Exosome-encapsulated microRNA-4525, microRNA-451a and microRNA-21 in portal vein blood is a high-sensitive liquid biomarker for the selection of high-risk pancreatic ductal adenocarcinoma patients.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with poor prognosis. This is due to late diagnosis and lack of reliable prognostic biomarkers. In this study, we focused on exosomal microRNA (miRNA) in portal vein blood (PVB) as a potential biomarker to identify patients at high-risk for recurrence and poor postoperative outcome. METHODS: Exosomal miR-4525, miR-451a and miR-21 expressions were assessed using PVB and peripheral blood (PB) collected from 55 PDAC patients during curative pancreatectomy. Correlation between the miRNA expressions and clinical outcomes, and target genes expressions was investigated. RESULTS: Exosomal miR-4525, miR-451a and miR-21 levels were upregulated in PVB, which were higher than those in the PB. High expression of miR-4525, miR-451a and miR-21 in PVB was associated with recurrence with a higher sensitivity, specificity, and accuracy than that in PB. Cox regression analysis showed miR-4525, miR-451a and miR-21 levels in PVB were independent prognostic factors for overall survival and disease-free survival. There was a negative correlation between the expressions of miR-4525 and MEN1 mRNA, miR-451a and CAB39 mRNA, and t miR-21 and PDCD4 mRNA. CONCLUSIONS: miR-4525, miR-451a and miR-21 in PVB are potential biomarkers identifying patients at high-risk for recurrence and poor survival in resected PDAC patients.

Farnesoid X Receptor Activation Enhances Transforming Growth Factor ß-Induced Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma Cells.

Farnesoid X receptor (FXR) is a receptor for bile acids and plays an important role in the regulation of bile acid metabolism in the liver. Although FXR has been shown to affect hepatocarcinogenesis through both direct and indirect mechanisms, potential roles of FXR in epithelial­mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) remain unclear. We examined the effect of several FXR ligands on EMT-related morphological changes in HCC cell lines, such as HuH-7 and Hep3B cells. FXR agonists (chenodeoxycholic acid, GW4064, and obeticholic acid)­but not an antagonist (guggulsterone)—induced actin polymerization and expression of N-cadherin and phosphorylated focal adhesion kinase, although they were less effective than transforming growth factor ß (TGF-ß). FXR agonist treatment enhanced TGF-ß-induced EMT morphologic changes and FXR antagonist inhibited the effect of TGF-ß. Thus, FXR activation enhances EMT in HCC and FXR antagonists may be EMT-suppressing drug candidates.

Usefulness of exosome-encapsulated microRNA-451a as a minimally invasive biomarker for prediction of recurrence and prognosis in pancreatic ductal adenocarcinoma.

BACKGROUND: MicroRNAs (miRNAs) encapsulated in the exosomes of plasma is of interest as stable and minimally invasive biomarkers for recurrence and prognosis in cancer patients. The aim of this study was to clarify the predictive and prognostic value of plasma exosomal microRNA-451a (miR-451a) in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Microarray-based expression profiling of miRNAs derived from exosomes in the plasma of six PDAC patients with UICC stage II was employed to identify a biomarker to distinguish between patients with and without recurrence. For validation analysis, plasma exosome samples of other 50 PDAC patients were measured by TaqMan MicroRNA assays. RESULTS: In the miRNA microarray analyses, miR-451a showed the highest upregulation in the stage II patients who showed recurrence after surgery. In the relationship to pathological factors, exosomal miR-451a showed a significant association with tumor size and stage. The overall survival (OS) and disease-free survival rates (DFS) of the high exosomal miR-451a patients were significantly worse than those of the low miR-451a patients. In Cox proportional hazards model analysis, exsomal miR-451a showed significance to OS and DFS. CONCLUSIONS: Plasma exosomal miR-451a levels may be a useful minimally invasive biomarker for the prediction of recurrence and prognosis in PDAC patients.

Prognostic impact of type of preoperative biliary drainage in patients with distal cholangiocarcinoma.

