GATA6-AS1 suppresses epithelial-mesenchymal transition of pancreatic cancer under hypoxia through regulating SNAI1 mRNA stability.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a hypoxic microenvironment, a high rate of heterogeneity as well as a high likelihood of recurrence. Mounting evidence has affirmed that long non-coding RNAs (lncRNAs) participate in the carcinogenesis of PDAC cells. In this study, we revealed significantly decreased expression of GATA6-AS1 in PDAC based on the GEO dataset and our cohorts, and showed that low GATA6-AS1 expression was linked to unfavorable clinicopathologic characteristics as well as a poor prognosis. Gain- and loss-of-function studies demonstrated that GATA6-AS1 suppressed the proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) process of PDAC cells under hypoxia. In vivo data confirm the suppressive roles of GATA6-AS1/SNAI1 in tumor growth and lung metastasis of PDAC. Mechanistically, hypoxia-driven E26 transformation-specific sequence-1 (ETS1), as an upstream modulatory mechanism, was essential for the downregulation of GATA6-AS1 in PDAC cells. GATA6-AS1 inhibited the expression of fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) eraser, and repressed SNAI1 mRNA stability in an m6A-dependent manner. Our data suggested that GATA6-AS1 can inhibit PDAC cell proliferation, invasion, migration, EMT process and metastasis under hypoxia, and disrupting the GATA6-AS1/FTO/SNAI1 axis might be a viable therapeutic approach for refractory hypoxic pancreatic cancers.

Nicotine promotes tumor progression and epithelial-mesenchymal transition by regulating the miR-155-5p/NDFIP1 axis in pancreatic ductal adenocarcinoma.

BACKGROUND: Nicotine, the major component of cigarette smoke, has been reported to promote pancreatic ductal adenocarcinoma (PDAC) growth and invasion. Deregulation of microRNA (miRNA) expression is found in many cancers, including PDAC. The effects of nicotine on miRNAs change in PDAC progression remain unknown. METHODS: The effects of cigarette smoking/nicotine exposure on PDAC cell lines and tissues were evaluated. Quantitative real-time PCR and in situ hybridization assays were used to determine miR-155-5p expression in human PDAC tissue and cell lines upon cigarette smoking/nicotine exposure. Bioinformatics, loss-of-function experiments, luciferase reporter assay were performed to validate Nedd4 family interacting protein 1 (NDFIP1) as a direct target of miR-155-5p. The potentials of systemic miR-155-5p inhibitor-based therapy in overcoming nicotine exposure were evaluated in tumor xenograft model. RESULTS: Nicotine promoted PDAC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in a dose-response manner. MiR-155-5p was found to be highly expressed in PDAC cell lines and tissues upon cigarette smoking/nicotine exposure. Functional studies showed that miR-155-5p knockdown could override the enhancement of oncogenic activity due to nicotine exposure in vitro and in vivo by directly interacting with the 3' untranslated regions (UTRs) of NDFIP1. CONCLUSIONS: These data demonstrate that nicotine-regulated miR-155-5p/NDFIP1 promotes tumor progression and EMT of PDAC.

Role of the potassium chloride cotransporter isoform 2-mediated spinal chloride homeostasis in a rat model of visceral hypersensitivity.

