Relative risk factors associated with the development of fundic gland polyps.

OBJECTIVES: The prevalence of fundic gland polyps (FGPs) is increasing. Some researchers consider this increase to be associated strongly with the long-term use of proton-pump inhibitors (PPIs); however, not all researchers share this belief. There are minimal data on the development of FGPs in China. Therefore, we aimed to investigate the prevalence of FGPs and risk factors associated with the development of this disease. MATERIALS AND METHODS: We studied 10 904 consecutive patients who underwent gastroduodenal endoscopies at our digestive endoscopy center between February 2011 and January 2013. Information on sex, age, Helicobacter pylori infection, PPIs intake, and the pathological results of the polyps were collected in the FGPs group and in the control group. The use of PPIs, sex, and H. pylori infection were statistically evaluated as dichotomous variables using a χ-test; age was evaluated as a continuous variable using a t-test. Finally, these factors were evaluated using a multiple logistic regression analysis. RESULTS: Gastric polyps were found in 759 (7.0%) patients, and 213 (2.0%) of these patients had FGPs. FGPs accounted for 28.1% of the gastric polyps. In the FGPs group, the percentage of H. pylori infection was 66.8% and the percentage of PPIs intake for at least 12 months was 23.1%. In the control group, the percentage of H. pylori infection was 77.4% and the percentage of PPIs intake for at least 12 months was 2.3%. The difference in the long-term use of PPIs was statistically significant between these two groups [χ=33.98, P<0.05, odds ratio (OR)=12.83, 95% confidence interval (CI): 4.47-36.80]. The results of the logistic regression were as follows: long-term use of PPIs (P<0.01, OR=14.11, 95% CI: 4.15-47.93); age (P<0.01, OR=1.69, 95% CI: 1.31-2.18). The P-values for sex and H. pylori infection were higher than 0.05. CONCLUSION: Age and the long-term use of PPIs were risk factors for the presence of FGPs; the long-term use of PPIs was a particularly strong risk factor.

[Effect of NK4 gene transfection on tumor growth of human pancreatic cancer xenograft in nude mice].

BACKGROUND & OBJECTIVE: NK4 is not only an antagonist of hepatocyte growth factor but also an angiogenesis inhibitor. Studies have confirmed that NK4 can inhibit tumor growth and metastasis, but its effect on pancreatic cancer remains unknown. This study was designed to observe the effect of NK4 gene on human pancreatic cancer in nude mice and the possible mechanisms. METHODS: The nude mouse model of pancreatic cancer was established with human pancreatic cancer cell line SW1990. The eukaryotic expression vector of NK4 gene was constructed and transfected into the tumors. The mice weight, tumor size and volume were measured before and after transfection. The apoptotic cells, microvessel density (MVD), and the expression of proliferating cell nuclear antigen (PCNA) in the tumors were observed using immunohistochemistry and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) technique. RESULTS: Four weeks after NK4 gene transfection, the tumor volume and weight was significantly smaller in NK4-transfected group than in PBS control group and empty vector group [(1.39+/-0.33) cm(3) vs. (2.06+/-0.55) cm(3) and (1.90+/-0.36) cm(3), P<0.01; (1.30+/-0.81) g vs. (3.45+/-1.88) g and (3.14+/-1.51) g, P<0.01]; the inhibition rate was 62.29%. The tumor cell apoptotic index was significantly higher in NK4-transfected group than in the rest 2 groups (9.34+/-0.91 vs. 4.13+/-0.79 and 3.94+/-1.03, P<0.001); the MVD was significantly lower in NK4-transfected group than in the rest 2 groups (12.24+/-4.63 vs. 20.13+/-7.00 and 19.70+/-6.15, P<0.05); the expression of PCNA in NK4-transfected group was not different from those of the rest 2 groups (53.88+/-4.30 vs. 56.24+/-4.03 and 54.33+/-5.41,P>0.05). CONCLUSION: NK4 gene transfection may inhibit the growth of human pancreatic cancer in mouse model through suppressing angiogenesis and enhancing the apoptosis of pancreatic cancer cells.

[Effect of transferred NK4 gene on biological characteristics of human pancreatic cancer cell line SW1990].

BACKGROUND & OBJECTIVE: Hepatocyte growth factor (HGF) plays an important role in the regulation of migration, invasion,and angiogenesis of cancer via the activation of its receptor, c-Met. NK4 is not only an antagonist of HGF but also an angiogenesis inhibitor. The blockade of HGF/c-Met signal pathway and tumor angiogenesis may be a new strategy for cancer treatment. This study was designed to construct eukaryotic expressing vector of NK4 gene, transfer it into human pancreatic cancer cell line SW1990, and observe the effect of transfected NK4 gene on the biological behaviors of SW1990 cells,and its expression in SW1990 cells. METHODS: The recombinant of pcDNA3/hNK4 plasmid was digested by restrictive enzyme,NK4 gene was cloned into a high effective eukaryotic expressing vector pRC/CMV2, and the recombinant of pRC/CMV2-hNK4 plasmid was transiently introduced into SW1990 cells by lipofectamine. Reverse transcriptase-polymerase chain reaction (RT-PCR),and Western blot were used to detect the expression of NK4 at mRNA, and protein levels,respectively. Migration, and invasion capabilities of the transfected cells were evaluated by Transwall chamber, and Matrigel invasion chamber, respectively. RESULTS: Expressions of NK4 gene after lipofectamine mediated transfection were observed in SW1990 cells, expected fragment of 453 bp has been amplified by RT-PCR, and Western blot analysis showed positive expression of NK4 protein (50 KDa). NK4 gene had no inhibitory effect on the growth of SW1990 cells (2.2x10(5) vs 2.5x10(5), P >0.05), while it had significantly suppressive effect on the migration and invasion of SW1990 cells driven by HGF or fibroblasts (P< 0.01). CONCLUSION: NK4 gene transfection may inhibit spreading and invasion of pancreatic cancer cells, which would play an important role in the anti-metastasis therapy for pancreatic cancer.