Pancreatic adenocarcinoma is an aggressive human malignancy and is characterized by resistance to apoptosis. Recently, NADPH oxidase (Nox) 4-mediated generation of intracellular reactive oxygen ...species (ROS) was proposed to confer antiapoptotic activity and thus a growth advantage to pancreatic cancer cells. The signaling mechanism by which Nox4 transmits cell survival signals remains unclear. Here, we show that both a flavoprotein inhibitor, diphenylene iodonium (DPI), and small interfering RNAs designed to target Nox4 mRNA (siNox4RNAs) inhibited superoxide production in PANC-1 pancreatic cancer cells, and depletion of ROS by DPI or siNox4RNAs induced apoptosis. Parallely, DPI treatment and siNox4RNA transfection blocked activation of the cell survival kinase AKT by attenuating phosphorylation of AKT. Furthermore, AKT phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) on Ser-83 was reduced by DPI and siNox4RNAs. When ASK1Ser83Ala (an AKT phosphorylation-defective ASK1 mutant) was introduced into PANC-1 cells, this mutant alone induced apoptosis. But, addition of DPI or co-transfection of siNox4RNA had no additive effect, indicating that the mutant can substitute for these reagents in apoptosis induction. Taken together, these findings suggest that ROS generated by Nox4, at least in part, transmit cell survival signals through the AKT-ASK1 pathway in pancreatic cancer cells and their depletion leads to apoptosis.
Background and Aims: The roles of the virD4 and the cagG genes in the cag pathogenicity island of Helicobacter pylori for gastroduodenal pathogenesis are unclear and their roles in vivo have not been ...examined. Methods: Seven week old male Mongolian gerbils were inoculated with the wild type H pylori TN2GF4, its isogenic virD4, or cagG mutants. Animals were sacrificed at 4, 12, and 24 weeks after inoculation. Gastric inflammation and H pylori density were evaluated by histology, inflammatory response (as measured by interleukin (IL)-1β mRNA levels), proliferative activity (as assessed by 5′-bromo-2′deoxyuridine labelling indices), and host systemic reaction (as measured by anti-H pylori IgG antibody). Results: Degree of gastric inflammation, proliferative activity, and mucosal IL-1β mRNA levels remained low throughout the first 12 weeks in gerbils infected with the virD4 mutants. Degree of gastric inflammation and proliferative activity increased at 24 weeks with the virD4 mutants reaching levels comparative with those seen at four weeks with the wild-type strains. Mucosal IL-1β mRNA levels were also increased at 24 weeks with the virD4 mutants and levels at 24 weeks were similar between the wild-type and virD4 mutants. In contrast, gerbils infected with the cagG mutants had reduced ability to colonise gerbils, and no or little gastric inflammation or proliferative activity was observed. Conclusions: Loss of the virD4 gene temporally retarded but did not abrogate gastric inflammation. Loss of the cagG gene abolished gastric inflammation partially via reduced ability to colonise gerbils. Unknown factors related to the type IV secretion system other than CagA may influence gastric inflammation.
Reduced-size liver grafts from related donors may not be of an optimal size for adequate function in the recipient. Therefore, liver-graft regeneration is clinically important. We evaluated liver ...regeneration by liver-volume determinations with serial computed tomography scans in four recipients (aged 9 months to 12 years) and their donors (all fathers of the recipients) after living-related liver transplantation. Standard liver volume was calculated from the recipient's body-surface area. In each recipient, the size of the transplanted liver tended to converge to the standard liver volume with time, regardless of whether initial liver-graft volume was smaller or larger than standard liver volume. In addition, transplanted liver in the recipient regenerated much faster than remnant liver in the donor, even though both consisted of the same hepatocytes, which suggests that regeneration is regulated mainly by factors other than the hepatocytes themselves.
Despite refinements in surgical techniques for liver transplantation, liver size disparity remains one of the most common problems in pediatric patients. Optimal liver graft size remains unknown and ...the volume of diseased liver in the recipient is not indicative of the volume (standard liver volume LV) optimal for the recipient's metabolic demands. To establish a formula for calculating the standard LV in the pediatric and adult populations for liver transplantation, whole LVs were measured using computed tomography (CT) in 96 patients (65 pediatric and 31 adolescent or adult subjects) with normal liver whose disease conditions did not seem to affect body weight (BW) or LV. In the 96 subjects, the ratio of estimated LV to BW decreased gradually as age increased until approximately 16 years, when it started to level off. On the other hand, there seemed to be a directly proportional relationship between the estimated LV in vivo and body surface area (BSA) (r = 0.981; r2 = 0.962; P < 0.0001) in the subjects as a whole, and the formula, LV (mL) = 706.2 × BSA (m2) + 2.4, was established from the measured data by simple regression analysis. Another predicting equation, LV (mL) = 2.223 × BW (kg)0.426 × body height (BH) (cm)0.682, was produced by multiple regression analysis (r2 = 0.969; P < 0.0001). Considering its simplicity of use, we adopted the first formula for predicting standard LV in an individual patient.
