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Min Wu

Publications and source records attributed to Min Wu.

At least 145 records · Page 8Linked to original sources
PubMed2003

Analysis of gene expression profile induced by EMP-1 in esophageal cancer cells using cDNA Microarray.

AIM: To obtain human esophageal cancer cell EC9706 stably expressed epithelial membrane protein-1 (EMP-1) with integrated eukaryotic plasmid harboring the open reading frame (ORF) of human EMP-1, and then to study the mechanism by which EMP-1 exerts its diverse cellular action on cell proliferation and altered gene profile by exploring the effect of EMP-1. METHODS: The authors first constructed pcDNA3.1/myc-his expression vector harboring the ORF of EMP-1 and then transfected it into human esophageal carcinoma cell line EC9706. The positive clones were analyzed by Western blot and RT-PCR. Moreover, the cell growth curve was observed and the cell cycle was checked by FACS technique. Using cDNA microarray technology, the authors compared the gene expression pattern in positive clones with control. To confirm the gene expression profile, semi-quantitative RT-PCR was carried out for 4 of the randomly picked differentially expressed genes. For those differentially expressed genes, classification was performed according to their function and cellular component. RESULTS: Human EMP-1 gene can be stably expressed in EC9706 cell line transfected with human EMP-1. The authors found the cell growth decreased, among which S phase was arrested and G1 phase was prolonged in the transfected positive clones. By cDNA microarray analysis, 35 genes showed an over 2.0 fold change in expression level after transfection, with 28 genes being consistently up-regulated and 7 genes being down-regulated. Among the classified genes, almost half of the induced genes (13 out of 28 genes) were related to cell signaling, cell communication and particularly to adhesion. CONCLUSION: Overexpression of human EMP-1 gene can inhibit the proliferation of EC9706 cell with S phase arrested and G1 phase prolonged. The cDNA microarray analysis suggested that EMP-1 may be one of regulators involved in cell signaling, cell communication and adhesion regulators.

Cell Division↗
PubMed2003

Translocation of annexin I from cellular membrane to the nuclear membrane in human esophageal squamous cell carcinoma.

AIM: To investigate the alteration of the annexin I subcellular localization in esophageal squamous cell carcinoma (ESCC) and the correlation between the translocation and the tumorigenesis of ESCC. METHODS: The protein localization of annexin I was detected in both human ESCC tissues and cell line via the indirect immunofluorescence strategy. RESULTS: In the normal esophageal epithelia the annexin I was mainly located on the plasma membrane and formed a consecutive typical trammels net. Annexin I protein also expressed dispersively in cytoplasm and the nuclei without specific localization on the nuclear membrane. In esophageal cancer annexin I decreased very sharply with scattered disappearance on the cellular membrane, however it translocated and highly expressed on the nuclear membrane, which was never found in normal esophageal epithelia. In cultured esophageal cancer cell line annexin I protein was also focused on the nuclear membrane, which was consistent with the result from esophageal cancer tissues. CONCLUSION: This observation suggests that the translocation of annexin I protein in ESCC may correlate with the tumorigenesis of the esophageal cancer.

Annexin A1↗
PubMed2003

Loss of clusterin both in serum and tissue correlates with the tumorigenesis of esophageal squamous cell carcinoma via proteomics approaches.

AIM: To identify the differentially secreted proteins or polypeptides associated with tumorigenesis of esophageal squamous cell carcinoma (ESCC) from serum and to find potential tumor secreted biomarkers. METHODS: Proteins from human ESCC tissue and its matched adjacent normal tissue; pre-surgery and post-surgery serum; and pre-surgery and normal control serum were separated by two-dimensional electrophoresis (2-DE) to identify differentially expressed proteins. The silver-stained 2-DE were scanned with digital ImageScanner and analyzed with ImageMaster 2D Elite 3.10 software. A cluster of protein spots differentially expressed were selected and identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). One of the differentially expressed proteins, clusterin, was down-regulated in cancer tissue and pre-surgery serum, but it was reversed in post-surgery serum. The results were confirmed by semi-quantitative reverse-transcription (RT)-PCR and western blot. RESULTS: Comparisons of the protein spots identified on the 2-DE maps from human matched sera showed that some proteins were differentially expressed, with most of them showing no differences in composition, shape or density. Being analyzed by MALDI-TOF-MS and database searching, clusterin was differentially expressed and down-regulated in both cancer tissue and pre-surgery serum compared with their counterparts. The results were also validated by RT-PCR and western blot. CONCLUSION: The differentially expressed clusterin may play a key role during tumorigenesis of ESCC. The 2DE-MS based proteomic approach is one of the powerful tools for discovery of secreted markers from peripheral.

