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Background Barrier function is essential for the maintenance of normal intestinal function. Dysregulation of the intestinal barrier underlies a wide range of disorders. Aim Previously, we found that sodium butyrate (NaB) decreased the molecular permeability of intestinal barrier in vivo model, but the mechanism by which NaB facilitated the tightness of tight junctions (TJs) in small intestinal epithelium needed further studies. Methods In vitro culture of the cdx2-IEC monolayer was used to mimic barrier function. The TJs were assessed by transepithelial electrical resistance (TEER) and paracellular flux of fluorescein isothiocyanate-conjugated dextran 40,000 (FD-40), Western blot, Q-RT-PCR, and immunofluorescence. Promoter and chromatin immunoprecipitation (ChIP) assays were also done to analyze the Claudin-1 gene. Results NaB decreased FD-40 flux, increased TEER and TJ protein Claudin-1 expression, induced ZO-1 and Occludin redistribution in cellular membrane, and reversed the damage effect after calcium (Ca 2+ ) switch assay. Silencing Claudin-1 prevented protective function of NaB from enhancing intestinal barrier integrity. Further studies demonstrated that NaB increased Claudin-1 transcription by facilitating the interaction between transcription factor SP1 and a specific motif within the promoter region of Claudin-1. This SP1 binding motif was located upstream of the coding region (−138 to −76 bp) and indispensable for the transcription of Claudin-1 following NaB treatment. ChIP assay confirmed the association between SP1 and Claudin-1 promoter, and the elimination of the SP1 binding site by point mutation resulted in a significant loss of Claudin-1 transcription after NaB dealing. Conclusions NaB enhanced intestinal barrier function through increasing Claudin-1 transcription via facilitating the association between SP1 and Claudin-1 promoter.

Secreted protein acidic and rich in cysteine (SPARC) is a glycoprotein that functions to inhibit angiogenesis, proliferation, and invasion in different types of cancer. The ability of SPARC to modulate neovascularisation is believed to be mediated in part by its ability to modulate the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). In this study, we aimed to determine the effect of SPARC expression in gastric cancer cells on proliferation and angiogenesis in vitro and in vivo. We evaluated expression of SPARC in seven human gastric cancer cell lines. Then we established a stably transfected SPARC overexpressed cell line (BGC-SP) and a stably transfected SPARC knock-down cell line (HGC-sh). The effect of SPARC overexpression and SPARC silencing was studied by examining capillary formation of HUVECs in vitro and a dorsal skin-fold chamber model in vivo. Quantitative real-time PCR and western blotting were performed to detect if the expressions of VEGF and MMP-7 were modulated by SPARC expression. To further determine the effect of SPARC expression on angiogenesis in vivo, xenograft models were established and microvessel density (MVD) of different clones were detected by immunohistochemistry. Endogenous SPARC overexpression inhibited the expression of VEGF and MMP-7, as well as the angiogenesis induced by BGC-SP cells. Correspondingly, SPARC silencing increased the expression of VEGF and MMP-7, as well as the angiogenesis induced by HGC-sh cells. Elevated angiogenesis induced by SPARC silencing in HGC-sh cells was decreased when VEGF was neutralised by antibodies, and MMP-7 was knocked down in vitro. SPARC suppresses angiogenesis of gastric cancer by down-regulating the expression of VEGF and MMP-7.

Introduction The prognosis for patients with carcinoma of the ampulla of Vater is improved relative to other periampullary neoplasms. Identification of independent prognostic factors in ampullary carcinomas has been limited by the small number of tumors resected. The aim of the present study was to determine the clinicopathologic factors that influence long‐term survival in patients with resected ampullary carcinoma. Methods Clinicopathologic data were retrospectively reviewed for patients with ampullary carcinomas radically resected between March 1987 and September 2002. The correlation between clinicopathologic variables and survival of patients after resection was examined by the Kaplan‐Meier method, the log‐rank test, and Cox proportional hazards regression. Ampullary carcinomas were radically resected in 127 patients either by pancreaticoduodenectomy (n = 124) or local resection (n = 3). Results Hospital mortality was 9.7%. The overall actuarial survival rates (including hospital deaths) at 1, 3, 5, and 10 years were 76.2%, 46.8%, 43.3%, and 35.7%, respectively. Factors that significantly influenced survival were lymph node status (P < 0.001), depth of tumor infiltration (P = 0.029), and TNM stage (P < 0.001) on univariate analysis. On multivariate analysis, both depth of infiltration and lymph node status were the independent determinants of survival after resection (P = 0.003, P = 0.005, respectively). Conclusions Carcinoma of the ampulla of Vater has a higher resectability rate and a much better survival rate than pancreatic cancer. Pancreaticoduodenectomy is the treatment of choice for this tumor. Long‐term survival was independently influenced by the depth of tumor infiltration and lymph node metastasis.

