Hui-Jen Chang

GLUT1 gene is a potential hypoxic marker in colorectal cancer patients

BackgroundTumor hypoxia is an important factor related to tumor resistance to radiotherapy and chemotherapy. This study investigated molecules synthesized in colorectal cancer cells during hypoxia to explore the possibility of developing molecular probes capable of detecting cell death and/or the efficiency of radiotherapy and chemotherapy.MethodsAt first, we incubated two human colorectal adenocarcinoma cell lines SW480 (UICC stage II) and SW620 (UICC stage III) cells in hypoxic (≤2% O2, 93% N2, and 5% CO2) and normoxic conditions (20% O2, 75% N2, and 5% CO2) for 24 h and 48 h. The relative expression ratio of GLUT1 mRNA in hypoxic conditions was analyzed by RT-PCR. Ten cancerous tissues collected from human colorectal cancer patients were examined. HIF-1α and HIF-2α levels were measured to indicate the degree of hypoxia, and gene expression under hypoxic conditions was determined. As a comparison, HIF-1α, HIF-2α, and GLUT1 levels were measured in the peripheral blood of 100 CRC patients.ResultsHypoxia-induced lactate was found to be elevated 3.24- to 3.36-fold in SW480 cells, and 3.06- to 3.17-fold in SW620 cells. The increased relative expression ratio of GLUT1 mRNA, under hypoxic conditions was higher in SW620 cells (1.39- to 1.72-fold elevation) than in SW480 cells (1.24- to 1.66-fold elevation). HIF-1α and HIF-2α levels were elevated and GLUT1 genes were significantly overexpressed in CRC tissue specimens. The elevated ratio of GLUT1 was higher in stage III and IV CRC tissue specimens than in the stage I and II (2.97–4.73 versus 1.44–2.11). GLUT1 mRNA was also increased in the peripheral blood of stage II and III CRC patients as compared to stage I patients, suggesting that GLUT1 may serve as a hypoxic indicator in CRC patients.ConclusionIn conclusion, this study demonstrated that GLUT1 has the potential to be employed as a molecular marker to indicate the degree of hypoxia experienced by tumors circulating in the blood of cancer patients.

Overexpression of S100B, TM4SF4, and OLFM4 Genes Is Correlated with Liver Metastasis in Taiwanese Colorectal Cancer Patients

Distant metastasis of colorectal cancer (CRC) occurs mainly in the liver and is the major cause of death. This study explored the overexpression of liver metastasis-associated mRNAs in human CRC by using a well-established, weighted enzymatic chip array platform. Analysis of 10 CRC tissue specimens compared with their normal adjacent tissues revealed that ATP2A2, ELAVL4, hTERT, KCTD2, MUC1, OLFM4, S100B, and TM4SF4 genes were upregulated (gene expression ratio of cancer tissue to paired normal tissue was >2) by microarray and bioinformatics analysis. A gene chip including eight candidate genes was constructed to investigate the circulating tumor cells in blood specimens of 103 preoperative CRC patients and further validated by reverse transcriptase-polymerase chain reaction. Liver metastasis was significantly correlated with overexpression of S100B (p=0.001, OR=9.217), TM4SF3 (p=0.011, OR=4.385), and OLFM4 (p=0.015, OR=3.438). These results suggest that S100B, TM4SF3, and OLFM4 overexpression may affect metastatic behavior of tumor cells in Taiwanese CRC patients.

A fast and convenient new technique to detect the therapeutic target, K-ras mutant, from peripheral blood in non-small cell lung cancer patients.

