[Prevention of restenosis with a new modified fully-covered retrievable esophageal stent].

OBJECTIVE: To observe and evaluate the effectiveness of a new modified fully-covered retrievable esophageal stent in preventing restenosis at the proximal end of the stent. METHODS: From January 2008 to October 2011, 380 consecutive patients who underwent placement of a conventional stent or a new modified stent for benign or malignant dysphagia were divided into two groups: conventional stent group 193 patients (male 137, female 56) and modified stent group 187 patients (male 125, female 62). The granulation formation and restenosis rate one month after stenting were evaluated. Data such as patient demographics, outcomes and complications were collected. The results were statistically analyzed by Student t test, chi-squared test, Fisher's exact probability or rank sum test. A P-value less than 0.05 was considered statistically significant. RESULTS: All stents were successfully implanted. They were highly effective in palliating dysphagia. The dysphagia score decreased from 3 (1) to 0 (1) in conventional stent group (P < 0.01), and that from 4 (1) to 0 (1) in modified stent group (P < 0.01). The modified stent group were superior to the conventional stent group in severe granulation formation rate (0 vs 4.7% (9/193), P = 0.004) and restenosis rate (2.7% (5/187) vs 7.3% (14/193), P = 0.041) within one month after stenting, and the modified stent was easier to retrieve. Postoperative remission rate of dysphagia, and complications such as chest pain, bleeding, perforation, stent migration had no statistical differences between the two groups (all P > 0.05). CONCLUSIONS: The new modified fully-covered retrievable esophageal stent can significantly reduce granulation formation at the proximal end of the stent. Using of this stent seems to be a better choice in treating patient of dysphagia, with lower restenosis rate and easier to retrieve.

[Effects of tumor necrosis factor-alpha inducing protein-alpha secreted by Helicobacter pylori on human gastric epithelial cells].

OBJECTIVE: To investigate the effects of tumor necrosis factor-alpha-inducing protein-alpha (Tipalpha) released from Helicobacter pylori (Hp) on human gastric epithelial cells. METHODS: Human gastric epithelial cells of the line GES-1 were cultured. Tipalpha gene located in Hp 0596 was extracted from the genome sequence of the Hp strain 26695 and its open reading frame were cloned into the eukaryotic expressing vector pcDNA3.1. The recombinant plasmid pcDNA3.1-Tipalpha thus obtained and the blank plasmid pcDNA3. 1 were transfected into the GES-1 cells, and the G418-resistent clones were screened. The GES-1 cells transfected with blank vector pcDNA3.1 and normal GES-1 cells were used as controls. RT-PCR and Western blotting were used to detect the expression of Tipalpha. The influences of Tipalpha protein on the cells proliferation, apoptosis and cell cycles, concentration of related cytokines such as TNF-alpha, IL-1beta, and IL-8, and the expression of Bcl-2 and P53 genes were respectively observed by MTT assay, flow cytometry, ELISA, and Western blotting. RESULTS: 1. A eukaryotic expression vector of Hp Tipalpha was successfully constructed. Steadily transfected strains were screened by G418. 2. MTT method showed that the growth curve of the GES-1 cells transfected with GpcDNA3.1-Tipalpha was higher, showing a faster growth. 3. Flow cytometry showed an increase in the proportion of the S-phase and a decrease in the G1-phase in the GpcDNA3.1-Tipalpha-transfected cells [(45.33 +/- 1.03)% vs (38.24 +/- 1.5)%, (33.94 +/- 1.67)%, (41.39 +/- 0.08)% vs (49.74 +/- 0.12)%, (49.27 +/- 0.15)%], and the apoptotic rate of the GpcDNA3.1-Tipalpha-transfected cells was 0.76 +/- 0.04, significantly lower than those of the GpcDNA3.1-transfected cells and non-transfected cells (16.84 +/- 2.16 and 8.36 +/- 1.07 respectively, both P < 0.05). 4. ELISA showed that there was no significant difference in intracellular TNF-alpha concentration among the 3 GES-1 cell groups (all P > 0.05), however, the extra-cellular TNF-alpha level of the GpcDNA3.1-Tipalpha-transfected cells was significantly higher than those of the 2 control groups (both P < 0.05), and that the intra- and extra-cellular IL-1beta and IL-8 concentrations of the GpcDNA3.1-Tipalpha-transfected cells were both significantly higher than those of the 2 control groups (all P < 0.05). 5. The expression level of Bcl-2 gene of the GpcDNA3.1-Tipalphac-transfected cells was obviously higher than those of the 2 control groups, and the expression of P53 gene of the GpcDNA3.1-Tipalphac-transfected cells was lower than those of the 2 control cells. CONCLUSION: The GpcDNA3.1-Tipalpha-transfected cells steadily and highly express Tipalpha protein, that induces the high expression of TNF-alpha, IL-1beta, and IL-8, proinflammatory cytokines, enhances cell proliferation, and upregulates Bcl-2 gene and down-regulates P53 gene. Tipalpha may play an important carcinogenic role in gastric cancer progression.

