Ya-Ling Hsu

Isoobtusilactone A Induces Cell Cycle Arrest and Apoptosis through Reactive Oxygen Species/Apoptosis Signal-Regulating Kinase 1 Signaling Pathway in Human Breast Cancer Cells

This study is the first to investigate the anticancer effect of isoobtusilactone A (IOA) in two human breast cancer cell lines, MCF-7 and MDA-MB-231. IOA exhibited effective cell growth inhibition by inducing cancer cells to undergo G(2)-M phase arrest and apoptosis. Further investigation revealed that IOAs inhibition of cell growth was also evident in a nude mice model. Cell cycle blockade was associated with increased levels of p21 and reduced amounts of cyclin B1, cyclin A, cdc2, and cdc25C. IOA also enhanced the levels of inactivated phosphorylated cdc2 and cdc25C. IOA triggered the mitochondrial apoptotic pathway, as indicated by a change in Bax/Bcl-2 ratios, resulting in mitochondrial membrane potential loss, cytochrome c release, and caspase-9 activation. We also found that the generation of reactive oxygen species (ROS) is a critical mediator in IOA-induced cell growth inhibition. Enhancement of ROS by IOA activated apoptosis signal-regulating kinase 1 (ASK1) resulted in the increased activation of c-Jun NH(2)-terminal kinase and p38. Antioxidants EUK8 and N-acetyl cystenine significantly decreased apoptosis by inhibiting the ASK1 dephosphorylation at Ser(967) and subsequently increased the interaction of ASK1 with thioredoxin or 14-3-3 proteins. Moreover, blocking ASK1 by small interfering RNA inhibition completely suppressed IOA-induced apoptosis. Taken together, these results imply a critical role for ROS and ASK1 in IOAs anticancer activity.

6-Shogaol, an active constituent of dietary ginger, induces autophagy by inhibiting the AKT/mTOR pathway in human non-small cell lung cancer A549 cells.

This study is the first study to investigate the anticancer effect of 6-shogaol in human non-small cell lung cancer A549 cells. 6-Shogaol inhibited cell proliferation by inducing autophagic cell death, but not, predominantly, apoptosis. Pretreatment of cells with 3-methyladenine (3-MA), an autophagy inhibitor, suppressed 6-shogaol mediated antiproliferation activity, suggesting that induction of autophagy by 6-shogaol is conducive to cell death. We also found that 6-shogaol inhibited survival signaling through the AKT/mTOR signaling pathway by blocking the activation of AKT and downstream targets, including the mammalian target of rapamycin (mTOR), forkhead transcription factors (FKHR) and glycogen synthase kinase-3beta (GSK-3beta). Phosphorylation of both of mTORs downstream targets, p70 ribosomal protein S6 kinase (p70S6 kinase) and 4E-BP1, was also diminished. Overexpression of AKT by AKT cDNA transfection decreased 6-shogaol mediated autophagic cell death, supporting inhibition of AKT beneficial to autophagy. Moreover, reduction of AKT expression by siRNA potentiated 6-shogaols effect, also supporting inhibition of AKT beneficial to autophagy. Taken together, these findings suggest that 6-shogaol may be a promising chemopreventive agent against human non-small cell lung cancer.

Arctigenin, a dietary phytoestrogen, induces apoptosis of estrogen receptor-negative breast cancer cells through the ROS/p38 MAPK pathway and epigenetic regulation

This study investigates the anticancer effect of arctigenin (ATG), a natural lignan product of Arctium lappa L., in human breast cancer MDA-MB-231 cells. Results indicate that ATG inhibits MDA-MB-231 cell growth by inducing apoptosis in vitro and in vivo. ATG triggers the mitochondrial caspase-independent pathways, as indicated by changes in Bax/Bcl-2 ratio, resulting in AIF and EndoG nuclear translocation. ATG increased cellular reactive oxygen species (ROS) production by increasing p22(phox)/NADPH oxidase 1 interaction and decreasing glutathione level. ATG clearly increases the activation of p38 MAPK, but not JNK and ERK1/2. Antioxidant EUK-8, a synthetic catalytic superoxide and hydrogen peroxide scavenger, significantly decreases ATG-mediated p38 activation and apoptosis. Blocking p38 with a specific inhibitor suppresses ATG-mediated Bcl-2 downregulation and apoptosis. Moreover, ATG activates ATF-2, a transcription factor activated by p38, and then upregulates histone H3K9 trimethylation in the Bcl-2 gene promoter region, resulting in Bcl-2 downregulation. Taken together, the results demonstrate that ATG induces apoptosis of MDA-MB-231 cells via the ROS/p38 MAPK pathway and epigenetic regulation of Bcl-2 by upregulation of histone H3K9 trimethylation.

