Browsing by Author "Liu, Huei-Fang"

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7-Chloro-6-piperidin-1-yl-quinoline-5,8-dione (PT-262), a novel ROCK inhibitor blocks cytoskeleton function and cell migration
(2011-04-01)
Tsai, Chih-Chien
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Liu, Huei-Fang
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Hsu, Kai-Cheng
;
Yang, Jinn-Moon
;
Chen, Chinpiao
The 5,8-quinolinediones are precursors for producing multiple types of bioactive products. In this study, we investigated a new compound derived from 5,8-quinolinediones, 7-chloro-6-piperidin-1-yl-quinoline-5,8-dione (designated as PT-262), which markedly induced cytoskeleton remodeling and migration inhibition in lung carcinoma cells. Comparison with various cytoskeleton inhibitors, including paclitaxel, colchicine and phallacidin, the cell morphology following treatment with PT-262 was similar to phallacidin on the cell elongation and abnormal actin polymerization. However, PT-262 did not directly bind to actin filaments. ROCK (Rho-associated coiled-coil forming protein kinase) is a downstream effector of RhoA to mediate the phosphorylation of myosin light chain (MLC) and cytoskeleton reorganization. The RhoA-ROCK-MLC pathway has been shown to promote cancer cell migration and metastasis. Interestingly. PT-262 was more effective on inhibiting ROCK kinase activities than specific ROCK inhibitors Y-27632 and H-1152. PT-262 induced cytoskeleton remodeling and migration inhibition in A549 lung carcinoma cells. The total MLC and phosphorylated MLC proteins and stress fibers were blocked after treatment with PT-262. Nonetheless, the RhoA protein and GTPase activity were not altered by PT-262. A computational model suggests that PT-262 interacts with the ATP-binding site of ROCK protein. Together, these findings demonstrate that PT-262 is a new ROCK inhibitor. (C) 2011 Elsevier Inc. All rights reserved.
Celecoxib induces p53-PUMA pathway for apoptosis in human colorectal cancer cells
(2008-10-22)
Liu, Huei-Fang
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Hsiao, Po-Wen
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Chao, Jui-I
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生物科技學系
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Department of Biological Science and Technology
Celecoxib, a clinical non-steroidal anti-inflammatory drug, displays anticarcinogenic and chemopreventive activities in human colorectal cancers, although the mechanisms of apoptosis by celecoxib are poorly understood. The existence of functional p53 but not securin in colorectal cancer cells was higher on the induction of cytotoxicity than the p53-mutational colorectal cancer cells following celecoxib treatment. The p53-wild type HCT116 cells were more susceptible to increase similar to 25% cell death than the p53-null HCT116 cells after treatment with 100 mu M celecoxib for 24 h.Transfection with a small interfering RNA of p53 reduced the celecoxib-induced cytotoxicity in the RKO (p53-wild type) colorectal cancer cells. Celecoxib (80-100 mu M for 24 h) significantly increased total p53 proteins and the phosphorylated p53 proteins at serine-15,-20,-46, and -392 in RKO cells. However, the phospho-p53 (serine-15, 20, and -392) proteins were presented on the nuclei of cells but the phospho-p53 (serine-46) protein was located on the cytoplasma of apoptotic cells following treatment with celecoxib. Interestingly, the p53 up-regulated modulator of apoptosis (PUMA) protein, which located on the mitochondria, was induced by celecoxib in the p53-functional colorectal cancer cells but not in the p53-mutational cells. Together, this study provides the first time that celecoxib induces the various phosphorylated sites of p53 and activates p53-PUMA pathway, which potentiates the apoptosis induction in human colorectal cancer cells. Crown Copyright (c) 2008 Published by Elsevier Ireland Ltd. All rights reserved.