Purpose Increased expression of tissue factor (TF) is associated with tumor invasion and metastasis in human colorectal cancer. We have previously observed that TF/FVIIa upregulates matrix metalloproteinase-7 (MMP-7) expression at the transcriptional level in colon cancer cells. MMP-7 overexpression is believed to play an important role in tumor invasion and metastasis. The aim of this study is to elucidate the molecular mechanisms by which TF/FVIIa induced MMP-7 expression and cell invasion in vitro. Methods Reverse transcription polymerase chain reaction, Western blot, luciferase assay, and chromatin immunoprecipitation (ChIP) were used to determine the potential mechanism and signaling pathways by which TF/FVIIa induced MMP-7 expression and cell invasion in LoVo cells. Small interfering RNA (siRNA) and cell invasion assay was used to examine whether blocking c-Fos expression could abolish FVIIa-mediated upregulation of MMP-7 and cell invasion in vitro. Results The results showed that FVIIa induced the upregulation of MMP-7 both at the mRNA and protein levels in a time- and dose-dependent manner and increased the invasive behavior of LoVo cells. FVIIa enhanced the promoter activity of MMP-7, and the activator protein-1 (AP-1) binding site was responsible for the activation. Site mutation of the AP-1 binding site in the promoter almost completely abolished FVIIa-mediated response. Furthermore, ChIP assay confirmed that FVIIa promoted the direct binding of c-Fos with the MMP-7 promoter in vivo. FVIIa also induced the expression and nuclear accumulation of the AP-1 subunit c-Fos. siRNA-mediated knockdown of c-Fos eliminated FVIIa-stimulated MMP-7 expression and cell migration in vitro. In addition, selective mitogen-activated protein kinase (MAPK) kinase (MEK1/2) inhibitor (PD98059) and p38 MAPK inhibitor SB203580 suppressed MMP-7 upregulation induced by FVIIa. Conclusions Our data suggest that a novel TF/FVIIa/MAPK/c-Fos/MMP-7 axis plays an important role in modulating the invasion of colon cancer cells and blockage of this pathway holds promise to treat colon cancer metastasis.

Prognostic factors influencing long-term survival after radical resection for distal bile duct cancer have not been well established because of the rarity of this malignancy. The goal of this study was to identify main prognostic factors in patients undergoing pancreatoduodenectomy for distal bile duct carcinoma. A retrospective study consisting of 122 patients with distal bile duct cancer who underwent pancreatoduodenectomy in three major university hospitals was performed to identify the main prognostic factors. Major surgical complications occurred in 40 patients (32.8%), of whom eight died (6.6%) in the hospital. Overall actuarial survival (excluding hospital deaths) at 1-, 3-, and 5-year follow-up was 82.9, 49.4, and 32.7 per cent, respectively, with a median survival of 36 months. Univariate analysis showed that papillary tumor ( P = 0.045), negative surgical margin (R0 resection, P = 0.005), earlier pT ( P = 0.005), pTNM stage ( P < 0.001), and absence of lymph node involvement ( P < 0.0001) were significant predictors of survival. On multivariate analysis, only lymph node metastasis was shown to be an independent prognostic factor of survival ( P = 0.036). Lymph node involvement was the most important survival predictor after a Whipple resection in patients with distal cholangiocarcinoma.

Secreted protein acidic and rich in cysteine ( SPARC ) gene has been shown to be epigenetically silenced in several cancers. We investigated the loss of expression and promoter methylation of this tumor suppressor gene in gastric cancers and correlated the data with clinicopathological features. We observed the loss of SPARC mRNA and SPARC protein expression in 7 of 10 (70%) gastric cancer cell lines. Upon treatment of expression-negative cell lines with a demethylating agent, expression of mRNA and protein was restored in all cells. Methylation rate of SPARC gene was 80% in ten gastric cancer cell lines and 74% (163 of 220) in primary tumors, while it was 5% in normal gastric mucosa (n = 40). In intestinal gastric cancer, SPARC methylation correlated with a negative prognosis (P < 0.001; relative risk 2.754, 95% confidence interval 1.780–4.261). Immunostaining revealed that SPARC protein was overexpressed in stromal fibroblasts adjacent to neoplastic epithelium but rarely expressed in the primary gastric cancer cells. These results implicate SPARC promoter methylation as an important factor in the tumorigenesis of gastric carcinomas and provide new insights into the potential use of SPARC as a novel biomarker and the potential clinical importance in human gastric cancers.

