 μM and 30 μM of Ch-1, respectively. Both intrinsic and extrinsic apoptotic pathway were identified in regulating the cell death caused by Ch-1 in Hela cells. p53, the upstream regulator of apoptotic pathway were extremely significantly up-regulated in Hela cells treated with 25 μM Ch-1. Moreover, the inhibiting effects and apoptotic related proteins responses to Ch-1 on Hela cells were abolished after pre-treated with Pifithrin-α (Pft-α), a p53 inhibitor. So, p53-depedent apoptosis is the crucial factor governing the inhibiting effects of Ch-1 in Hela cells. Amazingly, Ch-1 at non-toxic concentration (2.5–10 μM) enhanced significantly anti-cancer effect of 10-hydroxy camptothecin (HCPT) on Hela, BGC823, and MCF-7 cells.
研究领域:
癌症研究
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药理学
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细胞生物学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）