Activating mutation of the K-ras gene was one of the earliest discoveries of genetic alterations in lung cancer. Moreover, K-ras somatic mutations might be suggested for predicting resistance to molecular antibodies targeting the epidermal growth factor receptor (EGFR). However, activated K-ras mutant detection methods are limited to traditional techniques. The techniques are complicated and are used only in tissue samples, which are limited for clinical applications. In a previous study, we established a low-cost, convenient, and easy technique for detecting activated K-ras in a small number of circulating tumor cells by the colorimetric membrane array method (CLMA). However, the sensitivity still needs further improvement. The aim of this study is to develop a new platform with chemiluminescence as reporter and weighted values of target genes on the chip in order to achieve a more sensitive, easier to read, and more accurate platform-weighted chemiluminecent membrane array (WCHMA). In advance, we collected 209 peripheral blood samples of non-small cell lung cancer (NSCLC) from patients to evaluate clinical K-ras activation detection using Activating KRAS Detection Chip both conducted by CLMA and WCHMA. Results show 71 specimens with K-ras mutation, of which 59 were identified as positive through CLMA and 66 were positive through WCHMA. After statistical analysis, the sensitivity of CLMA was found to be 83% and the specificity was 96%. On the other hand, the sensitivity of WCHMA increased to 93% and the specificity remained at 94%. Results of the detection limitation of peripheral blood on two platforms are: 3cancer cells/cm(3) blood using WCHMA, which is better than 5cancer cells/cm(3) blood using CLMA. Further analysis on the correlation between the test results and clinical pathological features shows that the mean score obtained using WCHMA is significantly correlated to TNM stage, tumor size, and metastasis.

CDC25A, VAV1, TP73, BRCA1 and ZAP70 gene overexpression correlates with radiation response in colorectal cancer

Radiotherapy is increasingly used in adjuvant approaches for colorectal cancer (CRC) to reduce local recurrence and improve survival. However, the principal limitation is the large variability in response among different individuals due to tumor heterogeneity. In the present study, we compared gene expression profiles between radiosensitive and radioresistant colorectal cancer cell lines to identify radiation-related molecules that can be used to evaluate the effects of radiation. The CRC cell line SW620 was irradiated with a high-energy photo beam. Following radiation treatment, RNA was extracted from non-irradiated and irradiated cells, respectively, and gene expression analysis was performed by oligonucleotide microarray and the DAVID bioinformatics method. To further confirm the results, an additional 4 CRC cell lines, COLO205, T84, HCT116, SW480 and SW403 were purchased from ATCC. The radiosensitivities of each were determined by the survival fraction at 2 Gray (SF2) of the surviving cells using the ATPLite assay, and the gene expression profiles after irradiation among the radiosensitive and radioresistant cell lines were analyzed by membrane arrays. The relationships between gene expression and patient clinicopathological features were also analyzed using membrane arrays and RT-PCR. The results from oligonucleotide microarray analysis show that 1601 genes were up-regulated (gene expression ratio of post- to pre-radiation treatment>2). By bioinformatic database analysis, 30 up-regulated genes were identified as involved in DNA damage response pathways, immune response pathways and the complement and coagulation cascades pathway. Fifteen genes showed differential gene expression profiles between radiosensitive (HCT116 and SW620) and radioresistant CRC cell lines (SW403 and SW480). In 110 CRC tissues, we detected five genes CDC25A, VAV1, TP73, BRCA1 and ZAP70 from 15 overexpressed genes that significantly related to prognostic factors (tumor size, advanced stage, invasive depth, lymph node metastasis and differentiation). These findings suggest that CDC25A, VAV1, TP73, BRCA1 and ZAP70 may be novel markers for predicting the effectiveness of radiotherapy in CRC patients.

