E-cadherin is an important adhesion molecule whose loss is associated with progression and poor prognosis of liver cancer. However, it is unclear whether the loss of E-cadherin is a real culprit or a ...bystander in liver cancer progression. In addition, the precise role of E-cadherin in maintaining liver homeostasis is also still unknown, especially in vivo. Here we demonstrate that liver-specific E-cadherin knockout mice develop spontaneous periportal inflammation via an impaired intrahepatic biliary network, as well as periductal fibrosis, which resembles primary sclerosing cholangitis. Inducible gene knockout studies identified E-cadherin loss in biliary epithelial cells as a causal factor of cholangitis induction. Furthermore, a few of the E-cadherin knockout mice developed spontaneous liver cancer. When knockout of E-cadherin is combined with Ras activation or chemical carcinogen administration, E-cadherin knockout mice display markedly accelerated carcinogenesis and an invasive phenotype associated with epithelial–mesenchymal transition, up-regulation of stem cell markers, and elevated ERK activation. Also in human hepatocellular carcinoma, E-cadherin loss correlates with increased expression of mesenchymal and stem cell markers, and silencing of E-cadherin in hepatocellular carcinoma cell lines causes epithelial–mesenchymal transition and increased invasiveness, suggesting that E-cadherin loss can be a causal factor of these phenotypes. Thus, E-cadherin plays critical roles in maintaining homeostasis and suppressing carcinogenesis in the liver.
Interleukin-6 (IL-6) is a pleiotropic cytokine that affects various functions, including tumor development. Although the importance of IL-6 in gastric cancer has been documented in experimental and ...clinical studies, the mechanism by which IL-6 promotes gastric cancer remains unclear. In this study, we investigated the role of IL-6 in the epithelial-stromal interaction in gastric tumorigenesis. Immunohistochemical analysis of human gastritis, gastric adenoma, and gastric cancer tissues revealed that IL-6 was frequently detected in the stroma. IL-6-positive cells in the stroma showed positive staining for the fibroblast marker α-smooth muscle actin, suggesting that stromal fibroblasts produce IL-6. We compared IL-6 knockout (IL-6(-/-)) mice with wild-type (WT) mice in a model of gastric tumorigenesis induced by the chemical carcinogen N-methyl-N-nitrosourea. The stromal fibroblasts expressed IL-6 in tumors from WT mice. Gastric tumorigenesis was attenuated in IL-6(-/-) mice, compared with WT mice. Impaired tumor development in IL-6(-/-) mice was correlated with the decreased activation of STAT3, a factor associated with gastric cancer cell proliferation. In vitro, when gastric cancer cell line was co-cultured with primary human gastric fibroblast, STAT3-related genes including COX-2 and iNOS were induced in gastric cancer cells and this response was attenuated with neutralizing anti-IL-6 receptor antibody. IL-6 production from fibroblasts was increased when fibroblasts were cultured in the presence of gastric cancer cell-conditioned media. IL-6 production from fibroblasts was suppressed by an interleukin-1 (IL-1) receptor antagonist and siRNA inhibition of IL-1α in the fibroblasts. IL-1α mRNA and protein were increased in fibroblast lysate, suggesting that cell-associated IL-1α in fibroblasts may be involved. Our results suggest the importance of IL-6 mediated stromal-epithelial cell interaction in gastric tumorigenesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Polyphenols are representative bioactive substances with diverse biological effects. Here, we show that apigenin, a flavonoid, has suppressive effects on microRNA (miRNA) function. The effects were ...mediated by impaired maturation of a subset of miRNAs, probably through inhibition of the phosphorylation of TRBP, a component of miRNA-generating complexes via impaired mitogen-activated protein kinase (MAPK) Erk activation. While glucose intolerance was observed in miRNA103 (miR103)-overexpressing transgenic mice, administration of apigenin improved this pathogenic status likely through suppression of matured miR103 expression levels. These results suggest that apigenin may have favorable effects on the pathogenic status induced by overexpression of miRNA103, whose maturation is mediated by phosphorylated TRBP.
Mitogen-activated protein kinase (MAPK) pathways regulate multiple cellular functions and are highly active in many types of human cancers. Apoptosis signal-regulating kinase 1 (ASK1) is an upstream ...MAPK involved in apoptosis, inflammation, and carcinogenesis. This study investigated the role of ASK1 in the development of gastric cancer. In human gastric cancer specimens, we observed increased ASK1 expression, compared to nontumor epithelium. Using a chemically induced murine gastric tumorigenesis model, we observed increased tumor ASK1 expression, and ASK1 knockout mice had both fewer and smaller tumors than wild-type (WT) mice. ASK1 siRNA inhibited cell proliferation through the accumulation of cells in G1 phase of the cell cycle, and reduced cyclin D1 expression in gastric cancer cells, whereas these effects were uncommon in other cancer cells. ASK1 overexpression induced the transcription of cyclin D1, through AP-1 activation, and ASK1 levels were regulated by cyclin D1, via the Rb—E2F pathway. Exogenous ASK1 induced cyclin D1 expression, followed by elevated expression of endogenous ASK1. These results indicate an autoregulatory mechanism of ASK1 in the development of gastric cancer. Targeting this positive feedback loop, ASK1 may present a potential therapeutic target for the treatment of advanced gastric cancer.