Evidence of securin-mediated resistance to gefitinib-induced apoptosis in human cancer cells
(2013-04-25)
Yu, Sheng-Yi
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Liu, Huei-Fang
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Wang, Su-Pei
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Chang, Chia-Ching
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Tsai, Chuan-Mei
Gefitinib, a tyrosine kinase inhibitor of the epidermal growth factor receptor (EGFR), has been used to treat numerous cancers; however, evidence has shown that cancer cells can become resistant to gefitinib during therapy. Here, we report a human proto-oncogene, securin, which displays resistance to death in cancer cells. Gefitinib treatment decreases securin levels at the protein level by inducing protein instability but did not affect on the securin gene expression. Treatment with gefitinib induced cytotoxicity in various human cancer cell types, including RKO (colon cancer), A549 (lung cancer), BFTC905 (bladder cancer), MCF7 (breast cancer) and A375 (skin cancer). BFTC905 and A549 cells expressed relatively high levels of the phosphorylated and total EGFR proteins; however, A375, MCF7 and RKO cells did not markedly express these proteins. Moreover, following treatment with gefitinib, the securin-wild type cancer cells were more resistant to apoptotic induction than the securin-null cancer cells. Surprisingly, both the securin-wild type and securin-null cancer cells expressed the EGFR protein at similar levels. Treatment with gefitinib induced mitochondrial dysfunction, cytochrome c release, caspase-3 activation and poly (ADP-ribose) polymerase protein cleavage, indicating that apoptosis occurred in these cancer cells. The transfection of a GPF-securin expression vector increased both the proliferation rates and resistance to gefitinib-induced death in these cancer cells. Taken together, these findings demonstrate that the presence of securin promotes resistance to gefitinib-induced apoptosis via an EGFR-independent pathway in human cancer cells. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
MicroRNA-30a inhibits cell migration and invasion by downregulating vimentin expression and is a potential prognostic marker in breast cancer
(2012-08-01)
Cheng, Chun-Wen
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Wang, Hsiao-Wei
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Chang, Chia-Wei
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Chu, Hou-Wei
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Chen, Cheng-You
"Tumor recurrence and metastasis result in an unfavorable prognosis for cancer patients. Recent studies have suggested that specific microRNAs (miRNAs) may play important roles in the development of cancer cells. However, prognostic markers and the outcome prediction of the miRNA signature in breast cancer patients have not been comprehensively assessed. The aim of this study was to identify miRNA biomarkers relating to clinicopathological features and outcome of breast cancer. A miRNA microarray analysis was performed on breast tumors of different lymph node metastasis status and with different progression signatures, indicated by overexpression of cyclin D1 and beta-catenin genes, to identify miRNAs showing a significant difference in expression. The functional interaction between the candidate miRNA, miR-30a, and the target gene, Vim, which codes for vimentin, a protein involved in epithelial-mesenchymal transition, was examined using the luciferase reporter assay, western blotting, and migration and invasion assays. The association between the decreased miR-30a levels and breast cancer progression was examined in a survival analysis. miR-30a negatively regulated vimentin expression by binding to the 3'-untranslated region of Vim. Overexpression of miR-30a suppressed the migration and invasiveness phenotypes of breast cancer cell lines. Moreover, reduced tumor expression of miR-30a in breast cancer patients was associated with an unfavorable outcome, including late tumor stage, lymph node metastasis, and worse progression (mortality and recurrence) (p < 0.05). In conclusion, these findings suggest a role for miR-30a in inhibiting breast tumor invasiveness and metastasis. The finding that miR-30a downmodulates vimentin expression might provide a therapeutic target for the treatment of breast cancer."
Opposite Expression of Securin and gamma-H2AX Regulates Baicalein-Induced Cancer Cell Death
(2010-10-01)
Jiang, Ren-Huei
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Su, Wen-Chi
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Liu, Huei-Fang
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Huang, Hou-Syun
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Chao, Jui-I
Securin and gamma-H2AX have been shown to regulate cell survival and genomic stability. However, it is still unknown how the expression and regulation of these proteins is altered following treatment with baicalein, a natural flavonoid extracted from the Scutellaria baicalensis root. In the present study, we investigate the possible roles of securin and gamma-H2AX in baicalein-induced cancer cell death. Baicalein reduced cell viability in a variety of human cancer cell lines, including bladder, cervical, colon, and lung cancer cells. Interestingly, baicalein treatment (40-80 mu M for 24 h) markedly inhibited securin expression, while the levels of gamma-H2AX were elevated. Abnormal spindle formation and chromosomal segregation were induced by baicalein. Furthermore, wild type HCT116 cancer cells had a higher incidence of cytotoxicity and apoptosis than securin-null HCT116 cells following treatment with baicalein. In contrast, baicalein increased the levels of gamma-H2AX to a similar extent in both cell types. Transfection with H2AX siRNA further increased baicalein-induced cell death. Additionally, blockade of the AKT pathway by treatment with wortmannin or AKT shRNA lowered the levels of gamma-H2AX and enhanced cytotoxicity in baicalein-treated cells. Taken together, our findings suggest that the opposing effects of baicalein on securin and gamma-H2AX levels may be involved in the regulation of cell viability and genomic stability by this compound. J. Cell. Biochem. 111: 274-283, 2010. (C) 2010 Wiley-Liss, Inc.
