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Hui-Mian Xu

Publications and source records attributed to Hui-Mian Xu.

10 recordsLinked to original sources
PubMed2005

Inducible nitric oxide synthase, nitrotyrosine and apoptosis in gastric adenocarcinomas and their correlation with a poor survival.

AIM: To detect the presence of inducible nitric oxide synthase (iNOS), nitrotyrosine (NT) and apoptosis in gastric adenocarcinomas and their possible correlations with the clinicopathological characteristics and prognosis of gastric adenocarcinoma. METHODS: Sixty-six specimens of gastric adenocarcinoma and corresponding adjacent normal gastric tissues were studied. Immunohistochemistry was employed to localize iNOS and NT protein and an immunohistochemical scoring system was used. The occurrence of apoptotic cell death (apoptotic index (AI)) was analyzed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick-end labeling (TUNEL) method. RESULTS: Results showed that iNOS expression was detected at an intermediate or high level in 41 of 66 (62%) specimens of gastric adenocarcinoma. NT expression was 58%. Neither of them was found in the normal gastric tissues; there were significant positive correlations among iNOS expression, NT expression and AI. Many clinicopathologic characteristics of gastric adenocarcinoma, such as tumor size, depth of invasion, lymph node metastasis and TNM staging, were related to iNOS and NT expressions (P<0.05). In 66 surviving patients, the 5-year survival rate of 41 patients who had tumors with intermediate or high iNOS expressions and high AIs (4.09%; 19.96%) was significantly lower than that of 25 patients who had tumors with negative or low iNOS expressions and low AIs (0.79%; 47.14%) (P = 0.001). COX's multivariate analysis revealed that the iNOS expression was identified as one of the significant independent prognostic factors predictive of a poor survival (relative risk (RR) = 2.69). CONCLUSION: NO produced by iNOS may play a stronger role in promoting gastric adenocarcinoma growth than in suppressing its growth. iNOS and NT expressions by gastric adenocarcinoma may correlate with a poor survival.

Adenocarcinoma↗
PubMed2005

[The relationship between the expressions of interleukin-8 and cyclooxygenase-2 and the type of anastomosis in the remnant stomach].

OBJECTIVE: To study the expressions and the significance of interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2) in the remnant stomach. METHODS: Fifty-eight patients with gastrectomy were examined by upper gastrointestinal endoscopy. Two biopsy specimens were obtained from the stoma and the upper corpus gastric mucosa in the remnant stomach. mRNA was extracted from biopsy specimens to measure the IL-8 and COX-2 gene mRNA levels by real-time PCR method. RESULTS: IL-8 and COX-2 levels were higher in stoma than in corpus, IL-8 levels in BI anastomosis were significantly higher in stoma than in corpus (P< 0.05). In Hp-negative patients, IL-8 and COX-2 levels in stoma were significantly higher in BII anastomosis than in BI anastomosis (P < 0.05). In Hp-positive patients, IL-8 and COX-2 levels in stoma showed no significant differences between BII anastomosis and BI anastomosis. In corpus, IL-8 and COX-2 levels in Hp-positive patients were significantly higher than those in Hp-negative patients, (P < 0.05), including in BI anastomosis and in BII anastomosis. CONCLUSIONS: The risk of the secondary stomach carcinogenesis in stoma after distal gastrectomy is higher than that in corpus; The types of anastomosis may influence the risk for the secondary stomach carcinogenesis in the remnant stomach mucosa.

Adult↗
PubMed2005

Linkage disequilibrium and haplotype analysis of two single nucleotide polymorphisms in STK15 in Chinese.

