Biomedical subjects

Zi-ming Dong

Publications and source records attributed to Zi-ming Dong.

6 recordsLinked to original sources

PubMed2006

[The properties of exosomes secreted by human umbilical cord blood dendritic cells and its enhancement of CTL cytotoxicity].

AIM: To investigate the properties of exosomes secreted by dendritic cells(DCs) derived from human umbilical cord blood mononuclear cells(HUBMCs) and its enhancement of CTL cytotoxicity. METHODS: The HUBMCs were separated from human umbilical cord blood(HUCB). The generation of DCs were induced for 12 days in medium containing SCF, IL-4 and GM-CSF. Tumor antigen extracted by repeated freeze-thawing were added to culture medium and cultured successively for 2 days. The DCs were collected and exosomes were separated from culture supernatant through centrifugation at 100,000 g. The exosomes-associated properties were analyzed by FCM, SDS-PAGE, transmission electron microscope(TEM) and MTT colorimetry. RESULTS: After being induced for 12 days with SCF, IL-4 and GM-CSF the number of DCs had a 10-fold increase and displayed typically morphological characteristics of DCs. FCM analysis showed that the DCs loaded with tumor antigen expressed highly MHC-I, MHC-II, CD40, CD80, CD86, CD11c and CD54. Exosomes could be separated from culture supernatant of DCs by ultracentrifugation. Mixed lymphocyte reation(MLR) and cytotoxicity assay showed that exosomes secreted by DCs could effectively stimulate T cell proliferation and enhance their cytotoxicity. CONCLUSION: A large number of DCs are obtained from UBMCs and the exosomes are secreted from them in vitro. The exosomes can present tumor antigen to T cells and enhance the cytotoxicity of CTLs.

B7-1 Antigen↗

PubMed2006

[cDNA microarray-based study of gene expression profile changes in human esophageal squamous cell carcinoma].

OBJECTIVE: To investigate the differentially expressed genes between human esophageal squamous cell carcinoma (ESCC) and normal esophageal mucosa and explore an effective method with high throughput for screening the molecular markers closely correlated with the development, invasion and metastasis of ESCC. METHODS: With cDNA microarray and laser capture microdissection, T7-based amplification were used to detect the mRNA from both the primary carcinoma and the corresponding esophageal epithelium in 15 ESCC cases, and the results were analyzed by bioinformatics methods. RESULTS: Among the 886 target genes, 110 (12.42%) genes were differentially expressed commonly at least twice in all the 15 samples, including 56 (6.32%) up-regulated by at least 2 folds and 54 (6.09%) down-regulated by at least 0.5 folds. CONCLUSION: Many ESCC-associated genes were screened by the high-throughput gene chip method, and functional study of these genes may help to identify the key genes or pathways involved in the pathogenesis and development of ESCC.

Carcinoma, Squamous Cell↗

PubMed2006

[Expressions of estrogen receptor subtypes in epithelial ovarian carcinomas].

OBJECTIVE: To investigate the expressions of estrogen receptor(ER) subtypes ERa and ERP in epithelial ovarian carcinomas. METHODS: One hundred and eighteen Norwegian patients with epithelial ovarian carcinoma were included in this study. The expressions of ERalpha and ERbeta were examined by means of immunohistochemistry. The relationships between protein expressions and clinicopathological features and survival were analyzed. Frozen tissues from 10 cases in which the tumors showed variable ERalpha and ERbeta protein expressions were used for Laser capture microdissection (LCM). Cancer cells in each frozen section were captured with the LCM method and processed for Western blot analysis. RESULTS: Of the 118 tumours, 32 (27.1%), 20 (16.9%), 17 (14.4%), 49 (41.5%) demonstrated negative, weak, moderate and strong expression of ERalpha protein, respectively; 1 (0.8%), 7 (5.9%), 13 (11%), 97 (82.2%) showed negative, weak, moderate and strong expressions of ERbeta protein, respectively. There was no significant association between ERalpha expression and the clinicopathological features such as age, histological type, FIGO stage, histological grade and residual tumour size. ERbeta expression was not associated with age, histological type,FIGO stage and residual tumour size, but it was significantly associated with higher histological grade. In addition, Kaplan-meier analysis revealed that high levels of ERbeta expression was significantly associated with a shorter overall survival (P = 0.03). CONCLUSION: There are ERalpha and ERbeta expressions in epithelial ovarian carcinomas. Higher level of ERbeta protein expression is associated with higher histological grade and poorer clinical outcome in the cases of ovarian carcinoma. ERbeta may be a useful marker of ovarian carcinogenesis and could predict the efficacy of endocrinotherapy and the prognosis for patients with ovarian carcinoma.