Background Paraneoplastic pemphigus (PNP) is an autoimmune-related acquired bullous disease. Delayed diagnosis and treatment of this clinically rare disease often result in poor prognosis. Methods Between January 1999 and December 2009, 22 patients with confirmed PNP who underwent surgical resection of underlying tumors were enrolled in this study. Clinicopathologic characteristics, treatment options, and perioperative and long-term results were analyzed. Results Among 22 patients, 2 patients died of severe infection several weeks after surgery. Postoperative major complications included pulmonary infections (n = 10) and septicemia (n = 4). Respiratory symptoms persisted in 13 patients. Tumors were completely resected in 20 patients. Two patients whose tumors were not completely resected died of relapse 2 and 32 months after surgery. Two patients with completely resected tumors died of respiratory failure 10 and 24 months after surgery, respectively. One patient whose pathological result was follicular dentritic cell sarcoma had a relapse recently. The remaining 15 patients have survived till now. Conclusions Early detection, prompt treatment, and complete resection of PNP can effectively decrease the mortality and speed up the recovery.

Background and aims The extracellular interactions of plasma clotting factor VIIa (FVIIa) with tissue factor (TF) on the cell surface trigger intracellular signaling events involved in multiple physiological processes. TF expression is related to the metastatic potential of tumor cells and is a significant risk factor in the development of hepatic metastases in patients with colorectal cancer. At present, it is unclear how the interaction between TF and FVIIa influences the development of metastasis in colon cancer. Materials and methods We used a stable LOVO cell line derived from colorectal adenocarcinoma for our model Western blot analysis, Northern blot analysis, polymerase chain reaction, and RNA inference (RNAi), and the Dual-Luciferase Reporter Assay System technology were utilized to determine if MMP7 can be up-regulated by the VIIa/TF complex. Results Northern blot analysis confirmed that the plasma clotting factor FVIIa/TF complex resulted in a marked increase in MMP7 expression in a time- and dose-dependent manner via the p38 pathway in vitro. The proximal promoter of the human MMP7 gene was cloned into a luciferase reporter construction (MMP7.luc1592). Upon treatment with FVIIa, reporter activity in LOVO cells was increased by 2.5-fold. TF RNAi almost completely abolished FVIIa-mediated MMP7.luc induction. Deletion constructs from MMP7.luc1592 further defined an active promoter region. Interpretation Taken together, these data provide evidence that expression of MMP7 in colon cancer may be regulated by FVIIa and TF at the transcriptional level. MMP7 may act as a downstream mediator of FVIIa/TF signal transduction to facilitate the development of metastasis in colon cancer.

Secreted protein acidic and rich in cysteine (SPARC) is a glycoprotein that functions to inhibit angiogenesis, proliferation, and invasion in different types of cancer. The ability of SPARC to modulate neovascularisation is believed to be mediated in part by its ability to modulate the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). In this study, we aimed to determine the effect of SPARC expression in gastric cancer cells on proliferation and angiogenesis in vitro and in vivo. We evaluated expression of SPARC in seven human gastric cancer cell lines. Then we established a stably transfected SPARC overexpressed cell line (BGC-SP) and a stably transfected SPARC knock-down cell line (HGC-sh). The effect of SPARC overexpression and SPARC silencing was studied by examining capillary formation of HUVECs in vitro and a dorsal skin-fold chamber model in vivo. Quantitative real-time PCR and western blotting were performed to detect if the expressions of VEGF and MMP-7 were modulated by SPARC expression. To further determine the effect of SPARC expression on angiogenesis in vivo, xenograft models were established and microvessel density (MVD) of different clones were detected by immunohistochemistry. Endogenous SPARC overexpression inhibited the expression of VEGF and MMP-7, as well as the angiogenesis induced by BGC-SP cells. Correspondingly, SPARC silencing increased the expression of VEGF and MMP-7, as well as the angiogenesis induced by HGC-sh cells. Elevated angiogenesis induced by SPARC silencing in HGC-sh cells was decreased when VEGF was neutralised by antibodies, and MMP-7 was knocked down in vitro. SPARC suppresses angiogenesis of gastric cancer by down-regulating the expression of VEGF and MMP-7.