Hepatocellular carcinoma (HCC) is a threat to public health worldwide. We previously identified the association of a single nucleotide polymorphism (SNP) at the promoter region of the MHC class I ...polypeptide-related sequence A (MICA) gene with the risk of hepatitis-virus-related HCC. Because this SNP affects MICA expression levels, regulating MICA expression levels may be important in the prevention of HCC. We herein show that the microRNA (miR) 25-93-106b cluster can modulate MICA levels in HCC cells. Overexpression of the miR 25-93-106b cluster significantly suppressed MICA expression. Conversely, silencing of this miR cluster enhanced MICA expression in cells that express substantial amounts of MICA. The changes in MICA expression levels by the miR25-93-106b cluster were biologically significant in an NKG2D-binding assay and an in vivo cell-killing model. These data suggest that the modulation of MICA expression levels by miRNAs may be a useful method to regulate HCCs during hepatitis viral infection.
Background
Diabetes mellitus (DM) has long been recognized as a risk factor for pancreatic cancer (PaC) and recently has attracted attention as a manifestation of PaC. Diabetes is expected to be a ...clue for the early detection of PaC; however, no effective screening strategy has been established.
Methods
Forty diabetic patients with PaC were identified and compared with 120 diabetic patients without any malignancies. We analyzed risk factors for and early signs of PaC, focusing on the DM-onset age.
Results
As there were peaks at 40–45 years and 60–65 years in the distribution of DM-onset age, we analyzed the clinical characteristics of and risk factors for PaC according to DM-onset age: i.e., early-onset (<55 years) and late-onset (≥55 years). PaC was diagnosed within 2 years of DM onset (new-onset) in 0 % of the patients with early-onset DM, and in 33 % of those with late-onset DM. The mean duration of DM in patients with early-onset DM with PaC was longer than that in the late-onset patients (26 vs. 9 years;
P
< 0.01). A family history of DM (odds ratio OR 3.60) and use of insulin (OR 3.52) were significant risk factors in patients with early-onset DM, while the onset age of DM (OR 1.12) and multiple diabetic patients in the family (OR 6.13) were risk factors in those with late-onset DM. Body weight loss and exacerbation of DM were seen 12 months prior to PaC diagnosis in both groups.
Conclusions
Our study revealed specific risk factors for and similar early signs of PaC in early-onset and late-onset DM. Thus, we could develop a screening strategy, combining these risk factors specific for DM-onset age with early signs of disease.
Abstract The third-line treatment regimen for Helicobacter pylori after failure of clarithromycin- and metronidazole-based therapies is not yet established. Sitafloxacin (STX) is a quinolone that ...possesses potent in vitro activity against H. pylori. In this study, the susceptibility of H. pylori isolates to STX was examined and the efficacy of STX-based triple therapy as a third-line regimen was evaluated. STX showed minimum inhibitory concentrations (MICs) of ≤1 μg/mL against all 100 H. pylori isolates, and the MIC90 (MIC for 90% of the organisms) of STX was 5 log2 dilutions lower than that of levofloxacin (LVX). The MIC50 (MIC for 50% of the organisms) of STX against gyrA mutants was 0.12 μg/mL and was significantly lower than that of LVX (8 μg/mL). The activity of STX at pH 5.5 was significantly less than that at pH 7.0. In the clinical trial, 28 patients with two eradication failures were treated with STX-based triple therapy rabeprazole 10 mg twice daily (b.i.d.), amoxicillin 750 mg b.i.d. and STX 100 mg b.i.d. for 7 days. The eradication rate was 75% using intention-to-treat analysis and 80% using per-protocol analysis. Two gyrA mutant strains were eradicated. Amongst participants, a low pepsinogen I/II ratio was associated with successful eradication. These results suggest that STX could be active against most clinical H. pylori isolates and that STX-based triple therapy is a promising and safe third-line therapy.
Helicobacter pylori infection is the most important risk factor for gastric cancer, for which eradication therapy is commonly performed. However, gastric cancer is sometimes discovered after ...successful eradication of H. pylori. Much evidence indicates that diabetes mellitus (DM) is a risk factor for gastric cancer. The incidence and characteristics of gastric cancer diagnosed after H. pylori eradication in DM patients remain to be determined.
We followed the clinical course of patients who underwent H. pylori eradication therapy at our institution. Endoscopy was performed before and after eradication. We compared the incidence and clinical characteristics of gastric cancer arising in DM and non-DM patients.
In total, 965 patients who underwent successful eradication (518 DM and 447 non-DM patients) were followed-up for an average of 4.5 years. During the follow-up period, 21 gastric cancers were diagnosed (12 in DM patients and 9 in non-DM patients). The incidence of gastric cancer after eradication was not significantly different between DM and non-DM patients (0.485 and 0.482 %/year, respectively). There was no significant difference in the pathology, diameter, depth, location, or treatment of gastric cancer between patients with and without DM.
The incidence and characteristics of gastric cancer occurring after H. pylori eradication were comparable between DM and non-DM patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
H. pylori eradication therapy has been widely performed. In addition, the number of patients with type 2 diabetes is increasing worldwide. The aim of this study was to understand the influence of H. ...pylori eradication therapy on the management of type 2 diabetes.
A total of 174 patients with type 2 diabetes who did not have an active peptic ulcer or serious complications and were cured successfully of their H. pylori infection at our institute were included in this study. The time course of mean glycosylated hemoglobin (HbA1c) values and body mass index (BMI) during the year before and after H. pylori eradication were assessed by a paired Student's t-test.
No significant changes in mean HbA1c values were observed during the year before or after eradication. However, the mean BMI, which did not change during the year before eradication, increased significantly at 6 months (23.1±2.6kg/m2, p<0.05) and 12 months (23.1±2.7kg/m2, p<0.05) after eradication as compared with the time point of eradication (22.9±2.6kg/m2).
H. pylori eradication significantly increased BMI but not HbA1c in patients with type 2 diabetes, despite diabetes treatment.
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