Biomedical subjects

Ching-Sheng Yeh

Publications and source records attributed to Ching-Sheng Yeh.

7 recordsLinked to original sources

PubMed2006

Fatty acid metabolism pathway play an important role in carcinogenesis of human colorectal cancers by Microarray-Bioinformatics analysis.

The present study systematically explored metabolic pathways and altered expressions of genes speculatively participating in colorectal carcinogenesis by using a Microarray-Bioinformatic analysis methods. The results revealed that 157 genes were up-regulated and 281 genes were down-regulated in colorectal cancer (CRC). Gene Ontology (GO) and relevant bioinformatics tools indicated that the functional category to which 438 genes (12%; 438/3800) of the most frequent alteration belonged was metabolism. The analysis of 10 colorectal cancer tissue specimens demonstrated that genes involved in fatty acid metabolic pathways had high rates of overexpression. In addition, we stimulated CRL-1790 cell line with linoleic acid (a polyunsaturated fatty acid) for 12, 24, 48 and 72 h. Cell proliferation was elevated by 5, 25, 28 and 31% (P<0.05), respectively. Further analyses revealed that the genes increasingly expressed in the cell line included enoyl-Coenzyme A, hydratase/3-hydroxyacyl Coenzyme A dehydrogenase (EHHADH), enoyl Coenzyme A hydratase, short chain, 1, mitochondrial (ECHS1); glutaryl-Coenzyme A dehydrogenase (GCDH), acyl-Coenzyme A oxidase 2, branched chain (ACOX2); acyl-Coenzyme A dehydrogenase, C-2 to C-3 short chain precursor (ACADS); carnitine palmitoyltransferase 1B (CPT1B), acyl-CoA synthetase long-chain family member 5 (ACSL5), and cytochrome P450, family 4, subfamily A, and polypeptide 11 (CYP4A11) genes. This indicated that the stimulating effect of linoleic acid on cell proliferation was due to interference with the metabolic pathway of fatty acid metabolism. In conclusion, genes with altered expression levels in CRC were mainly associated with fatty acid metabolic pathways speculated to have an important role linked to carcinogenesis.

Aged↗

PubMed2006

Sarco/endoplasmic reticulum calcium-ATPase 2 expression as a tumor marker in colorectal cancer.

Maintaining a high calcium concentration in the endoplasmic reticulum through the action of sarco/endoplasmic reticulum calcium-ATPases (SERCAs) is crucial in many cell functions involved in intracellular signal transduction, control of proliferation, programmed cell death, or the synthesis of mature proteins. Recent studies have found that many SERCAs have altered expression patterns in various malignancies. The purpose of the current study was to quantify the expression of SERCA2 in colorectal cancer (CRC) tissues and the corresponding noncancerous tissues, and to statistically analyze whether the SERCA2 expression levels correlate with the clinico-pathologic features and prognosis of CRC patients. Paired colorectal tissue samples from cancerous and the corresponding noncancerous tissues were obtained from 50 patients who underwent surgical resection. Semiquantitative measurements of SERCA2 messenger RNA (mRNA) expression were done using the multiplex reverse transcriptase-polymerase chain reaction. CRC tissues were analyzed through immunohistochemistry for the SERCA2 protein. SERCA2 mRNA overexpression in cancerous tissues compared with normal counterparts was observed in 45 of 50 (90%) patients. The mean expression level of SERCA2 mRNA in cancerous tissues was significantly higher than that in noncancerous tissues (P = 0.01). Increased SERCA2 protein expression was significantly correlated with serosal invasion (P = 0.012), lymph node metastasis (P = 0.009), and advanced tumor stage (P = 0.004). Furthermore, patients with high SERCA2 expression had a significantly poorer overall survival rate than patients with low SERCA2 (P = 0.032). Multivariate analyses indicated that tumor stage (P = 0.015) and SERCA2 expression were independently correlated with overall survival (P = 0.018). The result of this study indicated that SERCA2 may be a molecular determinant in the development and progression of CRC. The molecular mechanisms underlying the SERCA-dependent calcium accumulation and CRC tumorigenesis are worthy of further investigations.