Visceral hypersensitivity represents an important hallmark in the pathophysiology of irritable bowel syndrome (IBS), of which the mechanisms remain elusive. The present study was designed to examine whether cation-chloride cotransporter (CCC)-mediated chloride (Cl(-)) homeostasis of the spinal cord is involved in chronic stress-induced visceral hypersensitivity. Chronic visceral hypersensitivity was induced by exposing male Wistar rats to water avoidance stress (WAS). RT-PCR, Western blotting, and immunohistochemistry were used to assess the expression of CCCs in the spinal cord. Patch-clamp recordings were performed on adult spinal cord slices to evaluate Cl(-) homeostasis and Cl(-) extrusion capacity of lamina I neurons. Visceral sensitivity was estimated by measuring the abdominal withdrawal reflex in response to colorectal distension (CRD). After 10 days of WAS exposure, levels of both total protein and the oligomeric form of the K(+)-Cl(-) cotransporter isoform 2 (KCC2), but not Na(+)-K(+)-2Cl(-) transporter isoform 1 (NKCC1), were significantly decreased in the dorsal horn of the lumbosacral spinal cord. The downregulation of KCC2 resulted in a depolarizing shifted equilibrium potential of GABAergic inhibitory postsynaptic current and impaired Cl(-) extrusion capacity in lamina I neurons of the lumbosacral spinal cord from WAS rats. Acute noxious CRD disrupted spinal KCC2 expression and function 2 h after the final distention in sham rats, but not in WAS rats. Pharmacological blockade of KCC2 activity by intrathecal injection of a KCC2 inhibitor [(dihydroindenyl)oxy] alkanoic acid enhanced visceral nociceptive sensitivity in sham rats, but not in WAS rats. These results suggest that KCC2 downregulation-mediated impairment of spinal cord Cl(-) homeostasis may play an important role in chronic stress-induced visceral hypersensitivity.

Dietary fiber intake reduces risk for colorectal adenoma: a meta-analysis.

BACKGROUND & AIMS: Reports on the association between dietary fiber intake and risk of colorectal adenoma (CRA), the precursor of colorectal cancer, have been inconsistent. We conducted a meta-analysis of case-control and cohort studies to analyze this association. METHODS: We searched the MEDLINE and EMBASE databases to identify relevant studies published through July 2013. A random-effects model was used to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs) for associations between fiber intake and CRA risk. Heterogeneity among studies was assessed using the Cochran Q and I(2) statistics. RESULTS: Our meta-analysis included 20 studies involving 10,948 subjects with CRA. The SRRs of CRA for total dietary fiber were 0.72 (95% CI, 0.63-0.83) in a high- vs low-intake analysis and 0.91 (95% CI, 0.87-0.95) per 10-g/day increase in fiber intake in a dose-response model. Subgroup analyses indicated a significant inverse association between total fiber intake and CRA risk in case-control studies (SRR, 0.66; 95% CI, 0.56-0.77), but not in cohort studies (SRR, 0.92; 95% CI, 0.76-1.10). The SRRs of CRA were 0.84 for fruit fiber (95% CI, 0.76-0.94; n = 6 studies), 0.93 for vegetable fiber (95% CI, 0.84-1.04; n = 6 studies), and 0.76 for cereal fiber (95% CI, 0.62-0.92; n = 9 studies) in high- vs low-intake analyses. CONCLUSIONS: Our findings support the hypothesis that high dietary fiber intake is associated inversely with CRA risk. Further studies with prospective designs that use validated questionnaires and control for important confounders are warranted.

Body mass index increases risk for colorectal adenomas based on meta-analysis.

BACKGROUND & AIMS: There have been inconsistent results published about the relationship between excess body weight, expressed as increased body mass index (BMI), and risk of colorectal adenoma (CRA). We conducted a meta-analysis to explore this relationship. We focused on whether the relationship varied based on the sex of the study subjects, study design, features of the polyps, or potential confounders, including alcohol use, nonsteroidal anti-inflammatory drug use, smoking, and exercise. METHODS: We identified studies by performing a literature search of Medline, EMBASE, and ISI Web of Science through July 31, 2011, and by searching the reference lists of pertinent articles. We analyzed 36 independent studies, which included 29,860 incident cases of CRA. Summary relative risks with their 95% confidence intervals (CIs) were calculated with a random-effects model. Between-study heterogeneity was assessed using Cochran's Q statistic and I(2) analyses. RESULTS: Overall, a 5-unit increase in BMI (calculated as kg/m(2)) increased the risk for CRA (summary relative risk = 1.19; 95% CI: 1.13-1.26), although there was a high level of heterogeneity among studies (P(heterogeneity) < .001; I(2) = 76.8%). Subgroup analyses revealed that the increased risk of CRA in obese individuals was independent of race, geographic location, study design, sex, adenoma progression, and confounders. The association between increased BMI and risk for CRA was stronger for colon than rectal adenoma. CONCLUSIONS: Based on a meta-analysis, increased BMI increases the risk for colon but not rectal adenoma. Unlike colorectal cancer, there is no sex difference in the relationship between increased BMI and risk of CRA.

