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Pterostilbene exerts antitumor activity via the Notch1 signaling pathway in human lung adenocarcinoma cells.

Yang Y, Yan X, Duan W, Yan J, Yi W, Liang Z, Wang N, Li Y, Chen W, Yu S, Jin Z, Yi D - PLoS ONE (2013)

Bottom Line: PTE treatment resulted in a dose- and time-dependent decrease in the viability of A549 cells.DAPT (a gamma secretase inhibitor) and Notch1 siRNA prevented the induction of NICD and Hes1 activation by PTE treatment and sensitized the cells to PTE treatment.The down-regulation of Notch signaling also prevented the activation of pro-survival pathways (most notably the PI3K/Akt pathway) after PTE treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an City, China.

ABSTRACT
Although pterostilbene (PTE) has been shown to have potent antitumor activities against various cancer types, the molecular mechanisms of these activities remain unclear. In this study, we investigated the antitumor activity of PTE against human lung adenocarcinoma in vitro and in vivo and explored the role of the Notch1 signaling pathway in this process. PTE treatment resulted in a dose- and time-dependent decrease in the viability of A549 cells. Additionally, PTE exhibited strong antitumor activity, as evidenced not only by a reduced mitochondrial membrane potential (MMP) and a decreased intracellular glutathione content but also by increases in the apoptotic index and the level of reactive oxygen species (ROS). Furthermore, PTE treatment induced the activation of the Notch1 Intracellular Domain (NICD) protein and activated Hes1. DAPT (a gamma secretase inhibitor) and Notch1 siRNA prevented the induction of NICD and Hes1 activation by PTE treatment and sensitized the cells to PTE treatment. The down-regulation of Notch signaling also prevented the activation of pro-survival pathways (most notably the PI3K/Akt pathway) after PTE treatment. In summary, lung adenocarcinoma cells may enhance Notch1 activation as a protective mechanism in response to PTE treatment. Combining a gamma secretase inhibitor with PTE treatment may represent a novel approach for treating lung adenocarcinoma by inhibiting the survival pathways of cancer cells.

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The effects of PTE on the viability, morphology and apoptotic index of lung adenocarcinoma cells.(A) Cells were treated with PTE at different concentrations (1.5, 3 and 6 µM) for different durations (12, 24 and 36 h). Cell viability was assessed using the MTT assay and was expressed as an OD value. (B) The cell morphology was observed under an inverted/phase contrast microscope (treated for 24 h), and images were taken (×200). Significant cell shrinkage and a decreased cellular attachment rate were observed in the PTE-treated group. (C) Apoptosis of the cells was detected by the TUNEL assay (×200), and the level of cell apoptosis was expressed as the apoptotic index. TUNEL staining was performed to stain the nuclei of apoptotic cells (green), and DAPI was used to stain the nuclei of all cells (blue). The apoptotic index was expressed as the number of green cells/the total number of cells counted×100%. The results are expressed as the mean ± SEM, n = 6. **P<0.01 compared with the control group, ##P<0.01 compared with the PTE 1.5 µM group, $$P<0.01 compared with the PTE 3 µM group. PTE, pterostilbene; OD, optical density.
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pone-0062652-g001: The effects of PTE on the viability, morphology and apoptotic index of lung adenocarcinoma cells.(A) Cells were treated with PTE at different concentrations (1.5, 3 and 6 µM) for different durations (12, 24 and 36 h). Cell viability was assessed using the MTT assay and was expressed as an OD value. (B) The cell morphology was observed under an inverted/phase contrast microscope (treated for 24 h), and images were taken (×200). Significant cell shrinkage and a decreased cellular attachment rate were observed in the PTE-treated group. (C) Apoptosis of the cells was detected by the TUNEL assay (×200), and the level of cell apoptosis was expressed as the apoptotic index. TUNEL staining was performed to stain the nuclei of apoptotic cells (green), and DAPI was used to stain the nuclei of all cells (blue). The apoptotic index was expressed as the number of green cells/the total number of cells counted×100%. The results are expressed as the mean ± SEM, n = 6. **P<0.01 compared with the control group, ##P<0.01 compared with the PTE 1.5 µM group, $$P<0.01 compared with the PTE 3 µM group. PTE, pterostilbene; OD, optical density.

Mentions: The viability of A549 cells treated with PTE was determined using an MTT assay, and the data are presented in Figure 1A. The treatment of A549 cells for 12, 24 or 36 h with 1.5, 3 or 6 µM of PTE resulted in cell growth inhibition in a dose- and time-dependent manner. The IC50 (50% inhibitory concentration) of PTE at 24 h was approximately 3.476 µM. The microscopy images (Figure 1B) showed that PTE treatment resulted in significant cell shrinkage and a decrease in the rate of cellular attachment compared with the control treatment. After treatment with 1.5, 3 or 6 µM of PTE for 24 h, the apoptotic index was increased in a dose-dependent manner (P<0.01, compared with the control group). These results provide convincing data showing that PTE can induce apoptosis of A549 cells (Figure 1C).


