Upregulation of miR-194 contributes to tumor growth and progression in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of human cancer worldwide. In the present study, we investigated the diagnostic and biological significance of microRNA-194 (miR-194) in PDAC. miRNA expression profiling of human PDACs and adjacent normal pancreatic tissues identified a total of 16 genes including miR-194 with >1.15-fold expression changes (8 overexpressed and 8 underexpressed). Quantitative real-time polymerase chain reaction (PCR) revealed elevation of serum miR-194 levels were significantly greater in PDAC patients than in duodenal adenocarcinoma patients and healthy controls. Receiver operating characteristic analysis demonstrated that serum miR-194 had a sensitivity of 54.3% and a specificity of 57.5% for discriminating PDAC patients from healthy controls. Combined analysis of the 3 groups yielded a sensitivity of 84.0 and a specificity of 75.0% for the combined detection of miR-192 and miR-194 in the diagnosis of PDAC. Ectopic expression of miR-194 in PANC-1 pancreatic cancer cells enhanced cell proliferation, migration and colony formation, which was coupled with decreased expression of the tumor suppressor DACH1. miR-194 overexpression increased tumor growth and local invasion and suppressed the expression of DACH1 in an orthotopic pancreatic cancer mouse model. In conclusion, upregulation of miR-194 contributes to tumor growth and progression in PDAC, possibly through suppression of DACH1. However, serum miR-194 has a low capacity for detection of PDAC. Combined detection of serum miR-192 and miR-194 levels may serve as a sensitive diagnostic biomarker for PDAC.

Expression of fibroblast activation protein in human pancreatic adenocarcinoma and its clinicopathological significance.

AIM: To examine fibroblast activation protein (FAP) expression in pancreatic ductal adenocarcinoma (PDAC) and to analyze its relationship with the clinicopathology of PDAC. METHODS: FAP expression was examined in 134 PDAC specimens by immunohistochemistry, and in four pancreatic cancer cell lines (SW1990, Miapaca-2, AsPC-1 and BxPC-3) by Western blotting assay. We also analyzed the association between FAP expression in PDAC cells and the clinicopathology of PDAC patients. RESULTS: The results showed that the FAP was ex-pressed in both stromal fibroblast cells (98/134, 73.1%) and carcinoma cells (102/134, 76.1%). All 4 pancreatic cancer cell lines expressed FAP protein at different levels. Protein bands corresponding to the proteolytically active 170-kDa seprase dimer and its 88-kDa seprase subunit were identified. Higher FAP expression in carcinoma cells was associated with tumor size (P < 0.001), fibrotic focus (P = 0.003), perineural invasion (P = 0.009) and worse clinical outcome (P = 0.0085). CONCLUSION: FAP is highly expressed in carcinoma cells and fibroblasts in PDAC tissues, and its expression is associated with desmoplasia and worse prognosis.

Surviving cells after treatment with gemcitabine or 5-fluorouracil for the study of de novo resistance of pancreatic cancer.

One of the hallmarks of pancreatic cancer is its inherent insensitivity to chemotherapy. This study was undertaken to develop a cell model for the study of de novo resistance of pancreatic cancer. The surviving pancreatic cancer cells after a 3-day exposure to gemcitabine or 5-fluorouracil followed by another 7-day recovery were potentially drug-resistant. They had similar morphology and comparable growth and tumorigenic potentials to their untreated parental cells. Repeated subculture affected the cell-cycle profile and growth characteristics of the surviving cells. Our data suggest that surviving pancreatic cancer cells after drug treatment are a useful model for exploring intrinsic resistance.

Fluctuations in the rate of autopsy in China.

Autopsy has played a unique role in the progression of clinical medicine, medical education, epidemiology, and public health. However, the autopsy rate has been decreasing during the past several decades worldwide, and its necessity is frequently argued. Autopsy-based research in China, a country with the world's largest population, is very important for studying the spectrum and epidemiology of diseases as well as for discovering new diseases. This article summarizes the brief history of autopsy in China and analyzes the cause of its decline in recent decades by reviewing previously published papers, review articles, self-collected materials, and private correspondence. Since the first officially permitted autopsy in 1913, China witnessed the highest autopsy rate between 1950 and 1970, and since then the autopsy rate began to decline as it in other parts of the world. The main reasons for the reduction in autopsy rates in China include negligence by hospital administrators and relevant government authorities, unmotivated clinicians, helpless pathologists, unenforceable regulations and laws, and local cultures and customs.

[Hepatitis B virus X protein inhibits hepatoma cell growth in vitro through p14(ARF)-dependent and p14(ARF)-independent pathways].

OBJECTIVE: To explore the effects of hepatitis B virus X protein (HBx) on hepatoma cell growth through p14(ARF)-dependent and p14(ARF)-independent pathways. METHODS: HBx and p14(ARF) were transfected either separately or in combination into HepG2 cells containing wt-p53 but not expressing p14(ARF). The cells were divided into 4 groups, namely pcDNA3 (control), pcDNA3HBx, pcDNA3p14(ARF), and pcDNA3HBx + pcDNA3p14(ARF) groups. Flow cytometry was used to examine the apoptosis rates and cell cycle progression of HepG2 cells in different groups. The expression of p14(ARF), MDM2, p53, and p21(WAF1) proteins were investigated by detecting the activity of p21(WAF1) promoter-luciferase and using Western blotting. RESULTS: The apoptosis rates of HepG2 cells in pcDNA3HBx and pcDNA3p14(ARF) groups were significantly higher than that in the control group (14.11%, 13.72% vs 10.66%). Compared with the control group, pcDNA3HBx and pcDNA3p14(ARF) groups also showed significantly higher cell percentages arrested at G(0)/G(1) phase (63.62%, 61.75% vs 57.42%), luciferase activity of p21 promoter (1.25-/+0.05, 1.09-/+0.06 vs 0.77-/+0.03) and expressions of p53 and p21(WAF1). The cell apoptosis rate, percentage of cells in G(0)/G(1) phase and expression level of p14(ARF) were even higher in pcDNA3HBx+pcDNA3p14(ARF) group (18.61%, 66.74%, and 3.53-/+0.43, respectively) than in either p14(ARF) or HBx group. CONCLUSION: HBx induces p53 expression through p14(ARF)-dependent and independent pathways to activate p21(WAF1) promoter, leading to G(0)/G(1) arrest and apoptosis of HepG2 cells.