DJ-1 promotes invasion and metastasis of pancreatic cancer cells by activating SRC/ERK/uPA.

A major hallmark of pancreatic ductal adenocarcinoma (PDAC) is extensive local tumor invasion and early systemic dissemination. DJ-1 has been shown to prevent cell death via the Akt pathway, thereby playing an important role in cancer progression and Parkinson's disease development. Here, we investigated the role of DJ-1 in tumor invasion and metastasis of pancreatic cancer and showed that DJ-1 is upregulated in 68.5% of pancreatic cancer specimens, correlated with tumor stage and predictive of short overall survival. Knockdown of DJ-1 expression in two PDAC cell lines reduced cell migration and invasion potential in vitro and inhibited metastasis in vivo. Knockdown of DJ-1 led to cytoskeleton disruption and diminished urokinase plasminogen activator (uPA) activity and expression, without affecting plasminogen activator inhibitor-1 and uPA receptor (uPAR) expression. All these effects were reversed by restoration of DJ-1 expression. In determining the pathway through which DJ-1 regulated cell migration and invasion, DJ-1 was found not to regulate Akt phosphorylation. Rather, it promoted extracellular signal-regulated kinase (ERK) and SRC phosphorylation. Inhibition of the ERK pathway in PDAC mimicked the effects of DJ-1 on cell migration, invasion, actin cytoskeleton and uPA/uPAR system and abolished the effects on promoting PDAC cell invasion and migration. These data represent the first identification of an important function of DJ-1, which is to regulate the invasion and metastasis properties of PDAC through the ERK/uPA cascade.

Increased risk of hepatocellular carcinoma in patients with diabetes mellitus: a systematic review and meta-analysis of cohort studies.

In recent years, increasing evidence has suggested a strong association between diabetes mellitus (DM) and hepatocellular carcinoma (HCC). To provide a quantitative assessment of this association, we performed a systematic review and meta-analysis of cohort studies. We collected studies through a literature search of Medline from January 1, 1966 and EMBASE from January 1, 1974, through July 31, 2010. Summary relative risks (SRRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. A total of 25 cohort studies that met our inclusion and exclusion criteria were included in our analysis. Among these, 18 studies showed that DM was associated with an increased incidence of HCC (SRRs = 2.01, 95% CI: 1.61-2.51), compared with individuals without DM. There was a statistically significant heterogeneity among these studies (Q = 136.68, p < 0.001, I(2) = 87.6%). Analyses subgrouped by controlling confounders revealed that the increased incidence of HCC was independent of geographic location, alcohol consumption, history of cirrhosis, or infections with hepatitis B (HBV) or hepatitis C virus (HCV). In addition, DM was also positively associated with HCC mortality (SRR = 1.56; 95% CI: 1.30-1.87), with no significant evidence of heterogeneity among studies (Q = 1.16, p = 0.56, I(2) =0%). There were no significant publication bias (p = 0.79 for Egger's regression asymmetry test). These findings strongly support a positive association between DM and increased risk of HCC in both males and females.

Risk of esophageal cancer in diabetes mellitus: a meta-analysis of observational studies.