Common single nucleotide polymorphism of hypoxia-inducible factor-1alpha and its impact on the clinicopathological features of esophageal squamous cell carcinoma.

OBJECTIVE: Angiogenesis is one of the most important molecular events in solid tumor development and growth, in which hypoxia-inducible factor (HIF)-1alpha is a key regulator and plays an important role. Studies have shown that a single nucleotide polymorphism (C1772T) in the HIF-1alpha gene exerts a large effect on the phenotype of human head and neck squamous cell carcinoma and renal cell carcinoma. But the impact of the C1772T polymorphism on the clinicopathological features of human esophageal squamous cell carcinoma (ESCC) remains unknown, and thus it is the main focus of our study. METHODS: The C1772T genotype of 95 ESCC patients and 104 healthy controls were studied by using the polymerase chain reaction and restriction fragment length polymorphism. Mutations were confirmed by direct DNA sequencing. The impact of C1772T on tumor size, invasive depth, lymph node metastasis, distant metastasis, histological grade and TNM stage was also studied. RESULTS: The genotype frequency observed in the patients and controls was 11.58% versus 10.58%, respectively, for genotype C/T (P > 0.05). Genotype T/T was not found in our study. Larger tumors and a higher rate of lymph node metastasis was found for the C/T group. CONCLUSIONS: Although there is no significant difference of genotype distribution between ESCC patients and healthy controls, genotype C/T is associated with larger tumor and higher rate of lymph node metastasis.

Expression of COX-2 proteins in gastric mucosal lesions.

AIM: To investigate the expression of COX-2 proteins in gastric mucosal lesions and to assess the relationship between COX-2 expression and type, pathologic stage, differentiation, or lymph node metastasis in gastric cancer and the relationship between COX-2 expression and H pylori infection in gastric mucosal lesions. METHODS: Thirty patients with gastric carcinoma underwent surgical resection. Samples were taken from tumor site and paracancerous tissues, and ABC immunohistochemical staining was used to detect the expression of COX-2 proteins. H pylori was determined by rapid urea test combined with pathological stating/14C urea breath test. RESULTS: The positive rate and staining intensity of mutant COX-2 gene expression in gastric cancer were significantly higher than those in paracancerous tissues (66.7% vs 26.7%) (P<0.01, P<0.001). There was a significant correlation between COX-2 and pathologic stage or lymph node metastasis type of gastric carcinoma (76.0% vs 20.0%, 79.2% vs 16.7%) (P<0.05). No correlation was found between COX-2 expression and type or grade of differentiation (P>0.05). COX-2 expression of intestinal metaplasia (IM) or dysplasia (DYS) with positive H pylori was significantly higher than that with negative H pylori (50.6% vs 18.1%, 60.0% vs 33.3%) (P<0.05). CONCLUSION: COX-2 overexpression was found in a large proportion of gastric cancer tissues compared with matched non-cancerous tissues and was significantly associated with advanced tumor stage and lymph node metastasis. Overexpression of COX-2 plays an important role in tumor progression of gastric cancer. COX-2 may also play a role in the early development/promotion of gastric carcinoma and is associated with H pylori infection.

Expression of interleukin-22/STAT3 signaling pathway in ulcerative colitis and related carcinogenesis.

