Browsing by Author "Chen, Ming-Cheng"

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A new method for post Genome-Wide Association Study (GWAS) analysis of colorectal cancer in Taiwan
(2013-04-10)
Wang, Hwei-Ming
;
Chang, Tzu-Hao
;
Lin, Feng-Mao
;
Chao, Te-Hsin
;
Huang, Wei-Chih
Recently, single nucleotide polymorphisms (SNPs) located in specific loci or genes have been identified associated with susceptibility to colorectal cancer (CRC) in Genome-Wide Association Studies (GWAS). However, in different ethnicities and regions, the genetic variations and the environmental factors can widely vary. Therefore, here we propose a post-GWAS analysis method to investigate the CRC susceptibility SNPs in Taiwan by conducting a replication analysis and bioinformatics analysis. One hundred and forty-four significant SNPs from published GWAS results were collected by a literature survey, and two hundred and eighteen CRC samples and 385 normal samples were collected for post-GWAS analysis. Finally, twenty-six significant SNPs were identified and reported as associated with susceptibility to colorectal cancer, other cancers, obesity, and celiac disease in a previous GWAS study. Functional analysis results of 26 SNPs indicate that most biological processes identified are involved in regulating immune responses and apoptosis. In addition, an efficient prediction model was constructed by applying Jackknife feature selection and ANOVA testing. As compared to another risk prediction model of CRC for European Caucasians population, which performs 0.616 of AUC by using 54 SNPs, the proposed model shows good performance in predicting CRC risk within the Taiwanese population, i.e., 0.724 AUC by using 16 SNPs. We believe that the proposed risk prediction model is highly promising for predicting CRC risk within the Taiwanese population. In addition, the functional analysis results could be helpful to explore the potential associated regulatory mechanisms that may be involved in CRC development. (c) 2012 Elsevier B.V. All rights reserved.
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
;
Ho, Tsung-Jung
;
Kuo, Wei-Wen
;
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.
Comparison of 6 Common Noise Filter Methods for Terrestrial Laser Scanner Target
(2012)
Wu, Chien-Ting
;
Chen, Ming-Cheng
;
土木工程學系
;
Department of Civil Engineering
The terrestrial laser scanner (TLS) is a line-of-sight instrument which can directly acquire dense 3D point clouds in a very short time. The registration method is used to act as a control point for a reflective target placed in overlapping areas in neighboring scanning stations. The main purpose for a reflective target is to be an obvious and precise positioning feature for laser scanning point cloud data. This study compares six common noise filtering methods which are used to eliminate measuring noise in the primitive point cloud of reflective target for better positioning accuracy, i.e. Scatter points removal method, Spikes removal method, Least squares plane method, Gaussian smoothing method, Median smoothing method, and the Average smoothing method. The test results found for 30, 60, and 90 meter distances in this study was that six noise filtering methods can actually increase the reflective target positioning accuracy, and the least squares plane method is the best one in either precision or accuracy. Beside the reflective target, the test is carried out with self-made targets for the comparison of positioning accuracy between the reflective target and self-made targets. Regarding accuracy, the reflective target is superior to the object in 30 and 60m, and self-made target is superior to the reflective target in 90m.