Browsing by Author "Kuo, Wei-Wen"

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Apicidin-resistant HA22T hepatocellular carcinoma cells massively promote pro-survival capability via IGF-IR/PI3K/Akt signaling pathway activation
(2014-01-01)
Hsu, Hsi-Hsien
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Cheng, Li-Hao
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Ho, Tsung-Jung
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Kuo, Wei-Wen
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Lin, Yueh-Min
Despite rapid advances in the diagnostic and surgical procedures, hepatocellular carcinoma (HCC) remains one of the most difficult human malignancies to treat. This may be due to the chemoresistant behaviors of HCC. It is believed that acquired resistance could be overcome and improve the overall survival of HCC patients by understanding the mechanisms of chemoresistance in HCC. A stable HA22T cancer line, which is chronically resistant to a histone deacetylase inhibitor, was established. After comparing the molecular mechanism of apicidin-R HA22T cells to parental ones by Western blotting, cell cycle-regulated proteins did not change in apicidin-R cells, but apicidin-R cells were more proliferative and had higher tumor growth (wound-healing assay and nude mice xenograft model). Moreover, apicidin-R cells displayed increased levels of p-IGF-IR, p-PI3K, p-Akt, Bcl-xL, and Bcl-2 but also significantly inhibited the tumor suppressor PTEN protein and apoptotic pathways when compared to the parental strain. Therefore, the highly proliferative effect of apicidin-R HA22T cells was blocked by Akt knockdown. For all these findings, we believe that novel strategies to attenuate IGF-IR/PI3K/Akt signaling could overcome chemoresistance toward the improvement of overall survival of HCC patients.
Dung-Shen Downregulates the Synergistic Apoptotic Effects of Angiotensin II Plus Leu 27-IGF II on Cardiomyoblasts
(2014-01-01)
Chang, Ko-Shih
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Lee, Nien-Hung
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Kuo, Wei-Wen
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Hu, Wei-Syun
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Chang, Mu-Hsin
Background: Insulin growth factor II (IGFII) is expressed after ischemic stress in pig hearts and after myocardial infarction in humans. However, its receptor (IGFIIR) cannot be found in normal adult hearts. Moreover, a mouse IGFII overexpression model showed a heart and kidney hypertrophy phenomenon similar to Beckwith-Wiedemann syndrome in humans. The previous studies from our lab showed that an increase in AngII in H9c2 cells causes an elevation in IGFII and IGFIIR through MEK and JNK activation, leading to a rise in intracellular Ca2+ ions, activation of calcineurin by PLC-beta 3 via Gaq, insertion into mitochondrial membranes of BAD, and apoptosis via activation of caspases 9 and 3. Codonopsis pilosula (Dung-shen) has various uses in traditional Chinese medicine, including lowering blood pressure, and increasing red and white blood cell counts. Methods: The purpose of our study is to investigate whether the addition of C. pilosula will attenuate the Angl I plus Leu27-IGF11-induced apoptosis in H9c2 cardiomyoblast cells. Results: From MTT [3-(4, 5-dimethy1-2-thiazolyI)-2, 5-dipheny1-2-tetrazolium bromide] results, it was revealed that Angll plus Leu27-IGFII significantly reduced cell viability, which was reversed by C. pilosula. Additionally, C. pilosula also reversed apoptosis (TUNEL staining) increased by Angll plus Leu27-IGFII. Up-regulation of caspase 3 by Angl I plus Leu27-IGFII was attenuated by C. pilosula treatment, as shown in western blotting assay and immunofluorescence microscopy results. Conclusions: C. pilosula is able to suppress the apoptotic pathway enhanced by Angl I plus Leu27-IGFII in myocardial cells.
Exploring the molecular mechanisms of OSU-03012 on vascular smooth muscle cell proliferation
(2010-11-01)
Kuo, Wei-Wen
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Weng, Jing-Ru
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Huang, Chih-Yang
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Tsai, Chang-Hai
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Liu, Wei-Hung
Restenosis is resulted from the proliferation and migration of vascular smooth muscle cells (VSMCs) from the arterial media into the intima within the vessel lumen following percutaneous transluminal coronary angioplasty (PTCA). OSU-03012, a synthetic compound (2-amino-N-{4-[5-(2-phenanthrenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]-phenyl} acetamide) acting as a PDK-1 inhibitor, is used as an apoptosis-promoting anticancer drug. However, whether OSU-03012 can inhibit VSMC proliferation and migration following PTCA remains unclear. In this study, we used A10 smooth muscle cells cultured in 10% FBS for stimulating proliferation and evaluated the inhibitory effects of OSU-03012 on cell proliferation and migration. The data demonstrated that OSU-03012 dose-dependently inhibited A10 cell proliferation examined by Trypan blue, MTT and morphological alteration assays, and inhibited the levels of proliferation-related proteins, proliferating cell nuclear antigen (PCNA), phosphorylated ERK examined by western blotting. Additionally, 10 mu M OSU-03012 also enhanced apoptosis examined using DAPI assay by regulating apoptosis-related proteins. Furthermore, compared with the control group, A10 cells treated with 10 mu M OSU-03012 showed a lower number of migrating cells examined by Boyden Chamber assay, and a dose-dependently reduced NFkB-dependent and interferon-stimulated response element (ISRE) promoter luciferase activities, implying the anti-migration and anti-inflammation effects of OSU03012. Taken together, this study provides insights into the pharmacological mechanisms of OSU-03012 in preventing smooth muscle cell proliferation, migration, and inflammation supporting the novel discovery of OSU-03012 as an adjuvant therapy for balloon injury-induced restenosis.
NADPH oxidase-derived superoxide Anion-induced apoptosis is mediated via the JNK-dependent activation of NF-kappa B in cardiomyocytes exposed to high glucose
(2012-04-01)
Tsai, Kun-Hsi
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Wang, Wei-Jan
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Lin, Cheng-Wen
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Pai, Peiying
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Lai, Tung-Yuan
Hyperglycemia-induced generation of reactive oxygen species (ROS) can lead to cardiomyocyte apoptosis and cardiac dysfunction. However, the mechanism by which high glucose causes cardiomyocyte apoptosis is not clear. In this study, we investigated the signaling pathways involved in NADPH oxidase-derived ROS-induced apoptosis in cardiomyocytes under hyperglycemic conditions. H9c2 cells were treated with 5.5 or 33 mM glucose for 36?h. We found that 33 mM glucose resulted in a time-dependent increase in ROS generation as well as a time-dependent increase in protein expression of p22phox, p47phox, gp91phox, phosphorylated I?B, c-Jun N-terminal kinase (JNK) and p38, as well as the nuclear translocation of NF-kB. Treatment with apocynin or diphenylene iodonium (DPI), NADPH oxidase inhibitors, resulted in reduced expression of p22phox, p47phox, gp91phox, phosphorylated I?B, c-Jun N-terminal kinase (JNK) and p38. In addition, treatment with JNK and NF-kB siRNAs blocked the activity of caspase-3. Furthermore, treatment with JNK, but not p38, siRNA inhibited the glucose-induced activation of NF-?B. Similar results were obtained in neonatal cardiomyocytes exposed to high glucose concentrations. Therefore, we propose that NADPH oxidase-derived ROS-induced apoptosis is mediated via the JNK-dependent activation of NF-B in cardiomyocytes exposed to high glucose. J. Cell. Physiol. 227: 1347-1357, 2012. (C) 2011 Wiley Periodicals, Inc.