MicroRNA-33a functions as a bone metastasis suppressor in lung cancer by targeting parathyroid hormone related protein

BACKGROUND Bone is a common site of metastasis for lung cancer, and is associated with significant morbidity and a dismal prognosis. MicroRNAs (miRNAs) are increasingly implicated in regulating the progression of malignancies. METHODS The efficacy of miR-33a or anti-miR-33a plasmid was assessed by Real-time PCR. Luciferase assays were using One-Glo Luciferase Assay System. Measurement of secreted factors was determined by ELISA kit. RESULTS We have found that miR-33a, which is downregulated in lung cancer cells, directly targets PTHrP (parathyroid hormone-related protein), a potent stimulator of osteoclastic bone resorption, leading to decreased osteolytic bone metastasis. We also found that miR-33a levels are inversely correlated with PTHrP expression between human normal bronchial cell line and lung cancer cell lines. The reintroduction of miR-33a reduces the stimulatory effect of A549 on the production of osteoclastogenesis activator RANKL (receptor activator of nuclear factor kappa-B ligand) and M-CSF (macrophage colony-stimulating factor) on osteoblasts, while the expression of PTHrP is decreased in A549 cells. miR-33a overexpression also reduces the inhibitory activity of A549 on the production of OPG (osteoprotegerin), an osteoclastogenesis inhibitor. In addition, miR-33a-mediated PTHrP downregulation results in decreased IL-8 secretion in A549, which contributes to decreased lung cancer-mediated osteoclast differentiation and bone resorption. CONCLUSIONS These findings have led us to conclude that miR-33a may be a potent tumor suppressor, which inhibits direct and indirect osteoclastogenesis through repression of PTHrP. GENERAL SIGNIFICANCE miR-33a may even predict a poor prognosis for lung cancer patients.

miRNA-199a-5p regulates VEGFA in endometrial mesenchymal stem cells and contributes to the pathogenesis of endometriosis.

It is believed that endometrial miRNAs contribute to the aetiology of endometriosis in stem cells; however, the mechanisms remain unclear. Here we collected serum samples from patients with or without endometriosis and characterized the miRNA expression profiles of these two groups. MicroRNA‐199a‐5p (miR‐199a‐5p) was dramatically down‐regulated in patients with endometriosis compared with control patients. In addition, we found that the tumour suppressor gene, SMAD4, could elevate miR‐199a‐5p expression in ectopic endometrial mesenchymal stem cells. Up‐regulation of miR‐199a‐5p suppressed cell proliferation, motility and angiogenesis of these ectopic stem cells by targeting the 3′ untranslated region of VEGFA. Furthermore, we established an animal model of endometriosis and found that miR‐199a‐5p could decrease the size of endometriotic lesions in vivo. Taken together, this newly identified miR‐199a‐5p module provides a new avenue to the understanding of the processes of endometriosis development, especially proliferation, motility and angiogenesis, and may facilitate the development of potential therapeutics against endometriosis. Copyright

Glabridin, an isoflavan from licorice root, inhibits migration, invasion and angiogenesis of MDA-MB-231 human breast adenocarcinoma cells by inhibiting focal adhesion kinase/Rho signaling pathway

SCOPE In this study we first report the antimigration, antiinvasive effect of glabridin, a flavonoid obtained from licorice, in MDA-MB-231 human breast adenocarcinoma cells. METHODS AND RESULTS Glabridin exhibited effective inhibition of cell metastasis by decreasing cancer cell migration and invasion of MDA-MB-231 cells. In addition, glabridin also blocked human umbilical vein endothelial cells (HUVEC) migration and decreased MDA-MB-231-mediated angiogenesis. Further investigation revealed that the inhibition of cancer angiogenesis by glabridin was also evident in a nude mice model. Blockade of MDA-MB-231 cells and HUVEC migration was associated with an increase of αγβ3 integrin proteosome degradation. Glabridin also decreased the active forms of FAK and Src, and enhanced levels of inactivated phosphorylated Src (Tyr 416), decreasing the interaction of FAK and Src. Inhibition of the FAK/Src complex by glabridin also blocked AKT and ERK1/2 activation, resulting in reduced activation of RhoA as well as myosin light chain phosphorylation. CONCLUSION This study demonstrates that glabridin may be a novel anticancer agent for the treatment of breast cancer in three different ways: inhibition of migration, invasion and angiogenesis.