Pterostilbene exerts antitumor activity via the Notch1 signaling pathway in human lung adenocarcinoma cells.

Yang Y, Yan X, Duan W, Yan J, Yi W, Liang Z, Wang N, Li Y, Chen W, Yu S, Jin Z, Yi D - PLoS ONE (2013)

The effects of PTE on the viability, morphology and apoptotic index of lung adenocarcinoma cells.(A) Cells were treated with PTE at different concentrations (1.5, 3 and 6 µM) for different durations (12, 24 and 36 h). Cell viability was assessed using the MTT assay and was expressed as an OD value. (B) The cell morphology was observed under an inverted/phase contrast microscope (treated for 24 h), and images were taken (×200). Significant cell shrinkage and a decreased cellular attachment rate were observed in the PTE-treated group. (C) Apoptosis of the cells was detected by the TUNEL assay (×200), and the level of cell apoptosis was expressed as the apoptotic index. TUNEL staining was performed to stain the nuclei of apoptotic cells (green), and DAPI was used to stain the nuclei of all cells (blue). The apoptotic index was expressed as the number of green cells/the total number of cells counted×100%. The results are expressed as the mean ± SEM, n = 6. **P<0.01 compared with the control group, ##P<0.01 compared with the PTE 1.5 µM group, $$P<0.01 compared with the PTE 3 µM group. PTE, pterostilbene; OD, optical density.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643961&req=5

pone-0062652-g001: The effects of PTE on the viability, morphology and apoptotic index of lung adenocarcinoma cells.(A) Cells were treated with PTE at different concentrations (1.5, 3 and 6 µM) for different durations (12, 24 and 36 h). Cell viability was assessed using the MTT assay and was expressed as an OD value. (B) The cell morphology was observed under an inverted/phase contrast microscope (treated for 24 h), and images were taken (×200). Significant cell shrinkage and a decreased cellular attachment rate were observed in the PTE-treated group. (C) Apoptosis of the cells was detected by the TUNEL assay (×200), and the level of cell apoptosis was expressed as the apoptotic index. TUNEL staining was performed to stain the nuclei of apoptotic cells (green), and DAPI was used to stain the nuclei of all cells (blue). The apoptotic index was expressed as the number of green cells/the total number of cells counted×100%. The results are expressed as the mean ± SEM, n = 6. **P<0.01 compared with the control group, ##P<0.01 compared with the PTE 1.5 µM group, $$P<0.01 compared with the PTE 3 µM group. PTE, pterostilbene; OD, optical density.
Mentions: The viability of A549 cells treated with PTE was determined using an MTT assay, and the data are presented in Figure 1A. The treatment of A549 cells for 12, 24 or 36 h with 1.5, 3 or 6 µM of PTE resulted in cell growth inhibition in a dose- and time-dependent manner. The IC50 (50% inhibitory concentration) of PTE at 24 h was approximately 3.476 µM. The microscopy images (Figure 1B) showed that PTE treatment resulted in significant cell shrinkage and a decrease in the rate of cellular attachment compared with the control treatment. After treatment with 1.5, 3 or 6 µM of PTE for 24 h, the apoptotic index was increased in a dose-dependent manner (P<0.01, compared with the control group). These results provide convincing data showing that PTE can induce apoptosis of A549 cells (Figure 1C).

Bottom Line: PTE treatment resulted in a dose- and time-dependent decrease in the viability of A549 cells.DAPT (a gamma secretase inhibitor) and Notch1 siRNA prevented the induction of NICD and Hes1 activation by PTE treatment and sensitized the cells to PTE treatment.The down-regulation of Notch signaling also prevented the activation of pro-survival pathways (most notably the PI3K/Akt pathway) after PTE treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiovascular Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an City, China.

ABSTRACT
Although pterostilbene (PTE) has been shown to have potent antitumor activities against various cancer types, the molecular mechanisms of these activities remain unclear. In this study, we investigated the antitumor activity of PTE against human lung adenocarcinoma in vitro and in vivo and explored the role of the Notch1 signaling pathway in this process. PTE treatment resulted in a dose- and time-dependent decrease in the viability of A549 cells. Additionally, PTE exhibited strong antitumor activity, as evidenced not only by a reduced mitochondrial membrane potential (MMP) and a decreased intracellular glutathione content but also by increases in the apoptotic index and the level of reactive oxygen species (ROS). Furthermore, PTE treatment induced the activation of the Notch1 Intracellular Domain (NICD) protein and activated Hes1. DAPT (a gamma secretase inhibitor) and Notch1 siRNA prevented the induction of NICD and Hes1 activation by PTE treatment and sensitized the cells to PTE treatment. The down-regulation of Notch signaling also prevented the activation of pro-survival pathways (most notably the PI3K/Akt pathway) after PTE treatment. In summary, lung adenocarcinoma cells may enhance Notch1 activation as a protective mechanism in response to PTE treatment. Combining a gamma secretase inhibitor with PTE treatment may represent a novel approach for treating lung adenocarcinoma by inhibiting the survival pathways of cancer cells.

Show MeSH
Related in: MedlinePlus