EVI2B, ATP2A2, S100B, TM4SF3, and OLFM4 As Potential Prognostic Markers for Postoperative Taiwanese Colorectal Cancer Patients

Undetected micrometastasis may play a key role in the early relapse of colorectal cancer (CRC) patients. The aim of this study was to detect circulating tumor cells (CTCs) for predicting early relapse of CRC patients by a weighted enzymatic chip array (WEnCA) and analyze 15 candidate genes associated with CRC carcinogenesis. The genes of 105 postoperative CRC patients were analyzed by membrane array and direct sequencing. We constructed a WEnCA platform including five prognosis-related genes and analyzed the detection rate of WEnCA for CTCs in 30 clinically confirmed CRC relapse patients. Postoperative relapse was significantly correlated with gene overexpression, including EVI2B (p=0.001, OR=4.622), ATP2A2 (p=0.006, OR=4.688), S100B (p=0.001, OR=11.521), TM4SF3 (p=0.001, OR=6.756), and OLFM4 (p=0.008, OR=3.545). Using WEnCA (weighting score of each gene: 5 to EVI2B, 5 to ATP2A2, 12 to S100B, 7 to TM4SF3, and 4 to OLFM4), we could detect CTCs presenting these genotypes in relapsed CRC patients. The sensitivity, specificity, and accuracy were 94.7%, 93.5%, and 97%, respectively. The results of the present study suggest that EVI2B, ATP2A2, S100B, TM4SF3, and OLFM4 could be potential prognostic markers for CRC patients.

Gene Expression Profiles for Predicting the Efficacy of the Anticancer Drug 5-Fluorouracil in Breast Cancer

Chemotherapy is an important postsurgery adjuvant therapy in the treatment of breast cancer. However, because of the individual genotype differences of patients, the drug efficacy differs from person to person, even when the same chemotherapy drug is administered. The purpose of this research was to probe the gene expression profiles to predict the efficacy of 5-fluorouracil (5-FU), the common drug used in chemotherapy for various type of cancers, in Taiwanese breast cancer patients. Microarray analysis was conducted on the cancer cell line ZR-75-1 with and without 5-FU stimulation to identify the differentially expressed genes. The significant overexpressed gene groups were selected after bioinformatics software analysis to explore the molecular mechanism of 5-FU. Six strains of breast cancer cell line purchased from American Type Culture Collection were used to analyze the expression profiles of the above target gene groups. IL18, CCL28, CXCL2, SOD1, HRAS, FDXR, and CHI3L1 genes were significantly differentially expressed in 5-FU responder and nonresponder cell lines. The selected gene groups were validated with 20 strains of breast cancer primary cultures established previously in our laboratory. The experimental results demonstrated that FAM46A, IL18, CCL28, TNF, CXCL2, PLEKHA8, HRAS, FDXR, and CHI3L1 genes showed statistically significant differential expression between primary breast cancer culture cells that respond and nonrespond to 5-FU. Six genes, IL18, CCL28, CXCL2, HRAS, FDXR, and CHI3L1, showed significant differential expression pattern in both American Type Culture Collection and primary breast cancer cultured cells. The findings of this study may serve as basis for predicting the effectiveness of 5-FU on breast cancer.

Differential gene expression profile of MAGE family in taiwanese patients with colorectal cancer.

The melanoma‐associated antigen (MAGE) gene family consists of different expression patterns in various tumor types. They are considered tumor‐specific antigens and are ideal targets for cancer immunotherapy. The purpose of this study is to identify the expression profiles of the MAGE family genes in Taiwanese colorectal cancer patients.

A Novel Technique for Detecting the Therapeutic Target, KRAS Mutant, From Peripheral Blood Using the Automatic Chipball Device With Weighted Enzymatic Chip Array