Aged↗
PubMed2003

Gene expression profiles of hepatoma cell line HLE.

AIM: To investigate the global gene expression of cancer related genes in hepatoma cell line HLE using Atlas Human Cancer Array membranes with 588 well-characterized human genes related with cancer and tumor biology. METHODS: Hybridization of cDNA blotting membrane was performed with (32)P-labeled cDNA probes synthesized from RNA isolated from Human hepatoma cell line HLE and non-cirrhotic normal liver which was liver transplantation donor. AtlasImage, a software specific to array, was used to analyze the result. The expression pattern of some genes identified by Atlas arrays hybridization was confirmed by reverse transcription polymerase chain reaction (RT-PCR) in 24 pairs of specimens and Northern blot of 4 pairs of specimens. RESULTS: The differential expression of cell cycle/growth regulator in hepatocellular carcinoma (HCC) showed a stronger tendency toward cell proliferation with more than 1.5-fold up-regulation of Cyclin C, ERK5, ERK6, E2F-3, TFDP-2 and CK4. The anti-apoptotic factors such as Akt-1 were up-regulated, whereas the promotive genes of apoptosis such as ABL2 were down-regulated. Among oncogene/tumors suppressors, SKY was down-regulated. Some genes such as Integrin beta 8, Integrin beta 7, DNA-PK, CSPCP, byglycan, Tenacin and DNA Topo were up-regulated. A number of genes, including LAR, MEK1, eps15, TDGF1, ARHGDIA were down-regulated. In general, expression of the cancer progression genes was up-regulated, while expression of anti-cancer progression genes was down-regulated. These differentially expressed genes tested with RT-PCR were in consistent with cDNA array findings. CONCLUSION: Investigation of these genes in HCC is helpful in disclosing molecular mechanism of pathogenesis and progression of HCC. For the first time few genes were discovered in HCC. Further study is required for the precise relationship between the altered genes and their correlation with the pathogenesis of HCC.

Base Sequence↗
PubMed2003

[Effect of expression of gut-enriched Kruppel-like factor on esophageal squamous cancer cells].

Gut-enriched Kruppel-like factor (GKLF) is a newly identified eukaryotic zinc finger protein expressed extensively in the gastrointestinal tract, and its expression is associated with growth arrest. Previous work showed that GKLF expression was down-regulated in esophageal squamous cancer. In the present work, the effects of sense and antisense expression of GKLF on the esophageal squamous cancer cell line EC9706 were observed to get more knowledge of the role of down-regulation of GKLF in the initiation and/or progression of esophageal cancer. Antisense transfection of GKLF gene in EC9706 led to decreased expression of GKLF in the cells, and these cells showed increased cell growth rate, indicating that down-regulation of the GKLF gene might contribute to cellular hyperproliferation. Both increased and decreased expression of GKLF in EC9706 by sense and antisense GKLF expression also led to the decreased adhesion of cells, suggesting a role of GKLF in the metastasis of esophageal squamous cancer. The results demonstrate that down-regulation of GKLF expression in esophageal squamous cancer causes the cancer cells to become hyperproliferative and less adhesive, and suggest that decreased expression of GKLF may contribute to the malignant phenotype of esophageal squamous cancer.

Carcinoma, Squamous Cell↗
PubMed2003

Cloning and characterization of a novel gene EC97 associated with human esophageal squamous cell carcinoma.

We report on the cloning and characterization of a novel gene EC97 which is associated with human esophageal squamous cell carcinoma (ESCC). A fragment of expressed sequence tag (EST) (aa700351) was overexpressed in ESCC tissues compared with the normal tissues in cDNA microarray data. Based on the sequence of aa700351, the full-length cDNA was acquired by polymerase chain reaction (PCR) amplification and named EC97. EC97 was 3353 bp long and its encoding protein contained 813 amino acid residues. Northern blot and reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that EC97 had a transcript of 3.4 kb in most human normal tissues we checked and its expression level was increased in 60% (12/20) of tested ESCC tissues versus the normal counterparts. EC97 was mapped to human chromosome 16p12-16p13.1 using radiation hybridization (RH) and predicted to include 25 exons and disseminated over 100 kb of genomic DNA.

Aged↗
PubMed2003

Excessive expression of the scavenger receptor class A type I can significantly affect the serum lipids.

