Browsing by Author "Wang, Chao-Ching"

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A Scalable High-Performance Virus Detection Processor Against a Large Pattern Set for Embedded Network Security
(2012-05-01)
Cheng, Chieh-Jen
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Wang, Chao-Ching
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Ku, Wei-Chun
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Chen, Tien-Fu
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Wang, Jinn-Shyan
Contemporary network security applications generally require the ability to perform powerful pattern matching to protect against attacks such as viruses and spam. Traditional hardware solutions are intended for firewall routers. However, the solutions in the literature for firewalls are not scalable, and they do not address the difficulty of an antivirus with an ever-larger pattern set. The goal of this work is to provide a systematic virus detection hardware solution for network security for embedded systems. Instead of placing entire matching patterns on a chip, our solution is a two-phase dictionary-based antivirus processor that works by condensing as much of the important filtering information as possible onto a chip and infrequently accessing off-chip data to make the matching mechanism scalable to large pattern sets. In the first stage, the filtering engine can filter out more than 93.1% of data as safe, using a merged shift table. Only 6.9% or less of potentially unsafe data must be precisely checked in the second stage by the exact-matching engine from off-chip memory. To reduce the impact of the memory gap, we also propose three enhancement algorithms to improve performance: 1) a skipping algorithm; 2) a cache method; and 3) a prefetching mechanism.
Blockade of ITGA2 Induces Apoptosis and Inhibits Cell Migration in Gastric Cancer
(2018-05-01)
Chuang, Yu-Chang
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Wu, Hsin-Yi
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Lin, Yu-Ling
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Tzou, Shey-Cherng
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Chuang, Cheng-Hsun
Background: Gastric cancer is currently the fourth leading cause of cancer-related death worldwide. Gastric cancer is often diagnosed at advanced stages and the outcome of the treatment is often poor. Therefore, identifying new therapeutic targets for this cancer is urgently needed. Integrin alpha 2 (ITGA2) subunit and the beta 1 subunit form a heterodimer for a transmembrane receptor for extracellular matrix, is an important molecule involved in tumor cell proliferation, survival and migration. Integrin alpha 2 beta 1 is over-expressed on a variety of cancer cells, but is low or absent in most normal organs and resting endothelial cells. Results: In this report, we assessed the ITGA2 as the potential therapeutic target with the bioinformatics tools from the TCGA dataset in which composed of 375 gastric cancer tissues and 32 gastric normal tissues. According to the information from the Cancer Cell Line Encyclopedia (CCLE) database, the AGS cell line with ITGA2 high expression and the SUN-1 cell line with low expression were chosen for the further investigation. Interestingly, the anti-ITGA2 antibody (at 3 mu g/ml) inhibited approximately 50% survival of the AGS cells (over-expressed ITGA2), but had no effect in SNU-1 cells (ITGA2 negative). The extents of antibody-mediated cancer inhibition positively correlated with the expression levels of the ITGA2. We further showed that the anti-ITGA2 antibody induced apoptosis by upregulating the RhoA-p38 MAPK signaling to promote the expressions of Bim, Apaf-1 and Caspase-9, whereas the expressions of Ras and Bax/Bcl-2 were not affected. Moreover, blocking ITGA2 by the specific antibody at lower doses also inhibited cell migration of gastric cancer cells. Blockade of ITGA2 by a specific antibody down-regulated the expression of N-WASP, PAK and LIMK to impede actin organization and cell migration of gastric cancer cells. Conclusions: Here, we showed that the mRNA expression levels of ITGA2 comparing to normal tissues significantly increased. In addition, the results revealed that targeting integrin alpha 2 subunit by antibodies did not only inhibit cell migration, but also induce apoptosis effect on gastric cancer cells. Interestingly, higher expression level of ITGA2 led to significant effects on apoptosis progression during anti-ITGA2 antibody treatment, which indicated that ITGA2 expression levels directly correlate with their functionality. Our findings suggest that ITGA2 is a potential therapeutic target for gastric cancer.
Development of an inflammatory tissue-selective chimeric TNF receptor
(2019-01-01)
Lee, Chia-Jung
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Wang, Chao-Ching
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Chen, Michael
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Chuang, Kuo-Hsiang
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Cheng, Tian-Lu
Background: Inhibiting TNF-alpha is an effective therapy for inflammatory diseases such as rheumatoid arthritis. However, systemic, nondiscriminatory neutralization of TNF-alpha is associated with considerable adverse effects. Methods: Here, we developed a trimeric chimeric TNF receptor by linking an N-terminal mouse Acrp30 trimerization domain and an MMP-2/9 substrate sequence to the mouse extracellular domain of TNF receptor 2 followed by a C-terminal mouse tetranectin coiled-coil domain (mouse Acrp-MMP-TNFR-Tn). Results: Here, we show that the Acrp30 trimerization domain inhibited the binding activity of TNFR, possibly by closing the binding site of the trimeric receptor. Cleavage of the substrate sequence by MMP-9, an enzyme highly expressed in inflammatory sites, restored the binding activity of the mouse TNF receptor. We also constructed a recombinant human chimeric TNF receptor (human Acrp-MMP-TNFR-Tn) in which an MMP-13 substrate sequence was used to link the human Acrp and the human TNF receptor 2. Human Acrp-MMP-TNFR-Tn showed reduced binding activity, and MMP-13 digestion recovered its binding activity with TNF-alpha. Conclusion: Acrp-masked chimeric TNF receptors may be able to be used for inflammatory tissue-selective neutralization of TNF-alpha to reduce the adverse effects associated with systemic neutralization of TNF-alpha.