OBJECTIVE: Inconsistent findings from observational studies have prolonged the controversy over the effects of history of diabetes mellitus (DM) on the risk of esophageal cancer (EC). We conducted a meta-analysis of epidemiologic studies to evaluate the association of a history of DM with the risk of EC. METHODS: We identified studies by a literature search of MEDLINE (from 1 January 1966) and EMBASE (from 1 January 1974), through 28 Feburary 2011, and by searching the reference lists of pertinent articles. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were calculated with a random-effects model. All statistical tests were two-sided. RESULTS: A total of 17 studies (6 case-control studies and 11 cohort studies) fulfilled the inclusion and exclusion criteria. Compared with non-diabetic individuals, diabetic individuals had a modestly increased risk of EC (SRRs 1.30, 95% CI: 1.12-1.50), with significant heterogeneity among studies (p = 0.042). In stratified analysis, the SRRs of EC were 1.28 (1.10-1.49) for diabetic men and 1.07 (95% CI, 0.71-1.62) for diabetic women, respectively. In addition, DM was associated with an increased risk of esophageal adenocarcinoma (SRR 2.12, 95% CI 1.01-4.46). There was no significant publication bias (p = 0.127 for Begg's adjusted rank correlation test and p = 0.629 for Egger's regression test). CONCLUSION: These findings support the hypothesis that men with diabetes may have a modestly increased risk of EC, while diabetic women were not the case.

Low expression of IGFBP7 is associated with poor outcome of pancreatic ductal adenocarcinoma.

BACKGROUND: Insulin-like growth factor binding protein 7(IGFBP7) has been implicated as a potential tumor suppressor in various human cancers, although the role of IGFBP7 in pancreatic ductal adenocarcinoma (PDAC) is still unknown. We investigated the expression pattern and clinical significance of IGFBP7 in human PDAC. METHODS: IGFBP7 expression was evaluated by immunohistochemistry in 190 patients with PDAC who underwent surgical tumor resection. Expression of IGFBP7 was correlated with that of p53 and Ki-67, clinicopathologic features. We also evaluated overall survival (OS) according to expression of IGFBP7 by Kaplan-Meier and Cox regression analyses. RESULTS: IGFBP7 expression was significantly downregulated in pancreatic cancer tissues compared with adjacent normal pancreas (P < 0.001) and was inversely associated with Ki-67 expression (r = -0.284, P < 0.001). No significant relationships were found for clinicopathologic features, such as diameter of tumor, node status, grade, and stage. Importantly, low expression of IGFBP7 was associated with poor OS, and this was also significant in multivariate Cox regression analysis (hazard ratio [HR], 1.38; 95 % confidence interval [95 % CI], 1.00-1.91; P = 0.05). CONCLUSIONS: We demonstrate for the first time that IGFBP7 is downregulated in pancreatic cancer, and low expression of IGFBP7 is correlated with increased proliferation and poor postoperative survival. IGFBP7 may be a tumor suppressor in PDAC.

Clinical profiles and long-term outcomes of patients with pancreatic ductal adenocarcinoma and diabetes mellitus.

BACKGROUND: Diabetes mellitus (DM) is considered to be a possible risk factor and/or a manifestation of pancreatic ductal adenocarcinoma (PDAC). This study is aimed at analysing the potential association of diabetes mellitus with the development and pathogenic degrees of PDAC and post-surgical survival of Chinese Han PDAC patients. METHODS: A total of 1123 patients with PDAC were recruited and included 256 patients with diabetes mellitus within 2 years (new-onset) and 62 patients with diabetes mellitus ≥ 2 years (long-standing). Additional 466 patients with type 2 diabetes mellitus were included in this study. Their clinical characteristics and long-term outcomes were analysed. RESULTS: In comparison with patients with type 2 diabetes mellitus alone, PDAC patients with new-onset diabetes mellitus had an older onset age of diabetes mellitus and lower body mass index (BMI). Among PDAC cases, patients with new-onset diabetes mellitus were associated with neural invasion, poor tumour differentiation and shorter post-surgical survival. However, more than half of these patients became euglycemic after surgical resection of tumours. CONCLUSIONS: PDAC patients developed new-onset diabetes mellitus at an older age, and they had shorter post-surgical survival. The underlying mechanisms by which comorbid diabetes mellitus affect the clinical profiles and outcomes of PDAC patients deserve further researches.