Adenocarcinoma↗

PubMed2006

Molecular detection of circulating cancer cells in the peripheral blood of patients with colorectal cancer by using membrane array with a multiple mRNA marker panel.

The objective of this study was mainly to evaluate the simultaneous detection of expression levels of a multiple mRNA marker panel in the peripheral blood of colorectal cancer (CRC) patients for use in complementary CRC diagnosis. Twenty-seven tumor tissue specimens and 80 peripheral blood specimens were collected from CRC patients. Firstly, the levels of multiple molecular markers in the tumor tissue and blood specimens were evaluated by using real-time quantitative PCR (RT-QPCR) and membrane array. The result of linear regression showed a high degree of correlation (r=0.954, P<0.0001) between the data of these two methods. CK-19 was the marker with the highest detection rate (87.5%) in the peripheral blood, followed by CEA (82.6%), REG4 (80.8%), and then uPA (80.0%) and TLAM1 (80.0%). The levels of the six markers in the peripheral blood were extensively explored. In the 80 patients, the frequency of CK-19, CK-20, CEA, REG4, uPA, and TIAM1 mRNA overexpression was 82.5% (66/80), 78.8% (63/80), 82.5% (66/80), 80.0% (64/80), 78.8% (63/80), and 80.0% (64/80), respectively. Then, a panel combining these 6 mRNA markers was evaluated for its utility in the clinical diagnosis of CRC. The sensitivity, specificity, and accuracy of membrane array-based diagnostic method were 88.8%, 87.8%, and 88.2%, respectively; much higher than those of examinations with single markers. Finally, lymph node metastasis (P=0.024) and TNM stage (P=0.009) were found to be significantly correlated with overexpression of the multiple mRNA marker panel. The detection rates of stage-I and -II CRC by using the multi-marker membrane array were 54.5% (6/11) and 92.0% (23/25), respectively. In conclusion, the results of the present study have shown that this innovative membrane array technique with a multiple mRNA marker panel can significantly improve the diagnosis rate of early colorectal cancer.

Adult↗

PubMed2006

Development and evaluation of a colorimetric membrane-array method for the detection of circulating tumor cells in the peripheral blood of Taiwanese patients with colorectal cancer.

Early detection is the hallmark of successful cancer treatment. Evidence is accumulating that primary cancers begin shedding neoplastic cells in the circulation at an early stage. To date, a high-sensitivity and high-throughput method for the detection of circulating tumor cells (CTCs) is deficient. In this study, we have developed a high-sensitivity colorimetric membrane-array method to detect CTCs in the peripheral blood of colorectal cancer (CRC) patients as a potential diagnostic tool. Previously, we identified a set of 18 oligonucleotide clones, significantly overexpressed in CRC, which were synthesized and applied to a nylon membrane. Digoxigenin (DIG)-labeled cDNA were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) from the peripheral blood of 88 Taiwanese CRC patients and 50 healthy subjects, and were then hybridized to the membrane-array. Hybridization signals were detected by color development. Meanwhile, blood samples were analyzed by real-time quantitative PCR (Q-PCR). Subsequently, both methods were compared regarding their correlation, sensitivity and specificity in the detection of CTCs by statistics. The results of membrane-arrays were demonstrated to be closely related to that of Q-PCR (P<0.001). The sensitivity and specificity of membrane-arrays for the detection of CTCs were 94.3% (95% CI, 86.4-102.2%) and 94% (95% CI, 85.9-102.1%), respectively. Moreover, the accuracy of membrane-arrays is higher than that of any one gene by Q-PCR. The detection rate of membrane-arrays was significantly associated with the depth of tumor invasion (P=0.002), the presence of lymph node metastasis (P=0.016), and TNM stage (P=0.005). The preliminary results indicated that the accuracy of membrane-arrays was sufficient to distinguish Taiwanese CRC patients from normal individuals with the advantages of time-saving, cost-effectiveness and high-throughput. Thus, the constructed colorimetric membrane-array could be a promising approach for the future detection of CTCs.

Adult↗

PubMed2005

Analysis of progressively overexpressed genes in tumorigenesis of colorectal cancers using cDNA microarray.