AIM: To investigate the expression of interleukin (IL)-22 and its related proteins in biopsy specimens from patients with ulcerative colitis (UC) and UC-related carcinogenesis. METHODS: Biopsy specimens were obtained from patients with inactive (n = 10), mild-to-moderately active (n = 30), severely active (n = 34), initial (n = 30), and chronic UC (n = 44), as well as UC patients with dysplasia (n = 10). Specimens from patients without colonic abnormalities (n = 20) served as controls. Chronic colitis in experimental mice was induced by 2.5% dextran sodium sulfate. The expression levels of IL-22, IL-23, IL-22R1 and phosphorylated STAT3 (p-STAT3) were determined by immunohistochemistry. Bcl-2, cyclin D1 and survivin expression was detected by Western blotting. RESULTS: Patients with active UC had significantly more IL-22, IL-23, IL-22R1 and p-STAT3-positive cells than the patients with inactive UC and normal controls. Furthermore, IL-22 and related proteins were closely related to the severity of the colitis. The expression of IL-22 and IL-22R1 in the tissue of initial UC was stronger than in that of chronic UC, whereas the expression of p-STAT3 was significantly increased in chronic UC tissues. In dysplasia tissues, the expression level of IL-22 and related proteins was higher compared with controls. Mouse colitis model showed that expression of IL-22, IL-22R1 and IL-23 was increased with time, p-STAT3 and the downstream gene were also remarkably upregulated. CONCLUSION: IL-22/STAT3 signaling pathway may be related to UC and UC-induced carcinogenesis and IL-22 can be used as a biomarker in judging the severity of UC.

Multiple genetic alterations and behavior of cellular biology in gastric cancer and other gastric mucosal lesions:H.pylori infection, histological types and staging.

AIM:To investigate the expression of multiple genes and the behavior of cellular biology in gastric cancer (GC) and other gastric mucosal lesions and their relations to Helicobacter pylori (H. pylori) infection, tumor staging and histological subtypes.METHODS:Three hundred and twenty seven specimens of gastric mucosa obtained via endoscopy or surgical resection, and ABC immunohistochemical staining were used to detect the expression of p53, p16, Bcl-2 and COX-2 proteins.H. pylori was determined by rapid urea test combined with patholo-gical staining or 14 Curea breath test. Cellular image analysis was performed in 66 patients with intestinal metaplasia (IM) and/or dysplasia (Dys). In 30 of them, both cancer and the paracancerous tissues were obtained at the time of surgery. Histolo-gical pattern, tumor staging, lymph node metastasis, grading of differentiation and other clinical data were studied in the medical records.RESULTS:p16 expression of IM or Dys was significantly lower in positive H. pylori chronic atrophic gastritis (CAG) than those with negative H. pylori (CAG: 54.8% vs 88.0%, IM:34.4% vs 69.6%, Dys: 23.8% vs 53.6%, all P < 0.05), Bcl-2 or COX-2 expression of IM or Dys in positive H. pylori cases was signi-ficantly higher than that without H. pylori (Bcl-2: 68.8% vs 23.9%, 90.5% vs 60.7%; COX-2: 50.0% vs 10.8%, 61.8% vs 17.8%; all P <0.05). The mean number of most parame-ters of cellular image analysis in positive H. pylori group was significantly higher than that in negative H. pylori group (Ellipser: 53 plus minus 14, 40 plus minus 12&mgr;m, Area(1): 748 plus minus 572, 302 plus minus 202&mgr;m(2), Area(2): 3050 plus minus 1661, 1681 plus minus 1990&mgr;m(2), all P< 0.05; Ellipseb: 79 plus minus 23, 58 plus minus 15&mgr;m, Ratio-1: 22% plus minus5%,13% plus minus4%,Ratio-2:79% plus minus17%,53% plus minus20%,all P<0.01). There was significant correl-ation between Bcl-2 and histologic pattern of gastric carcinoma, and between COX-2 and tumor staging or lymph node metasta sis (Bcl-2: 75.0% vs16.7%; COX-2: 76.0% vs 20.0%, 79.2% vs 16.7%; all P< 0.05).CONCLUSION:p16, Bcl-2, and COX-2 but not p53 gene may play a role in the early genesis/progression of gastric carcinoma and are associated with H. pylori infection. p53 gene is relatively late event in gastric tumorigenesis and mainly relates to its progression. There is more cellular-biological behavior of malignant tumor in gastric mucosal lesions with H. pylori infec-tion. Aberrant Bcl-2 protein expression appears to be preferentially associated with the intestinal type cancer. COX-2 seems to be related to tumor staging and lymph node metastasis.