Adult↗

PubMed2006

[Study on the association of polymorphisms in homocysteine metabolism related enzymes with deep venous thrombosis].

OBJECTIVE: To explore the significance of gene mutation of methylenetetrahydrofolate reductase (MTHFR) C677T, methionine synthase (MS) 2756 AG and cystathionine beta-synthase (CBS) 844ins68 in the development of deep venous thrombosis. METHODS: One hundred and three cases of deep venous thrombosis (DVT group) and 250 healthy subjects (control group) were recruited in the study. The polymorphisms of MTHFR C677T, MS A2756G and CBS 844ins68 were detected by PCR-restriction fragment length polymorphism(PCR-RFLP). RESULTS: The prevalences of TT genotypes of MTHFR (C677T) between DVT group and normal control group had significant difference (27.2% vs 17.2%, P< 0.05), the prevalence of AG genotypes of MS A2756G in the DVT group was less than that in the control group (9.7% vs 19.2%, P< 0.05). The prevalence of 677T-2756A haplotype in the DVT group was higher than that in the control group (P< 0.05), the prevalence of 677C-2756A haplotype in the DVT group was less than that in the control group (P< 0.05). There were no significant differences in the prevalences of CBS 844ins68 mutation. CONCLUSION: The homozygote of MTHFR C677T (TT) may be a risk factor of DVT. MS A2756 G(AG) genotypes may reduce the development of DVT. The 677T-2756A haplotype may be a risk factor of DVT. The 677C-2756A haplotype may be a protective factor of DVT. The prevalence of gene mutation of CBS 844ins68 might vary with different ethnic group or geographic regions.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

PubMed2004

[Rapid detection of the genotyping of hepatitis C virus using DNA chip with coloration methods].

OBJECTIVE: To develop a new DNA chip with coloration, which can be used for rapid and economical detection of the genotyping of hepatitis C virus (HCV). METHODS: Probes and primers were designed according to the sequence of HCV 5' non-coding region (5' NCR) to fabricate DNA chip. Experimental group consisted of 60 positive serum samples and control group consisted of 20 negative serum samples. To obtain the aimed gene, then they were hybridized with DNA chip. Finally, the results showed in a nylon film. The results of DNA sequencing of samples were used as the control in double blind experimental. RESULTS: Using DNA chip, HCV was detected in positive of all serum specimens of experimental group and negative in control group. The determination of HCV genotype by DNA chip showed corresponding rate of 96.7% with those by sequence assay. CONCLUSION: It showed higher specialty and sensitivity using DNA chip to detect the genotype of HCV. It would be valuable for the clinical genotyping of HCV

5' Untranslated Regions↗

PubMed2003

[Study on DNA polymerase beta gene mutation in human cervical cancer].

OBJECTIVE: To investigate whether DNA polymerase beta (POLB) gene mutations occur in human cervical cancer (CC). METHODS: To collect fresh specimens from 34 cervical cancer and examine the mutation of POLB gene using reverse transcription polymerase chain reaction (RT-PCR), single strand conformation polymorphism (SSCP) analysis and sequence analysis. According to their histological grading, the 34 cases of CC were divided into three groups: 9 cases of grade I (G(1)), 14 cases of grade II (G(2)), 11 cases of grade III (G(3)). RESULTS: POLB mutations were detected in the tissues of CC. The mutation of POLB is related with the histological differentiated of the CC. The mutated rates in low differentiated cancer were significantly higher than those in moderate and high ones, and the difference was significant (P < 0.05). The sequencing of the PCR product showed an A to G chang at nucleotide 660, which resulted in a substitution of the amino acid from arginine to glycin at codon 182. CONCLUSIONS: There were POLB mutations in the tissues of CC, and this may be related with the development of the CC. The mutations impaired the catalytic activity of POLB. As a result, this may lead to observed accumulation of mutations in tumor cells.

DNA Polymerase beta↗