6-Dehydrogingerdione, an active constituent of dietary ginger, induces cell cycle arrest and apoptosis through reactive oxygen species/c-Jun N-terminal kinase pathways in human breast cancer cells.

This study is the first to investigate the anticancer effect of 6-dehydrogingerdione (DGE), an active constituent of dietary ginger, in human breast cancer MDA-MB-231 and MCF-7 cells. DGE exhibited effective cell growth inhibition by inducing cancer cells to undergo G2/M phase arrest and apoptosis. Blockade of cell cycle was associated with increased levels of p21, and reduced amounts of cyclin B1, cyclin A, Cdc2 and Cdc25C. DGE also enhanced the levels of inactivated phosphorylated Cdc2 and Cdc25C. DGE triggered the mitochondrial apoptotic pathway indicated by a change in Bax/Bcl-2 ratios, resulting in caspase-9 activation. We also found the generation of reactive oxygen species is a critical mediator in DGE-induced cell growth inhibition. DGE clearly increased the activation of apoptosis signal-regulating kinase 1 and c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase 1/2 (ERK1/2) and p38. In addition, antioxidants vitamin C and catalase significantly decreased DGE-mediated JNK activation and apoptosis. Moreover, blocking JNK by specific inhibitors suppressed DGE-triggered mitochondrial apoptotic pathway. Taken together, these findings suggest that a critical role for reactive oxygen species and JNK in DGE-mediated apoptosis of human breast cancer.

Erratum to “Subamolide A Induces Mitotic Catastrophe Accompanied by Apoptosis in Human Lung Cancer Cells”

There are some errors that occurred during uploading Figures 5(a), 6(b), 6(e), and 7(b). The following are the corrected figures.

Glabridin Inhibits Migration, Invasion, and Angiogenesis of Human Non–Small Cell Lung Cancer A549 Cells by Inhibiting the FAK/Rho Signaling Pathway

This study reports the antimigration, anti-invasive effect of glabridin, a flavonoid obtained from licorice, in human non–small cell lung cancer A549 cells. Glabridin exhibited effective inhibition of cell metastasis by decreasing cancer cell migration and invasion of A549 cells. In addition, glabridin also decreased A549-mediated angiogenesis. Further investigation revealed that glabridin’s inhibition of cancer angiogenesis was also evident in a nude mice model. Blockade of A549 cells migration was associated with an increase of ανβ3 integrin proteosome degradation. Glabridin also decreased the active forms of FAK and Src, and enhanced levels of inactivated phosphorylated Src (Tyr 527), decreasing the interaction of FAK and Src. Inhibition of the FAK/Src complex by glabridin also blocked Akt activation, resulting in reduced activation of RhoA and myosin light chain phosphorylation. This study demonstrates that glabridin may be a novel anticancer agent for the treatment of lung cancer in 3 different ways: inhibition of migration, invasion, and angiogenesis.

4-Shogaol, an Active Constituent of Dietary Ginger, Inhibits Metastasis of MDA-MB-231 Human Breast Adenocarcinoma Cells by Decreasing the Repression of NF-κB/Snail on RKIP

4-Shogaol is one of the phytoconstituents isolated from dried red ginger, which is commercially available to consumers. Some active constituents from ginger have been found to have anti-inflammatory and antioxidant effects, but studies on 4-shogaol have been relatively rare. This is the first report describing the antimetastasis activities of 4-shogaol and the possible mechanisms. This study determined that 4-shogaol inhibits the migration and invasion of MDA-MB-231 and causes mesenchymal-epithelial transition (MET). In addition, 4-shogaol suppresses the activation of NF-κB and cell migration and invasion induced by TNF-α. Furthermore, 4-shogaol has been shown to inhibit the phosphorylation of IκB and the translocation of NF-κB/Snail in MDA-MB-231. This study shows that RKIP, an inhibitory molecule of IKK, is up-regulated after 4-shogaol treatment and prolongs the inhibitory effects of 4-shogaol. Inhibition of RKIP by shRNA transfection significantly decreases the inhibitory effect of 4-shogaol on the NF-κB/Snail pathway, together with cell migration and invasion, whereas overexpression of Snail suppresses 4-shogaol-mediated metastasis inhibition and E-cadherin upregulation. Finally, the animal model revealed that 4-shogaol effectively inhibits metastasis of MDA-MB-231 in mice. This study demonstrates that 4-shogaol may be a novel anticancer agent for the the treatment of metastasis in breast cancer.