Scavenger receptor (SR) is characterized by its ability to bind negatively charged macromolecules, particularly the modified lipoproteins that are pertinent to the development of vascular disease. To determine the role of excessive scavenger receptor A in the serum lipoprotein metabolism, transgenic mice lines with mouse scavenger receptor A gene type I (SR-AI) under the control of human SR-AI enhancer and metallothionein gene promotor were established. After zinc induction, the expression of SR-AI in transgenic mice was a little higher than the controls, but the serum lipids levels were significantly different from the controls, especially the cholesterol. These results demonstrated that overexpression of SR-AI significantly affected the serum lipids levels.

Animals↗
PubMed2003

[Association of genetic polymorphisms in the DNA repair gene XPD with risk of lung and esophageal cancer in a Chinese population in Beijing].

OBJECTIVE: XPD polymorphisms at Asp312Asn and Lys751Gln sites have been shown to modulate DNA repair capacity. The authors therefore assessed the relationship between these XPD polymorphisms and susceptibility to lung and esophageal cancer in a Chinese population via a hospital-based, case-control study. METHODS: Genotypes were determined by PCR-restriction fragment length polymorphism approaches in 383 healthy controls, 351 patients with lung cancer, and 325 patients with esophageal squamous cell carcinoma (SCC). The adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate logistic regression. RESULTS: Individuals carrying at least one 312Asn variant allele (Asp/Asn and Asn/Asn genotypes) were at an increased risk for lung SCC as compared with those with the Asp/Asp genotype (OR 1.80; 95% CI: 1.10-2.93; adjusted for age, sex and smoking), but this increased risk was not observed among patients with adenocarcinoma of the lung (adjusted OR: 1.07; 95% CI: 0.55-2.08). Furthermore, stratified analysis indicated a multiplicative interaction between tobacco smoking and the variant XPD 312Asn and 751Gln alleles on risk of lung SCC. The ORs of lung SCC for the variant XPD 312Asn and 751Gln alleles with smoking>or=29 pack/year were 12.44 (95% CI: 4.97-31.17) and 10.74 (95% CI: 4.51-25.57), respectively. No significant association between the Asp312Asn or Lys751Gln polymorphism and the risk of esophageal cancer was found. CONCLUSION: The above findings indicate that the Asp312Asn and Lys751Gln polymorphisms in the XPD locus are associated with the risk of lung SCC but not lung adenocarcinoma or esophageal SCC in this Chinese population.

Adenocarcinoma↗
PubMed2003

[Redox reactions of Sep15 and its relationship with tumor development].

BACKGROUND & OBJECTIVE: Sep15 is a selenium-containing protein identified in 1998. This protein may be involved in cancer etiology and it may have redox function. The objective of this study was to investigate the relationship between the redox function of Sep15 and tumor development. METHODS: The full-length DNA sequence of Sep15 was obtained by RT-PCR and then recombined to eukaryotic expression vector pcDNA3.1(+). The BEL-7402- Sep15 cell line, which expressed the high levels of Sep15 by transfecting the cultured hepatocarcinoma cell line BEL-7402 with pcDNA3.1-Sep15 was generated. From morphologic investigation, cell growth curve, clone formation and nude mice tumor growth curve, the relationship between Sep15 and hepatocarcinoma cell line BEL-7402 was determined. Furthermore, the redox reaction of sep15 was detected by MTT assay. RESULTS: There was no distinct effect of transfection of Sep15 gene on BEL-7402-Sep15 cell. The cell survival rate was drastically different between BEL-7402-Sep15 cell and both BEL-7402- pcDNA cell and BEL-7402-Sep15 cell after foreign H2O2 reactive oxygen stress (P<0.05). CONCLUSION: Transfecting Sep15 gene did not influence the growth characteristics of BEL-7402 cell line and Sep15 may have redox function.

Animals↗
PubMed2003

[Preparation of egg yolk immunoglobulin (IgY) against p53 protein expressed in E.coli].

OBJECTIVE: To isolate immunoglobulin (IgY) from egg yolk of p53 protein-immunized hens and to study its reactivity to the antigens. METHOD: Immunization of egg-laying hens was performed for 3 times at the interval of 14 days with purified p53 protein that had been expressed in E.coli. The eggs laid by these immunized hens were then collected during the whole period of the experiment to prepare IgY from egg yolk by ammonium sulfate precipitation. Final purification and identification of the IgY were performed using SDS-PAGE, enzyme-linked immunosorbent assay and Western blotting. RESULT: All immunized hens developed specific antibodies to p53 protein in contrast to the control ones. The highest titers of the IgY occurred 4 weeks after the first immunization and reached 1:10(6), which remained stable for up to 3 months. CONCLUSION: IgY technology is less costly, non-invasive, fast, simple and highly efficient to generate polyclonal antibodies.