STK15 (Serine/Threonine protein kinase 15) is a serine/threonine kinase encoding gene, whose overexpression in mammalian cells leads to centrosome amplification, chromosomal instability, and oncogenic transformation. 91A-->T, a single nucleotide polymorphism (SNP) in exon 3 of STK15, has recently been shown to be associated with human cancer susceptibility. Within exon 3 of STK15, there are three nonsynonymous SNPs: 91 A-->T, 169G-->A and 311C-->T. We have determined STK15 genotypes and haplotypes composed of 91A-->T and 169G-->A by PCR-RFLP in a randomly sampled cohort of 193 normal individuals from Northeast China. DNA samples from all individuals were subjected to first round of PCR using a pair of specific primers. For the subsequent nested PCR,a mismatch forward primer, which could introduce an EcoR I restriction site to the 91A allele, was included. The nested PCR products were digested with the restriction endonucleases EcoRI and AccII. The double restriction digests were separated by polyacrylamide gel electrophoresis. Three haplotypes,91A-169G, 91T-169A and 91T-169G, were detected and their frequencies were 68.65%, 10.88% and 20.47%, respectively. Six genotypes composed of the above three haplotypes were found,and their frequencies were 91A-169G/91 A-169G (46.11%), 91A-169G/91 T-169A (14.51%), 91A-169G/91T-169G (30.57%), 91T-169G/91T-169G (3.11%), 91T-169G/91T-169A (4.15%), 91T-169A/91T-169A (1.55%). Whereas no 91A-169A haplotype was detected in all individuals examined in the current study, linkage disequilibrium (LD) between the two SNPs was found.

Alleles↗
PubMed2004

Expression of survivin in primary and metastatic gastric cancer cells obtained by laser capture microdissection.

AIM: Survivin, a recently identified member of the inhibitor of apoptosis protein family, is expressed during development and in various human cancers. However, its expression in normal tissues and clinical relevance in cancers are still debated. In the present study, we analyzed the expression of the survivin gene in human primary and metastatic gastric cancer cells as well as in paired epithelial cells from normal gastric mucosa by means of a novel laser capture microdissection (LCM) technique coupled with reverse transcription-polymerase chain reaction (RT-PCR). METHODS: Thirty patients who had undergone gastrectomy with lymph node dissection for gastric cancer without preoperative treatments were included. Neoplastic tissue, metastatic lymph nodes, and apparently uninvolved normal tissue were collected from each patient. LCM-captured "pure" cell groups were respectively subjected to RT-PCR analysis with primers specific for the survivin gene. RESULTS: Of the paired samples from 30 gastric cancer patients studied, 24 (80%) primary gastric cancer cell groups and 7 (23%) adjacent morphologically "normal" gastric epithelial cell groups were shown to have a detectable survivin expression. There was a statistically significant difference in suvivin expression between these two groups (P<0.01). Meanwhile, 95% (19/20) of the metastatic gastric cancer cell groups from lymph nodes had a clear expression of te survivin gene. However, no significant correlation between survivin expression and clinicopathological features of gastric cancer was observed in the present study. CONCLUSION: Survivin expression is present in the majority of gastric cancer cell groups obtained by LCM techniques. The high expression rate in metastatic lesions suggests a possible role of survivin in cancer invasiveness and metastasis. It may contribute to the detection of gastric cancer micrometastasis as a potential molecular marker. In addition, the high expression percentage renders survivin a potential target in the therapy for gastric cancer.

Adult↗
PubMed2003

Somatic mutation analysis of p53 and ST7 tumor suppressor genes in gastric carcinoma by DHPLC.

AIM: To verify the effectiveness of denaturing high-performance liquid chromatography (DHPLC) in detecting somatic mutation of p53 gene in gastric carcinoma tissues. The superiority of this method has been proved in the detection of germline mutations, but it was not very affirmative with respect to somatic mutations in tumor specimens. ST7 gene, a candidate tumor suppressor gene identified recently at human chromosome 7q31.1, was also detected because LOH at this site has also been widely reported in stomach cancer. METHODS: DNA was extracted from 39 cases of surgical gastric carcinoma specimen and their correspondent normal mucosa. Seven fragments spanning the 11 exons were used to detect the mutation of p53 gene and the four exons reported to have mutations in ST7 gene were amplified by PCR and directly analyzed by DHPLC without mixing with wild-type allele. RESULTS: In the analysis of p53 gene mutation, 9 aberrant DHPLC chromatographies were found in tumor tissues, while their normal-adjacent counterparts running in parallel showed a normal shape. Subsequent sequencing revealed nine sequence variations, 1 polymorphism and 8 mutations including 3 mutations not reported before. The mutation rate of p53 gene (21%) was consistent with that previously reported. Furthermore, no additional aberrant chromatography was found when wild-type DNA was added into the DNA of other 30 tumor samples that showed normal shapes previously. The positivity of p53 mutations was significantly higher in intestinal-type carcinomas (40%) than that in diffuse-type (8.33%) carcinomas of the stomach. No mutation of ST7 gene was found. CONCLUSION: DHPLC is a very convenient method for the detection of somatic mutations in gastric carcinoma. The amount of wild type alleles supplied by the non-tumorous cells in gastric tumor specimens is enough to form heteroduplex with mutant alleles for DHPLC detection. ST7 gene may not be the target gene of inactivation at 7q31 site in gastric carcinoma.