Role of δ2 opioid receptor in cardioprotection against hypoxia-reoxygenation injury.

Several lines of in vivo evidence demonstrated that activation of δ-opioid receptors (ORs) with agonists mimics the cardioprotective effect of ischemic preconditioning. However, the subtypes of ORs involved and the molecular and cellular mechanisms are not entirely clear. To investigate the significance of the contribution by δ ORs to cardiomyocyte survival, we used an in vitro model of hypoxia/reoxygenation (H/R) in primary cultures of neonatal rat cardiomyocytes to study the role of different δ ORs in cardiomyocyte apoptosis and the relevant downstream signaling pathway. The results showed that apoptosis in neonatal cardiomyocytes induced by H/R was reversed by δ2 OR agonist, deltorphin E but not by δ1 OR agonist DPDPE; the deltorphin E-induced cytoprotection was totally abrogated by the MEK inhibitor PD98059 and overexpression of dominant interfering form of MEK1; in contrast, overexpression of constitutive active form of MEK1 exerted a similar protective effect as deltorphin E. These results suggest that δ2 OR, but not δ1 OR, plays a key role in preventing cardiomyocytes from apoptosis during H/R injury, which is mainly mediated by the MEK/ERK1/2 pathway.

Pancreatic cancer incidence and outcome in relation to ABO blood groups among Han Chinese patients: a case-control study.

The aim of the current study was to determine the association between ABO blood group and the risk and progression of pancreatic ductal adenocarcinoma (PDAC) in the Han Chinese ethnic group. During the period of 2000-2009, 1,431 patients with PDAC and 1,449 age- and sex-matched controls were recruited in two university-affiliated hospitals. An unconditional multivariable logistic regression analysis was used to estimate adjusted odds ratios (ORs). The relationship between patient ABO blood group and clinicopathologic features was also analyzed. Compared with subjects having blood group O, a modestly higher risk was observed among cases with blood group A or AB with adjusted ORs (95% confidence interval) of 1.368 (1.127-1.661) and 1.391 (1.053-1.838), respectively. The TNM stages of tumors in patients with non-O blood groups (A, B or AB) were more highly advanced than in patients with blood group O (p < 0.001). Among patients who underwent a potentially curative operation, the median survival time of patients with blood group O was significantly longer than that of patients with non-O blood groups (16.0 months vs. 11.0 months, p = 0.001, log-rank test). This study shows evidence of an association between blood group type and risk for development and progression of PDAC. These findings merit further confirmation in a large population-based prospective study in patients of the Han Chinese ethnic group.

Assessment of morbidity and mortality associated with EUS-guided FNA: a systematic review.

BACKGROUND: EUS-guided FNA (EUS-FNA) permits both morphologic and cytologic analysis of lesions within or adjacent to the GI tract. Although previous studies have evaluated the accuracy of EUS-FNA, little is known about the complications of EUS-FNA. Moreover, the frequency and severity of complications may vary from center to center and may be related to differences in individual experience. OBJECTIVE: To systematically review the morbidity and mortality associated with EUS-FNA. DESIGN: MEDLINE and EMBASE were searched to identify relevant English-language articles. MAIN OUTCOME MEASUREMENTS: EUS-FNA-specific morbidity and mortality rates. RESULTS: We identified 51 articles with a total of 10,941 patients who met our inclusion and exclusion criteria; the overall rate of EUS-FNA-specific morbidity was 0.98% (107/10,941). In the small proportion of patients with complications of any kind, the rates of pancreatitis (36/8246; 0.44%) and postprocedure pain (37/10,941; 0.34%) were 33.64% (36/107) and 34.58% (37/107), respectively. The mortality rate attributable to EUS-FNA-specific morbidity was 0.02% (2/10,941). Subgroup analysis showed that the morbidity rate was 2.44% in prospective studies compared with 0.35% in retrospective studies for pancreatic mass lesions (P=.000), whereas it was 2.33% versus 5.07% for pancreatic cysts (P=.036). LIMITATIONS: Few articles reported well-designed, prospective studies and few focused on overall complications after EUS-FNA. CONCLUSIONS: EUS-FNA-related morbidity and mortality rates are relatively low, and most associated events are mild to moderate in severity.