Animals↗
PubMed2003

[Establishment of BAC mediated transgenic mice containing 97 kb beta-globin gene cluster].

OBJECTIVE: To delete IL-11 receptor alpha chain gene from the Bacterial Artificial Chromosome (BAC) chimeric DNA by RecA protein mediated homologous recombination method and establish the transgenic mice model containing whole beta-globin gene cluster. METHODS: Two 500 bp homologous sequences (A and B) located at the upstream and downstream of IL-11 receptor alpha chain gene respectively were cloned into the Hind III and Xba I sites of pBV vector, then the 1 kb A + B fragment was recovered from the building vector and inserted into the Sal I site of the shuttle vector pSV-RecA. After transforming the shuttle vector into the competent DH10B E. Coli containing BAC DNA, the IL-11 receptor alpha chain gene was finally deleted from the BAC DNA through chloramphenicol positive selection and fusaic acid negative selection. The new BAC clone was characterized by Pulse Field Gel Electrophoresis (PFGE). Then, we microinjected the linearized and purified BAC DNA into the mouse fertilized eggs and prepared the transgenic mice. RESULTS: By RecA protein mediated homologous recombination method, we deleted the IL-11 receptor alpha chain gene from the BAC DNA containing the complete beta-globin Gene Cluster and established 3 respective transgenic mice lines. CONCLUSION: Human beta-globin gene cluster in the transgenic mice mediated by new BAC expresses in a correct mode and level as compared with previous transgenic mice.

Animals↗
PubMed2003

[Pathogenic mechanisms of enterotoxigenic Escherichia coli in guinea pigs].

OBJECTIVE: To explore the pathogenic mechanisms of enterotoxigenic Escherichia coli (ETEC) in guinea pigs. METHODS: Pathological examination of the intestines was performed in ETEC-infected guinea pigs, and the intracellular free Ca2+ concentration, cytoplasmic pH, cell membrane potential and mitochondria membrane potential were determined immunohistochemically and by means of flow cytometry. RESULTS: The guinea pigs were sensitive to the human-origin ETEC, which caused pathological changes in the small intestines such as edema, hyperemia and lymphocyte infiltration, but no bacteria invasion into the epithelial cells was identified. Under transmission electron microscope, the ileal epithelial cells were shown with vacuolar degeneration and evidence of mitochondrial proliferation; heat-labile (LT) and heat-stable (ST) toxins pervaded in the ileal tissue, resulting in significant increase of intracellular free Ca2+ concentration, cytoplasmic pH value and cell membrane potential, with concomitance of significant decrease in mitochondrial membrane potential. CONCLUSIONS: ETEC disturbs the absorption and secretion functions of the intestinal epithelial cells, and induces extensive inflammation in the small intestines of guinea pigs. Besides their action on intestinal epithelial cells, LT and ST also affect the myocytes in the muscularis, and their action sites and mechanism might be similar. ETEC-induced diarrhea is correlated with excessive water excretion from the cells.

Animals↗
PubMed2003

[Antitumor effect of gene gun-mediated DNA vaccine pWRG-neu immunization in C57BL/6 mice].

OBJECTIVE: To investigate the inhibitory effect of DNA vaccine immunization on neu-overexpressed melanoma growth in prophylactic treatment and anti-lung-metastasis experiments in C57BL/6 mice. METHODS: pcDNA-neu transfected into B16F10 with transfection reagent Fugene 6, neu-overexpressed cell clone B16F10-neu was selected with limited dilution method. The growth curve was drawn to analyse its proliferating character in vitro. With Helios gene gun system, DNA vaccine pWRG-neu was immunized to 8-week-old C57BL/6 mice in the shaved abdominal skin for 3 times at two-weekly interval. After immunization, the life span was analyzed. Using MTT assay, the cytolysis activity of the DNA immunized mice spleen cells was compared. RESULTS: One clone of neu-overexpressed B16F10-neu was selected and its proliferating character was the same as B16F10 and B16F10-pcDNA. In prophylactic, treatment and anti-lung-metastasis experiments, gene gun-mediated pWRG-neu immunization could exhibit antitumor effects. The growth and metastasis of neu-overexpressed melanoma was reduced dramatically. The spleen cells of the immuned mice showed cytotoxic T lymphocyte (CTL) activity. CONCLUSION: Gene gun-mediated gene transfer is effective and practicable. DNA vaccine pWRG-neu is potent in preventing subsequent tumor cells challenge, inhibiting the tumor growth and metastasis.