Base Sequence↗
PubMed2003

[Genomic variations in the locus for aminopeptidase N:a putative cellular receptor for SARS-CoV spike glycoprotein].

Aminopeptidase N has been identified as the cellular receptor for human coronavirus HCoV-229E and was a putative receptor for the spike glycoprotein encoded by the SARS-associated coronavirus (SARS-CoV). We report here identification of 9 single nucleotide polymorphisms (SNPs) in ANPEP, encoding human aminopeptidase N, in Chinese. All ANPEP exons and their flanking intronic sequences were amplified from unrelated normal individuals by polymerase chain reaction (PCR) and screened using denaturing high-performance liquid chromatography (DHPLC). Nine SNPs were revealed after direct sequencing of PCR amplified fragments which showed changes of DHPLC chromatogram. Four of these polymorphisms, T321M(962C > T), S651L(1952C > T), S752N(2255G > A) and G764R(2290G > A), were non-synonymous; the remaining exonic synonymous and intronic ones were T795T(2385C > T), IVS7 + 17G > A, IVS14-16A > G, IVS17 + 12C > G and IVS17 + 44C > T. Our data may be useful for studies to investigate the role of host genetic factors in SARS pathogenesis, especially for identifying SARS-susceptible and/or anti-SARS alleles.

Animals↗
PubMed2003

[The I1307K mutation and protein expression of APC gene in gastric cancer].

In order to explore the correlation of the abnormalities of tumor suppressor gene APC with the carcinogenesis and progression of gastric cancer. The I1307K mutation of APC gene in gastric cancer was analysed using Amplification Refractory Mutation System PCR(ARMS ,PCR),also the expression of APC protein in gastric cancer of different stages was detected by immunohistochemical method. We found that there wasn't I1307K mutation of APC gene in 62 cases of blood samples of susceptible population in high incidence areas of gastric cancer and 45 cases of gastric cancer tissues. The positive rates of APC protein in gastric cancer (both early and progressive gastric cancer) were significantly lower than that in normal mucosa,the positive rates of APC protein in progressive gastric cancer were significantly lower than that in early gastric cancer,the positive rates of APC protein in gastric cancer with lymph node metastasis were significantly lower than that in gastric cancer without lymph node metastasis. So it was thought that there might be no correlation between the I1307K mutation of APC gene and carcinogenesis of gastric cancer in China,but the decreased expression of APC protein was closely related to the carcinogenesis,progression and lymph node metastasis of gastric cancer.

English Abstract↗
PubMed2003

[Optimization of cDNA microarray fabrication].

To optimize and screen the most suitable target gene length,concentration and printing solution in cDNA microarray, housekeeping genes, such as beta actin and GAPDH, were selected as targets and hepatitis B virus gene as negative control. The RT-PCR primers that spanned at least one intron and whose products were at between 189 bp and 1078 bp were designed with primer premier 5.0, so did the hepatitis B virus gene PCR primer. After polymerase chain reaction, the products were purified with ethanol and dissolved in 3xSSC, 50% DMSO and 0.5 mol/L carbonate buffer(pH=9.0)respectively. The concentrations of target genes were adjusted at 0.5 microg/microL, 1.0 microg/microL and 1.5 microg/microL. The hybridization signals had a good specificity. No signal showed in either negative control (HBV) or blank control (printing solution only). There was no significant difference in target gene lengths. The P value of beta actin (189 bp,491 bp,974 bp) and GAPDH (227 bp,552 bp,1078 bp) was 0.378 and 0.866 respectively. There was no significant difference among concentrations(P=0.648),too. However, the higher the concentration was, the stronger the signals would be. Among the three kinds of printing solution, 50% DMSO was the best (P=0.0001), while the other two had no difference by multi-comparison (P=0.142). The target gene at length between 200 bp and 1000 bp has got the same hybridization signals.50% DMSO printing solution and the target gene concentration of 0.5 microg/microl are suitable for good hybridization.

English Abstract↗