Combination of thiazolidinedione and hydralazine suppresses proliferation and induces apoptosis by PPARγ up-expression in MDA-MB-231 cells.

No proven targeted therapy is currently available for the treatment of triple-negative breast cancer (TNBC). Ligand activation of peroxisome-activated receptor (PPAR)γ induces antitumor effects in cancer but not obviously in TNBC. In TNBC cells, combined treatment with thiazolidinedione and demethylation drugs Hydralazine up-regulated protein and mRNA levels of PPARγ. Besides, the combination of two drugs promote antiproliferative and apoptotic effects in TNBC cells and decrease the proliferation index in the tumor xenografts. Taken together, our results suggest that multidrug regimens including a combination of Thiazolidinedione and Hydralazine may provide a therapeutic advantage in TNBC.

Diabetes mellitus and incidence and mortality of colorectal cancer: a systematic review and meta-analysis of cohort studies.

Increasing evidence suggests that a history of diabetes mellitus (DM) may be associated with an increased risk of colorectal cancer (CRC). To provide a quantitative assessment of the association between DM and risk of CRC, We evaluated the relation between DM and incidence and mortality of CRC in a systematic review of cohort studies. Full publications of cohort studies were identified in MEDLINE, EMBASE and Science Citation Index Expanded, through February 28, 2011. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were summarized using a random-effects model. Between-study heterogeneity was assessed using the Cochran's Q and I2 statistics. A total of 41 cohort studies (35 articles) were included in this systematic review. Combining 30 cohort studies which presented results on diabetes and CRC incidence, diabetes was associated with an increased incidence of CRC (SRRs 1.27, 95% CI: 1.21-1.34), with evident heterogeneity among studies (P=0.002, I2=48.4%). Subgroup analysis and meta-regression analysis by controlling the confounders showed that the increased incidence of CRC was independent of geographic locations, sex, family history of colorectal cancer, smoking, physical activity and body mass index. Diabetes was also positively associated with CRC mortality (SRR 1.20, 95% CI: 1.03-1.40), with evidence of heterogeneity between studies (P<0.001, I2=81.4%). Results from this systematic review support that compared to non-diabetic individuals, diabetic individuals have an increased risk of CRC.

Serum interleukin-33 levels in patients with gastric cancer.

BACKGROUND: Interleukin-33 (IL-33) is a novel member of the IL-1 family of cytokines, and it is closely related to IL-18, one of the best characterized members of the IL-1 family. It's been demonstrated that elevated levels of IL-18 are involved in a wide variety of tumors, especially in gastric cancer. AIMS: The purpose of this study was to determine the correlations between serum IL-33 levels and the clinicopathologic features in gastric cancer patients. METHODS: Serum samples were collected from 68 patients with gastric cancer and 57 controls. Serum IL-33 levels were measured by ELISA. Classical tumor markers of CEA and CA19-9 levels were routinely detected by chemiluminescence immunoassay. Western blot analysis was used to detect IL-33 expression in gastric cancer tissue samples and cell lines. The relationship between serum levels of IL-33 and clinical characteristics in patients was analyzed. RESULTS: IL-33 levels in the serum of gastric cancer patients were significantly elevated in comparison with that of healthy volunteers. Furthermore, higher serum levels of IL-33 in gastric cancer patients were found to correlate with several poor prognostic factors like depth of invasion, distant metastasis and advanced stage (stage III/IV). On the other hand, serum IL-33 levels did not correlate with CEA and CA19-9. The expression of IL-33 protein was upregulated in carcinoma tissues in comparison with matched normal tissues, and no statistically significant difference was found between the four gastric cancer cell lines and human gastric epithelial cell line GES-1. CONCLUSIONS: Serum IL-33 may be a useful biomarker for predicting the prognosis of gastric cancer.