BACKGROUND: Surgical results of patients with resected distal cholangiocarcinoma (DCC) were evaluated to elucidate prognostic impact of the type of preoperative biliary drainage (PBD). METHODS: Eighty-eight patients with resected DCC were stratified into two groups according to the type of PBD: the percutaneous transhepatic biliary drainage (PTBD) group (n = 25) and the endoscopic biliary drainage (EBD) group (n = 63). RESULTS: Overall 5-year survival rate of the patients in the PTBD group was poorer than in the EBD group (24% vs. 52%, P = 0.020). On univariate analysis, PTBD, pancreatic invasion, perineural invasion, and lymph node involvement were significant prognostic factors for poor overall survival. On multivariate analysis, PTBD was the only significantly independent prognostic factor for poor overall survival. The incidence of liver metastasis was significantly higher in the PTBD group than in the EBD group (32.0% vs. 13.3%, P = 0.034). CONCLUSIONS: PTBD should be avoided as much as possible in patients with DCC since the patients who underwent PTBD had poorer overall survival and higher incidence of liver metastasis than those who underwent EBD.

Biweekly gemcitabine plus S-1 for locally advanced and metastatic pancreatic cancer: a preliminary feasibility study.

BACKGROUND: Chemotherapy for unresectable pancreatic cancer should not only prolong survival but maintain quality of life, considering its limited life expectancy. To achieve these goals, biweekly gemcitabine plus S-1 was assessed in the clinical practice setting. METHODS: Fifty-two patients with either locally advanced or metastatic pancreatic cancer who received biweekly gemcitabine plus S-1 as a first-line anti-cancer treatment were included in this study. Treatment delivery, toxicity, response, and survival were reviewed to assess the feasibility and efficacy. RESULTS: The completion rate of treatment delivery was 95.1%, with relative dose intensity of 97.1% for gemcitabine and 97.3% for S-1. Overall, grade 3 or worse adverse events were rare, with hematologic toxicities occurring in 5.8%. The objective response rate was 30.8%, and more than a 50% reduction of CA19-9 was observed in 77.1%. Surgical conversion was completed with a margin-negative resection in four patients whose tumor had shrunk for at least 6 months. The median progression-free and overall survivals were 10.4 and 18.2 months, respectively. Reduction of CA19-9 was associated with longer survival. CONCLUSIONS: Biweekly gemcitabine plus S-1 may be a good alternative to current standard chemotherapies for unresectable pancreatic cancer with less toxicity and less treatment burden without losing efficacy.

Periventricular notch activation and asymmetric Ngn2 and Tbr2 expression in pair-generated neocortical daughter cells.

To understand the cellular and molecular mechanisms regulating cytogenesis within the neocortical ventricular zone, we examined at high resolution the spatiotemporal expression patterns of Ngn2 and Tbr2. Individually DiI-labeled daughter cells were tracked from their birth in slice cultures and immunostained for Ngn2 and Tbr2. Both proteins were initially absent from daughter cells during the first 2 h. Ngn2 expression was then initiated asymmetrically in one of the daughter cells, with a bias towards the apical cell, followed by a similar pattern of expression for Tbr2, which we found to be a direct target of Ngn2. How this asymmetric Ngn2 expression is achieved is unclear, but gamma-secretase inhibition at the birth of daughter cells resulted in premature Ngn2 expression, suggesting that Notch signaling in nascent daughter cells suppresses a Ngn2-Tbr2 cascade. Many of the nascent cells exhibited pin-like morphology with a short ventricular process, suggesting periventricular presentation of Notch ligands to these cells.

Design, synthesis, and evaluation of non-steroidal farnesoid X receptor (FXR) antagonist.

A series of substituted-isoxazole derivatives was prepared as candidate farnesoid X receptor (FXR) antagonists, based on our previously proposed ligand superfamily concept. Structure-activity relationship studies indicated that the shape and the structural bulkiness of the substituent at the 5-position of the isoxazole ring affected FXR-antagonistic activity. Compounds 15 g (5-substituent: 2-naphthyl) and 15 h (5-substituent: 4-biphenyl) were identified as potent antagonists with higher selectivity for FXR over progesterone receptor than the naturally occurring FXR antagonist GS. The 5-substituent is also a critical determinant of the characteristic corepressor recruitment profile of this class of FXR antagonists, though distinct mechanisms appear to be involved: 15 h stabilizes the corepressor-nuclear receptor interaction, while 15 g inhibits coactivator recruitment.

Diphenylmethane skeleton as a multi-template for nuclear receptor ligands: preparation of FXR and PPAR ligands.

Novel, potent farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor alpha (PPARalpha) agonists were obtained by using a diphenylmethane skeleton as a substitute for a steroid skeleton.