Oxaliplatin down-regulates survivin by p38 MAP kinase and proteasome in human colon cancer cells
(2010-12-05)
Liu, Huei-Fang
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Hu, Huai-Chin
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Chao, Jui-I
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分子醫學與生物工程研究所
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Institute of Molecular Medicine and Bioengineering
Oxaliplatin, a platinum derivative cancer drug, has been used for treating human colorectal cancers. Survivin has been proposed as a cancer target, which highly expressed in most cancer cells but not normal adult cells. In this study, we investigated the regulation of survivin expression by exposure to oxaliplatin in human colon cancer cells. Oxaliplatin (3-9 mu M for 24 h) markedly induced cytotoxicity, proliferation inhibition and apoptosis in the human RKO colon cancer cells. The survivin protein expression of RKO cells is dramatically reduced by oxaliplatin; however, the survivin gene expression is slightly altered. The survivin blockage of oxaliplatin elevated caspase-3 activation and apoptosis in RKO cells. Over-expression of survivin proteins by transfection with a survivin-expressed vector resisted the oxaliplatin-induced cancer cell death. Meantime, oxaliplatin elicited the phosphorylation of p38 mitogen-activated protein (MAP) kinase. SB202190, a specific p38 MAP kinase inhibitor, restored the survivin protein level and attenuated oxaliplatin-induced cancer cell death. In addition, oxaliplatin increased the levels of phospho-p53 (Ser-15) and total p53 proteins. Inhibition of p53 expression by a specific p53 inhibitor pifithrin-alpha reduced the phosphorylated p38 MAP kinase and active caspase-3 proteins in the oxaliplatin-exposed RKO cells. In contrast, SB202190 did not alter the oxaliplatin-induced p53 protein level. Furthermore, treatment with a specific proteasome inhibitor MG132 restored survivin protein level in the oxaliplatin-treated colon cancer cells. Taken together, our results demonstrate for the first time that survivin is down-regulated by p38 MAP kinase and proteasome degradation pathway after treatment with oxaliplatin in the human colon cancer cells. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
Ubiquitin-coated nanodiamonds bind to autophagy receptors for entry into the selective autophagy pathway
(2017-01-01)
Liu, Kuang-Kai
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Qiu, Wei-Ru
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Raj, Emmanuel Naveen
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Liu, Huei-Fang
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Huang, Hou-Syun
Selective macroautophagy/autophagy plays a pivotal role in the processing of foreign pathogens and cellular components to maintain homeostasis in human cells. To date, numerous studies have demonstrated the uptake of nanoparticles by cells, but their intracellular processing through selective autophagy remains unclear. Here we show that carbon-based nanodiamonds (NDs) coated with ubiquitin (Ub) bind to autophagy receptors (SQSTM1 [sequestosome 1], OPTN [optineurin], and CALCOCO2/NDP52 [calcium binding and coiled-coil domain 2]) and are then linked to MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) for entry into the selective autophagy pathway. NDs are ultimately delivered to lysosomes. Ectopically expressed SQSTM1-green fluorescence protein (GFP) could bind to the Ub-coated NDs. By contrast, the Ub-associated domain mutant of SQSTM1 (UBA)-GFP did not bind to the Ub-coated NDs. Chloroquine, an autophagy inhibitor, prevented the ND-containing autophagosomes from fusing with lysosomes. Furthermore, autophagy receptors OPTN and CALCOCO2/NDP52, involved in the processing of bacteria, were found to be involved in the selective autophagy of NDs. However, ND particles located in the lysosomes of cells did not induce mitotic blockage, senescence, or cell death. Single ND clusters in the lysosomes of cells were observed in the xenografted human lung tumors of nude mice. This study demonstrated for the first time that Ub-coated nanoparticles bind to autophagy receptors for entry into the selective autophagy pathway, facilitating their delivery to lysosomes.