Positive expression of L1-CAM is associated with perineural invasion and poor outcome in pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) frequently invades and migrates along neural tissue, which results in local tumor recurrences, distant metastases, and poor prognosis. We evaluated whether L1 cell adhesion molecule (L1-CAM) and glial cell line-derived neurotrophic factor (GDNF) expression in PDAC correlated with neural invasion and overall survival on a large cohort of previously untreated patients. METHODS: L1-CAM and GDNF were examined by immunohistochemistry in pancreatic cancer tissue samples of 94 cases with PDAC on a tissue microarray. The molecular findings were correlated with pain, clinicopathologic characteristics, and overall survival in these patients. RESULTS: L1-CAM and GDNF were overexpressed in pancreatic cancer tissues compared with the adjacent normal tissues of pancreas. Positive L1-CAM expression was associated with node involvement (P = 0.007), vascular invasion (P = 0.012), perineural invasion (P = 0.001), and higher degree of pain (P = 0.005). In univariate analysis, tissue expression of L1-CAM was associated with poor survival (hazard ratio, 2.508; 95% confidence interval, 1.551-4.053; P < 0.001), and this was also significant in multivariate analysis (hazard ratio, 2.046; 95% confidence interval, 1.200-3.488; P = 0.009). Positive staining of GDNF, neural invasion, and vascular invasion were all statistically significantly related to unfavorable prognosis. CONCLUSIONS: Enhanced expression of L1-CAM may contribute to the pain syndrome and perineural invasion and may correlate with poor overall survival in human pancreatic cancer.

A nicotine-induced positive feedback loop between HIF1A and YAP1 contributes to epithelial-to-mesenchymal transition in pancreatic ductal adenocarcinoma.

BACKGROUND: Nicotine, an active ingredient in tobacco, can promote epithelial-to-mesenchymal transition (EMT) processes that enhance the aggressiveness of a number of human cancers. In the present study, we investigated whether cigarette smoke/nicotine drives EMT in pancreatic ductal adenocarcinoma (PDAC). METHODS: Quantitative real-time PCR, western blot, immunohistochemistry, and immunofluorescence assays were used to evaluate Yes-associated protein 1 (YAP1) expression associated with cigarette smoking in human PDAC tissue samples and with nicotine exposure in PDAC cell lines. Bioinformatics, loss- and gain- of- function experiments, luciferase reporter assays, chromatin immunoprecipitation (ChIP), and murine tumor xenograft models were performed to examine the function of YAP1 in PDAC and to identify potential mechanisms of action. RESULTS: Exposure to smoking or nicotine promoted EMT and tumor growth in PDAC cells and in xenograft tumors. Functional studies revealed that YAP1 might drive nicotine-stimulated EMT and oncogenic activity in vitro and in vivo. In human PDAC tissues, upregulation of YAP1 was associated with "ever smoking" status and poor overall survival. In term of mechanism, hypoxia inducible factor (HIF)1A promoted YAP1 nuclear localization and YAP1 transactivation by directly binding to the hypoxia responsive elements of the YAP1 promoter upon nicotine treatment. Nicotine stimulated HIF1A and YAP1 expression by activating cholinergic receptor nicotinic alpha7 (CHRNA7). In addition, YAP1 increased and sustained the protein stability of HIF1A. CONCLUSIONS: These data demonstrate that YAP1 enhances nicotine-stimulated EMT and tumor progression of PDAC through a HIF1A/YAP1 positive feedback loop. Developing inhibitors that specifically target YAP1 may provide a novel therapeutic approach to suppress PDAC growth, especially in PDAC patients who have a history of smoking.