Data regarding the chronological changes in gastric mucosal cytokines in the different phases of Helicobacter pylori infection are unavailable. We examined Mongolian gerbils for up to 52 weeks after ...H. pylori (ATCC 43504) inoculation. Levels of mRNAs of mucosal cytokines (interleukin-1{szligbeta} IL-1{szligbeta}, gamma interferon IFN-gamma, IL-4, IL-6, and IL-10) were assessed using real-time reverse transcription-PCR. Starting 26 weeks after H. pylori inoculation, two clinicohistologic patterns appeared: gastric ulcers in 32% and hyperplastic polyps in 68% of gerbils. High levels of mucosal IL-1{szligbeta} mRNA were observed early in the infection, reaching maximum at 4 weeks and then rapidly declining. Mucosal IFN-gamma mRNA also reached maximal levels at 4 weeks but remained high thereafter. Both IL-1{szligbeta} and IFN-gamma mRNA levels were consistently higher in the pyloric mucosa than in the fundic mucosa. In contrast, IL-4, IL-6, and IL-10 mRNA levels peaked at 8 to 26 weeks and levels were similar in the pyloric mucosa and the fundic mucosa. IFN-gamma mRNA levels were significantly higher in gerbils with ulcers than in those with hyperplastic polyps (median IFN-gamma/glyceraldehyde-3-phosphate dehydrogenase ratio x 100,000 = 650 versus 338, respectively antrum, and 172 versus 40, respectively corpus) (P < 0.05). We propose that the different outcomes (e.g., ulcers or hyperplastic polyps) might relate to imbalances among cytokines.
alpha 1,4-N-Acetylglucosaminyltransferase ( alpha 4GnT) is a glycosyltransferase responsible for the biosynthesis of alpha 1,4-GlcNAc-capped O-glycans, and is frequently expressed in pancreatic ...cancer cells but not peripheral blood cells. In the present study, we tested the clinical utility of alpha 4GnT mRNA expressed in the mononuclear cell fraction of peripheral blood as a biomarker of pancreatic cancer. Total RNA isolated from the peripheral blood mononuclear cells from 55 pancreatic cancer patients, 10 chronic pancreatitis patients, and 70 cancer-free volunteers was analyzed quantitatively by reverse transcription-polymerase chain reaction with primers specific for alpha 4GnT, and the expression level of alpha 4GnT mRNA relative to that of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was measured. When the ratio of alpha 4GnT to GAPDH transcripts exceeded a defined cut-off value, patients were considered to have pancreatic cancer. By these standards, 76.4% of the pancreatic cancer patients were detected by this assay. A strong correlation was obtained between positivity in this assay and the expression of alpha 4GnT protein detected immunohistochemically in pancreatic cancer tissues resected subsequently, suggesting that alpha 4GnT mRNA detected in the peripheral blood is derived from circulating pancreatic cancer cells. Although increased levels of alpha 4GnT mRNA was detected in 40.0% of chronic pancreatitis patients and 17.1% of cancer-free volunteers, the expression levels were significantly lower than those seen in pancreatic cancer patients. These results suggest that quantitative analysis of alpha 4GnT mRNA expressed in the mononuclear cell fraction of peripheral blood will contribute to the detection of pancreatic cancer. (Cancer Sci 2006; 97: 119 - 126)
Trophinin, tastin, and bystin have been identified as molecules potentially involved in human embryo implantation. Both trophoblasts and endometrial epithelial cells express trophinin, which mediates ...apical cell adhesion through homophilic trophinin-trophinin binding. We hypothesized that trophinin's function in embryo implantation is unique to humans and investigated the expression of trophinin, tastin, and bystin in ectopic pregnancy, a condition unique to humans. In tubal pregnancies, high levels of all three were found in both trophoblasts and fallopian tubal epithelia. Trophinin expression in maternal cells was particularly high in the area adjacent to the trophoblasts, whereas trophinin was barely detectable in intact fallopian tubes from women with in utero pregnancies or without pregnancies. When explants of intact fallopian tube were incubated with the human chorionic gonadotrophin (hCG), trophinin expression was enhanced in epithelial cells. Since the trophectoderm of the human blastocyst secretes hCG before and after implantation, these results suggest that hCG from the human embryo induces trophinin expression by maternal cells. As both beta-subunit of hCG and trophinin genes have diverged in mammals, the present study suggests a unique role of hCG and trophinin in human embryo implantation, including the pathogenesis of ectopic pregnancy.
Rice extract has been shown to protect gastric mucosa from stress-induced damage. In this study, the antibiotic effect and the anti-inflammatory effect of orally administered aqueous rice extract on ...Helicobacter pylori infection and H. pylori-induced gastritis, respectively, in Mongolian gerbils were investigated.
Fifty specific-pathogen-free male Mongolian gerbils, seven weeks old, were divided into four groups: uninfected, untreated animals (group A); uninfected, rice extract-treated animals (group B); H. pylori-infected, untreated animals (group C); and H. pylori-infected, rice extract-treated animals (group D). Group C and D animals were killed 12 weeks after H. pylori infection (i.e., at 19 weeks of age) and group A and B animals were also killed at age 19 weeks. The stomachs were removed for histopathological examination with hematoxylin-and-eosin staining and anti-5'-bromo-2'-deoxyuridine (BrdU) immunostaining, and to determine the bacterial burden. Serum anti-H. pylori antibody titers were also tested.
In groups A and B, the gastric mucosa showed no inflammatory cell infiltration and a few BrdU-reactive cells. Group C animals developed marked chronic active gastritis in the gastric mucosa, and BrdU-labeled cells in the gastric mucosa markedly increased in number. In group D animals, a significant reduction occurred in the degree of neutrophilic polymorphonuclear cell infiltration into the gastric mucosa, in the BrdU-labeling indices of gastric epithelial cells, and in anti-H. pylori antibody titers in the serum (P < 0.01), compared with although H. pylori was not completely eradicated.
The rice extract was effective in suppressing inflammation and epithelial cell proliferation in the gastric mucosa in H. pylori-infected Mongolian gerbils. The rice extract has potential to exhibit a protective effect on H. pylori-related gastric mucosal diseases.
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