YY Ubiquitin-coated nanodiamonds bind to autophagy receptors for entry into the selective autophagy pathway
(2017)
Liu, Kuang-Kai
;
Qiu, Wei-Ru
;
Raj, Emmanuel Naveen
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Liu, Huei-Fang
;
Huang, Hou-Syun
Selective macroautophagy/autophagy plays a pivotal role in the processing of foreign pathogens and cellular components to maintain homeostasis in human cells. To date, numerous studies have demonstrated the uptake of nanoparticles by cells, but their intracellular processing through selective autophagy remains unclear. Here we show that carbon-based nanodiamonds (NDs) coated with ubiquitin (Ub) bind to autophagy receptors (SQSTM1 [sequestosome 1], OPTN [optineurin], and CALCOCO2/NDP52 [calcium binding and coiled-coil domain 2]) and are then linked to MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) for entry into the selective autophagy pathway. NDs are ultimately delivered to lysosomes. Ectopically expressed SQSTM1-green fluorescence protein (GFP) could bind to the Ub-coated NDs. By contrast, the Ub-associated domain mutant of SQSTM1 (UBA)-GFP did not bind to the Ub-coated NDs. Chloroquine, an autophagy inhibitor, prevented the ND-containing autophagosomes from fusing with lysosomes. Furthermore, autophagy receptors OPTN and CALCOCO2/NDP52, involved in the processing of bacteria, were found to be involved in the selective autophagy of NDs. However, ND particles located in the lysosomes of cells did not induce mitotic blockage, senescence, or cell death. Single ND clusters in the lysosomes of cells were observed in the xenografted human lung tumors of nude mice. This study demonstrated for the first time that Ub-coated nanoparticles bind to autophagy receptors for entry into the selective autophagy pathway, facilitating their delivery to lysosomes.
YY Ubiquitin-coated nanodiamonds bind to autophagy receptors for entry into the selective autophagy pathway
(2017)
Liu, Kuang-Kai
;
Qiu, Wei-Ru
;
Raj, Emmanuel Naveen
;
Liu, Huei-Fang
;
Huang, Hou-Syun
Selective macroautophagy/autophagy plays a pivotal role in the processing of foreign pathogens and cellular components to maintain homeostasis in human cells. To date, numerous studies have demonstrated the uptake of nanoparticles by cells, but their intracellular processing through selective autophagy remains unclear. Here we show that carbon-based nanodiamonds (NDs) coated with ubiquitin (Ub) bind to autophagy receptors (SQSTM1 [sequestosome 1], OPTN [optineurin], and CALCOCO2/NDP52 [calcium binding and coiled-coil domain 2]) and are then linked to MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) for entry into the selective autophagy pathway. NDs are ultimately delivered to lysosomes. Ectopically expressed SQSTM1-green fluorescence protein (GFP) could bind to the Ub-coated NDs. By contrast, the Ub-associated domain mutant of SQSTM1 (UBA)-GFP did not bind to the Ub-coated NDs. Chloroquine, an autophagy inhibitor, prevented the ND-containing autophagosomes from fusing with lysosomes. Furthermore, autophagy receptors OPTN and CALCOCO2/NDP52, involved in the processing of bacteria, were found to be involved in the selective autophagy of NDs. However, ND particles located in the lysosomes of cells did not induce mitotic blockage, senescence, or cell death. Single ND clusters in the lysosomes of cells were observed in the xenografted human lung tumors of nude mice. This study demonstrated for the first time that Ub-coated nanoparticles bind to autophagy receptors for entry into the selective autophagy pathway, facilitating their delivery to lysosomes.