TRPV4 Overexpression Promotes Metastasis Through Epithelial-Mesenchymal Transition in Gastric Cancer and Correlates with Poor Prognosis.

PURPOSE: Transient receptor potential vanilloid 4 (TRPV4) has been reported to be involved in the progression of several human tumors. Nevertheless, clinical significance and molecular mechanism of TRPV4 in gastric cancer (GC) remain poorly defined. PATIENTS AND METHODS: Immunohistochemistry assays were used to investigate the correlation between the expression of TRPV4 and epithelial-mesenchymal transition (EMT) markers in human GC tissues. The correlations between TRPV4 expression and clinicopathological features and between TRPV4 expression and survival rates were also examined. TRPV4 knockdown was performed by using small interfering RNAs. In vitro, Cell Counting Kit-8 (CCK-8) assay, colony formation assay, and transwell assay were employed to further explore the biological functions of TRPV4, and Western blotting was used to evaluate the changes in the expression of TRPV4 protein and EMT-related proteins in HGC-27 and MGC-803 human GC cell lines. RESULTS: TRPV4 expression was upregulated in GC tissues and cell lines. TRPV4 overexpression was associated with greater depth of tumor invasion, lymph node metastasis, higher TNM stage, poor overall survival, and worse disease-free survival. TRPV4 expression was inversely correlated with E-cadherin expression and positively correlated with vimentin expression. In vitro, knockdown of TRPV4 inhibited GC cell proliferation, colony formation, and invasion. Furthermore, the knockdown of TRPV4 modulated EMT by upregulating E-cadherin expression and downregulating the expression of N-cadherin and vimentin. In addition, the EMT-related transcription factor Snail was downregulated, whereas the expression levels of other transcription factors such as Slug and Twist did not change. CONCLUSION: TRPV4 was upregulated in human GC and the overexpression of TRPV4 could promote GC progression, partially through Snail-mediated EMT.

Circulating levels of periostin may help identify patients with more aggressive colorectal cancer.

Elevated levels of periostin have been implicated as playing important roles in tumor invasion and metastasis in various tissues. Thus, we determined whether serum periostin levels were associated with progression and poor prognosis in colorectal cancer (CRC) patients. We measured serum periostin levels by ELISA in 67 CRC patients and 120 controls. We also evaluated periostin expression in human CRC specimens (n=15) using immunohistochemistry, and measured expression of periostin mRNA in 7 CRC tissue samples, matched normal tissues and in 4 colon cancer cell lines by RT-PCR. We analyzed the relationship between serum levels of periostin and other clinicopathologic characteristics in patients with CRC. The serum levels of periostin in CRC patients (40.9+/-15.4 ng/ml) were significantly elevated compared to that in healthy volunteers (21.0+/-7.3 ng/ml, P<0.0001) and benign colorectal polyps or adenomas (22.4+/-8.5 ng/ml, P<0.0001). Higher preoperative serum levels of periostin in CRC were found to correlate with distant metastasis (P=0.003), advanced-stage disease (stage III/IV, P<0.0001) and poor prognosis. Preoperative serum periostin levels of 15 cases were significantly higher than matched postoperative levels (47.2+/-13.5 ng/ml vs. 31.3+/-11.0 ng/ml, P=0.008). Twelve of 15 patients (80%) had positive immunohistochemical periostin staining in CRC samples. Interestingly, periostin mRNA was highly upregulated in CRCs in comparison with matched normal tissues, and no expression of periostin mRNA was detected in 4 colon cancer cell lines. Serum levels of periostin detected by ELISA may be of clinical value in identifying patients who may be at high risk for aggression and metastasis of CRC. Periostin may be produced by the stromal cells surrounding the tumor, but not by the CRC cells themselves.