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Background: Pancreatic cancer is obstinate and resistant to gemcitabine, a standard chemotherapeutic agent for the disease. We previously showed a therapeutic effect of glycogen synthase kinase-3β (GSK3β) inhibition against gastrointestinal cancer and glioblastoma. Here, we investigated the effect of GSK3β inhibition on pancreatic cancer cell sensitivity to gemcitabine and the underlying molecular mechanism.Methods: Expression, phosphorylation, and activity of GSK3β in pancreatic cancer cells (PANC-1) were examined by Western immunoblotting and in vitro kinase assay. The combined effect of gemcitabine and a GSK3β inhibitor (AR-A014418) against PANC-1 cells was examined by isobologram and PANC-1 xenografts in mice. Changes in gene expression in PANC-1 cells following GSK3β inhibition were studied by cDNA microarray and reverse transcription (RT)-PCR.Results: PANC-1 cells showed increased GSK3β expression, phosphorylation at tyrosine 216 (active form), and activity compared with non-neoplastic HEK293 cells. Administration of AR-A014418 at pharmacological doses attenuated proliferation of PANC-1 cells and xenografts, and significantly sensitized them to gemcitabine. Isobologram analysis determined that the combined effect was synergistic. DNA microarray analysis detected GSK3β inhibition-associated changes in gene expression in gemcitabine-treated PANC-1 cells. Among these changes, RT-PCR and Western blotting showed that expression of tumor protein 53-induced nuclear protein 1, a gene regulating cell death and DNA repair, was increased by gemcitabine treatment and substantially decreased by GSK3β inhibition.Conclusions: The results indicate that GSK3β inhibition sensitizes pancreatic cancer cells to gemcitabine with altered expression of genes involved in DNA repair. This study provides insight into the molecular mechanism of gemcitabine resistance and thus a new strategy for pancreatic cancer chemotherapy. [ABSTRACT FROM AUTHOR]

The p8 gene is barely expressed in the normal pancreas, but is overexpressed in acute pancreatitis. To elucidate the dynamic expression of p8 mRNA and its significance in the course of chronic pancreatitis, we investigated the p8 expression in spontaneous chronic pancreatitis in the WBN/Kob rat as well as in humans and arginine-treated rat pancreatic acinar AR4-2J cells. p8 mRNA was significantly increased at 12 weeks when chronic pancreatitis first appeared in the WBN/Kob rats. p8 was immunolocalized in the acinar cell nuclei. Acinar cell apoptosis was significantly increased at 12 and 20 weeks in the WBN/Kob rats. In AR4-2J cells, p8 mRNA was significantly induced at 4 hr after arginine addition. Apoptosis of AR4-2J cells was not increased during the strong expression of p8 mRNA. These results suggest that p8 is induced in the acinar cells during chronic pancreatitis as the self-defence mechanism against proapoptotic insults. [ABSTRACT FROM AUTHOR]

The Fas/Fas ligand (FasL) system is suggested to be correlated to the onset of inflammation and apoptosis in various diseases. However, whether Fas and FasL are expressed in chronic pancreatitis is unknown. The aim of this study was to examine the expression of the Fas/FasL system and to analyze its correlation with apoptosis in a spontaneous chronic pancreatitis model (the WBN/Kob rat). Four-week-old male WBN/Kob rats were fed a special pellet diet (MB-3). Different groups of rats were killed every four weeks, and pancreata were histopathologically examined. Fas and FasL mRNAs in the pancreas were detected with a reverse transcription-polymerase chain reaction method. The cellular localization of Fas and FasL mRNA and protein was determined with in situ hybridization (ISH) and immunohistochemistry (IHC). Apoptosis was detected with a terminal deoxynucleotidyltransferase-mediated method. Fas and FasL mRNA were expressed when the pancreas was still pathologically normal, and showed a biphasic peak at 12 and 20 weeks. ISH and IHC confirmed that Fas and FasL are expressed in the cytoplasm of acinar cells, ductal cells, and lymphocytes. An apoptotic index in acinar cells correlated to the expression of Fas and FasL mRNAs. These results suggest that the expression of the Fas/FasL system is involved in acinar cell apoptosis and the onset and progression of chronic pancreatitis in the WBN/Kob rat. [ABSTRACT FROM AUTHOR]

Transforming growth factor-beta1 (TGF-beta1) is suggested to be a mediator of fibrosis in chronic pancreatitis, but the serial change of TGF-beta1 expression in the onset and progression of chronic pancreatitis is still unclear. We investigated the TGF-beta1 expression in the spontaneous chronic pancreatitis model. Four-week-old male WBN/Kob rats were fed with special pellet diet (MB-3) for 20 weeks. TGF-beta1 mRNA in the pancreas was detected by reverse transcription-polymerase chain reaction assay from four weeks, and its expression peaked at 12 weeks when the pancreatic fibrosis first appeared. The localizations of TGF-beta1 mRNA and protein were confirmed in the cytoplasm of pancreatic acinar and ductal cells by in situ hybridization and immunohistochemistry, respectively. Although fibronectin expression peaked at 12 weeks and correlated with that of TGF-beta1, its elevated expression tended to be prolonged. Pancreatic fibrosis peaked at 16 weeks after the peak of TGF-beta1 expression. These results suggest that TGF-beta1 expression may be a trigger of the fibrotic process of chronic pancreatitis in the WBN/Kob rat. [ABSTRACT FROM AUTHOR]