The identification of differentially expressed genes has important implications in understanding the biology of colorectal tumorigenesis and progression, as well as developing new diagnostic and therapeutic strategies. In this study, cDNA microarray technology was used to identify colorectal tumor-related functional genes, which are overexpressed continuously from colorectal adenoma to adenocarcinoma. A set of 23 genes with progressive overexpression in the development of colorectal cancer (CRC) was identified by cDNA microarray, then analyzed by sequencing and Northern blot analysis. Validation of our array results was simultaneously performed by exploring the SAGEmap database. Furthermore, the gradually over-expressed genes from adenoma to adenocarcinoma were validated by Northern blot analysis with additional samples from three patients with synchronous colorectal adenocarcinoma and adenoma and four patients with CRC. Of these 23 genes, one was a function-unknown gene, designated as Homo sapiens chromosome 21q22.1 anonymous mRNA sequence (Genbank accession no. AF003738), and 22 were function-known genes. Searching through the Gene Ontology Browser at the Cancer Genome Analysis Project website revealed that the biological roles of these 22 function-known genes are involved in cell motility, cell adhesion, chemokine activity, signal transduction, cytoskeleton organization, proteolysis, apoptosis, and cell proliferation. The genes identified in the present study offer valuable information on colorectal carcinogenesis and metastasis, and represent a potential source of novel targets for new strategies for CRC diagnosis and therapy.

Blotting, Northern↗

PubMed2003

High frequency of activated K-ras codon 15 mutant in colorectal carcinomas from Taiwanese patients.

Colorectal carcinogenesis is regarded as a multistep process resulting from accumulation of genetic alterations, including activation of protooncogenes and inactivation of tumor suppressor genes via signal transduction trigger the stage-wise progression to malignancy. The reported incidence of K-ras mutation detected in general tissue samples ranges from 21-60% in primary colorectal cancers (CRC). To assess the prevalence and spectrum of K-ras mutations in Taiwanese patients with CRC, we analyzed 65 CRC patients by polymerase chain reaction-single strand conformation polymorphism analysis, followed by direct sequencing. K-ras mutations were detected in 43.1% (28 of 65) of the tumors. The mutational hot spots were located at codons 12, 13, 15 and 20, especially with the highest frequency at codon 15. To understand whether the codon 15 mutations in CRC were associated with activation of K-ras oncogene and the alterations of its biocharacteristics, mutant K-ras genes were cloned from tumor tissues and then inserted into expression vector pBKCMV to construct the prokaryotic expression plasmid pK15MCMV. Mutant K-ras genes were expressed at high levels in E. coli and the mutant K-ras proteins were shown to be functional with respect to their well-known specific, high-affinity, GDP/GTP binding. The purified K-ras protein from E. coli was then measured for its intrinsic GTPase activity and the extrinsic GTPase activity in the presence of GTPase-activating protein for ras. We found that the extrinsic GTPase activity of the codon 15 mutant K-ras proteins (p21(K-ras15M)) in the presence of GAP is much lower than that of the wild-type K-ras protein (p21 BN), whereas the intrinsic GTPase activity is nearly the same as that of the wild-type K-ras protein. The results indicated that mutation at the codon 15 of K-ras gene indeed decreased GTPase activity in CRC, however, its association with tumorigenesis of CRC needs be clarified by further studies.

Adult↗

PubMedDate not supplied

Directional shape complementarity at the protein-DNA interface.

Nature utilizes various styles of architecture for DNA-binding proteins to recognize diverse DNA sequences, a process facilitated by a complementary surface between protein and DNA. However, the extent and ways this 'shape complementarity' occurs at the protein-DNA interface have yet to be characterized. Here, by analyzing a set of diverse protein-DNA complexes of known three-dimensional structures, we investigated whether the normal vectors of a protein surface at the interface exhibited any relationship with DNA conformation. Generally, the normal vectors of a DNA-contacting protein surface distinctly preferred certain angles, enabling them to align with certain axes characterizing the conformation of DNA. Thus, a new geometric property of DNA-binding protein is demonstrated, i.e. the "shape complementarity" of protein-DNA recognition clearly bears the property of "directionality".

DNA↗