Reverse transcriptase and real-time polymerase chain reactions are widely used for the detection of gene overexpression. However, various disadvantages and limitations arise when the detection of multiple genetic targets is required. In previous studies, our laboratory successfully established a membrane array operation platform with a diagnostic biochip for the screening of gene overexpression by circulating tumor cells in cancer patients. To effectively shorten the reaction time, we improved the conventional RNA extraction method. The concept of weightedness was included in the reading procedure of the chip array and a weighted enzymatic chip array (WEnCA) platform was established. We used fluid engineering to develop a fully automatic gene chip analyzer named Chipball, which runs automatically on the WEnCA platform. The combination of the two systems is named the WEnCA-Chipball system. To understand the actual differences between the operations of WEnCA-Chipball and WEnCA-manual, we used the WEnCA-manual to analyze KRAS -associated gene overexpression in 200 samples from cancer patients to establish a cutoff value for activating the KRAS Detection Chip. Specifically, the activated KRAS expression in blood samples of 209 lung cancer patients was analyzed by both WEnCA-manual and WEnCA-Chipball and compared. The clinical applicability of WEnCAChipball was defined, including the sensitivity, specificity, and accuracy. The results showed that among 209 samples, 71 patients were positive for activated KRAS expression by WEnCA-Chipball with a sensitivity of 89%, specificity of 94%, and accuracy of 92%. In addition, the average total score of WEnCA-Chipball was 4.7 lower than that of the WEnCA-manual. The WEnCA-Chipball required an operation time of only 7.5 hours, approximately one-ninth of the WEnCA-manual operation time and one-fifth of the cost of WEnCA-manual. No significant difference was found between the detection limitations of the two systems. Great strides have been made in this development. The WEnCA-Chipball operation system has potential for clinical applications.

Polymorphisms in XPD and ERCC1 Associated with Colorectal Cancer Outcome

Using the comprehensive approach to selecting polymorphisms to date, we sought to examine whether recurrence in colorectal cancer was associated with inherited variation in three genes involved in DNA repair and cell proliferation. Three polymorphisms, which are excision repair cross-complementation 1 (ERCC1), xeroderma pigmentosum group D (XPD) and epidermal growth factor receptor (EGFR), were assessed in 257 postoperative stage II/III CRC patients with 5-fluorouracial chemotherapy in Taiwan. In addition, the correlations between genetic polymorphisms and patients’ clinicopathological features were investigated. Genotypes of XPD codon751 A/A and ERCC1 codon118 T/T were associated with regional recurrence in a statistically significant way (p = 0.018). Patients who carried XPD AA and ERCC1 TT genotypes demonstrated a significantly greater regional recurrence risk (OR = 5.625, 95% CI, 1.557–20.32). Inherited variation in XPD and ERCC1 was associated with outcome in patients with colorectal cancer in Taiwan. As the significant association of single-nucleotide polymorphisms has not been studied previously in colorectal cancer, these findings suggest novel sites of variation, in part explaining the range of treatment responses seen in this disease.

Burdock Essence Promotes Gastrointestinal Mucosal Repair in Ulcer Patients

Peptic ulcer is a common gastrointestinal disease and produces mucosa erosion. The current study assessed the ability of burdock essence to repair gastrointestinal mucosa in clinical trials. In the experimental group, two tablets of burdock essence (500 mg/tablet) were administered three times a day after meals and a placebo was administered in controls. Four weeks after drug administration, the subjects in the study underwent an assessment for the efficacy of burdock essence as health supplements before and after administration of the drug. The presence of gastric mucosal lesions was determined in all of the peptic ulcer patients using electronic endoscopy before and after taking burdock essence. A rapid urease test on tissue samples from ulcers was conducted to verify Helicobacter pylori infection. Endoscopy confirmed gastric or duodenal ulcers in 30 patients. In clinical trials of 27 patients, 20 patients took burdock essence; 17 (85%) recovered completely and three (15%) did not. Of the seven patients who took placebos, five (71%) did not completely recover and two (29%) recovered. In the experimental group, the ulcer wounds of the three patients who had taken burdock essence did not completely heal, but wounds were reduced in size by 30%, 75%, and 33%. Moreover, 10 out of 11 patients who originally were positive for H. pylori infections no longer had the pathogen by the end of the trial. These results indicate that burdock essence has an inhibitory effect on H. pylori . This study confirms that two tablets (500 mg/tablet) of burdock essence taken orally three times a day after meals can help abolish H. pylori infection and promote the therapeutic effect of conventional medication on gastric mucosal repair in gastrointestinal ulcer patients.