The serum levels of pancreatitis-associated protein (PAP) were measured in 196 patients with digestive diseases and 15 healthy subjects by an enzyme-linked immunosorbent assay. The serum PAP levels were significantly elevated in the patients with gastric, colorectal, biliary tract, hepatocellular, or pancreatic cancers compared with the healthy subjects. After curative resection of the tumor, serum PAP levels were significantly decreased. The serum PAP levels were not related to clinicopathological factors except for the tumor size of pancreatic cancer. There were some cases of PAP-positive and carcinoembryonic antigen (CEA) or carbohydrate antigen (CA) 19-9 -negative gastric and colorectal cancers. The serum PAP levels were also significantly elevated in the patients with acute pancreatitis compared with those in not only the healthy subjects but also the patients with chronic pancreatitis. The peak PAP levels were significantly correlated with the severity of acute pancreatitis and reflected the clinical healing of the disease. The peak of serum PAP was significantly delayed compared with those of other pancreatic enzymes. These results suggest that the increase of serum PAP levels in patients with gastrointestinal cancers reflects an ectopic expression of PAP in cancer cells and that increased serum levels of PAP in acute pancreatitis are correlated with the disease severity and are prolonged than those of other pancreatic markers. [ABSTRACT FROM AUTHOR]

p53 and Bcl-2 are two important factors related to apoptosis and tumorigenesis. In this study, a series of 52 cases of pancreatic carcinoma (PC) were investigated using an immunohistochemical assay to determine whether altered expression of Bcl-2 and p53 has an impact on the progression of this malignancy. Cytoplasmic immunoreactivity for Bcl-2 and nuclear staining of p53 was found in 12 (23.1%) and 32 (63.5%) cases of PC respectively. Furthermore, an inverse correlation between the expression of p53 and Bcl-2 existed in this series (P < 0.01). In a subgroup, the proportion of tumours showing that p53-positive and Bcl-2-negative staining was increased with increasing histological grade and clinical stage (P < 0.05), and moreover, the survival period of those patients whose tumour had this staining was shorter than those with other staining patterns of combined p53 and Bcl-2 (P < 0.05). Therefore, it is concluded that simultaneously aberrant expression of Bcl-2 and p53 may confer PC with more malignant clinicopathological characteristics. [ABSTRACT FROM AUTHOR]

We report a case of Cruveihier-Baumgarten syndrome associated with portal vein thrombosis that developed, slowly during a 2-year period after endoscopic variceal sclerotherapy. The thrombosis led to the disappearance of the venous hum and the dilated abdominal wall veins characteristic of this syndrome. A 73-year-old woman was hospitalized for treatment of esophageal varices in April 1988. Her spleen was markedly enlarged, and the histologic findings of her liver were not consistent with hepatic cirrhosis, but with idiopathic portal hypertension. A venous hum was audible in the upper abdomen. Superior mesenteric angiography revealed a porto-systemic shunt vessel under the abdominal wall, originating from the umbilical vein. She was injected four times with a sclerosant, and this brought about disappearance of the esophageal varices. Two years after the first admission, the venous hum was no longer audible, but there was a recurrence of the esophageal varices. More than 2 years later (4 years after the first admission), ultasonographic study, computed tomography, and angiography showed a large thrombus, which completely obstructed the portal vein at the origin of the umbilical vein, and the development of collateral vessels, seen as a "cavernous transformation." [ABSTRACT FROM AUTHOR]

An enzyme-linked immunosorbent assay, based on two monoclonal antibodies (Hreg1-1 and Hreg101-1) specific for pancreatic stone protein (PSP)/reg-protein, was developed to determine the concentration of this protein in serum from individuals with various diseases. The serum concentration of PSP/reg-protein was significantly higher in patients with various pancreatic diseases than in normal controls, and was also significantly higher in patients with acute pancreatitis or chronic relapsing pancreatitis than in patients with chronic pancreatitis. Furthermore, the serum PSP/reg-protein concentration was also significantly increased in liver cirrhosis, choledocholithiasis, and various cancers of the digestive system, and was extremely high in all patients tested with chronic renal failure. A significant correlation was apparent between the serum concentration of PSP/reg-protein and elastase-I in 68 patients with chronic pancreatitis or pancreatic cancer. Whereas only 7 of these patients showed a normal serum PSP/reg-protein concentration and a significantly increased elastase-I concentration, 15 of these patients showed a significantly increased serum PSP/reg-protein concentration and a normal serum elastase-I concentration. These results indicate that the serum PSP/reg-protein concentration may reflect pancreatic damage, especially in acute pancreatitis, and may be a sensitive a marker for such damage as elastase-1, although false positivity was apparent in renal failure and in some patients with hepatic dysfunction or digestive system malignancies. [ABSTRACT FROM AUTHOR]

The clinical significance of the measurement of c-erbB-2 oncogene product was evaluated. The subjects consisted of 404 patients, including 248 with cancer of the digestive organs and 128 with benign digestive diseases. Serum c-erbB-2 protein levels were measured by sandwich immunoenzyme assay. The positive rates of c-erbB-2 protein, at a cut-off value of 17.0 U/ml, were, for cancers: hepatocellular carcinoma 61.6%, biliary tract cancer 54.8%, pancreatic cancer 25.0%, esophageal cancer 33.3%, gastric cancer 16.9%, and colorectal cancer 5.0%. For benign digestive diseases, the rates were: liver cirrhosis 63.3%, chronic hepatitis 43.2%, acute hepatitis 42.9%, other liver diseases 42.8%, cholelithiasis 30.0%, and chronic pancreatitis 0%. Serum c-erbB-2 protein levels were significantly correlated with the markers of hepatic functional reserve, the indocyanine green retention rate and the hepaplastin test. These findings suggest that serum c-erbB-2 protein levels are greatly influenced by liver dysfunction and that their clinical usefulness as a serum tumor marker is questionable. [ABSTRACT FROM AUTHOR]