Animals↗
PubMed2003

[Expression of annexin II in human esophageal squamous cell carcinoma].

OBJECTIVE: To evaluate the expression of annexin II in human esophageal squamous cell carcinoma (ESCC) and its relation with clinicopathological data. METHODS: The expression of annexin II mRNA and protein in paired cancer tissues and their adjacent quasi-normal tissues were detected by RT-PCR, immunohistochemical method and densitometric scanning. The relation between annexin II expression and the status of tumor differentiation was analyzed. RESULTS: The expression of annexin II was significantly lower in the tumor tissue than that in its paired normal counterpart both in mRNA and protein level (P < 0.05, P < 0.01). The protein expression of annexin II was significantly lower in moderately and poorly differentiated tumors than those in well differentiated ones (P < 0.05). CONCLUSION: Down-regulation of annexin II in esophageal carcinogenesis may play an important role in squamous cell differentiation.

Annexin A2↗
PubMed2003

[Study on serum p53 protein in cops in Guangzhou city].

OBJECTIVE: Serum p53 protein overexpression was detected in population exposed to traffic exhaust gas to study the relation between traffic exhaust gas and the increased risk in p53 gene mutation. METHODS: Serum p53 protein expression was measured by enzyme-linked immunosorbent assay. Relationship between different types of job and serum p53 protein overexpression were studied by pearson Chi-square tests. RESULTS: Results on serum p53 protein overexpression on jobs outside of office (5.74%) were not significantly higher than jobs inside the office. However, it suggested that traffic police men (12.12%) working outside of office, with whose length of service longer than 30 years had a significant overexpression of serum p53 protein than the others (5.36%) whose length of service was less than 30 years (P < 0.05, OR = 2.43, 95% CI: 1.11 - 5.33). Overexpression rate of p53 protein appeared to be 6.89% in the group whose average weekly exposure hours were more than 40 hours, which was significant higher than the group whose exposed hours were less than 40 hours (P < 0.05, OR = 1.71, 95% CI: 1.03 - 2.81). CONCLUSION: The result suggested that traffic exhaust gas was likely to cause mutation of p53 gene and increasing the incidence of lung cancer.

Adult↗
PubMed2003

[The first case of severe acute respiratory syndrome in Foshan].

OBJECTIVE: To evaluate the epidemiologic feature, diagnosis and treatment of severe acute respiratory syndrome (SARS). METHODS: To describe the epidemiologic and clinical features of the first case of SARS in Foshan city, Guangdong province retrospectively, and to review the diagnostic procedure. RESULTS: This case had the following features: (1) a history of contact with mild cats and eating the animal's meat; (2) high fever (temperature, > 38 degrees C), followed by dry cough, rapid progression to respiratory failure, followed by radiographic evidence of bilateral air-space lesions; (3) no leukocytosis; (4) spread to 4 family members who had had direct contact with this patient; (5) the patient's serum SARS virus IgG was confirmed to be positive; (6) the patient was treated with anti-viral agents, antibiotics and mechanical ventilation and molecular adsorbent re-circulating system (MARS). CONCLUSIONS: The clinical manifestations of the SARS case, which was highly infectious, met world health organization (WHO) criteria for the diagnosis of SARS. Early initiation of mechanical ventilation and supportive therapy contributed to the good prognosis of this critical case.

Adult↗
PubMed2003

[Epidemiological study of the features of the index cases in SARS case clusters].

OBJECTIVE: To understand the epidemiological characteristics of the index cases in severe acute respiratory syndrome (SARS) cases clusters and to evaluate their importance in the whole epidemic process of SARS. METHODS: Data of the index SARS cases and the subsequent case clusters were collected by means of face-to-face interview in combination with field investigation and case history consultations. RESULTS: In all three SARS clusters, the index cases all had chronic disease and played the role of infection source that transmitted the virus to the patients' family members, attending medical staff as well as other non-SARS patients sharing the same ward with them. CONCLUSION: The index cases played an important role in transmission of SARS virus among the case clusters, and their infective stages are confined within certain phases of the disease course.

Adult↗