[Experimental study of the function of nuclear factor-κB-dependent epithelial to mesenchymal transition in pancreatic cancer cells under hypoxic conditions].

OBJECTIVE: To investigate the function of nuclear factor (NF)-κB in the epithelial to mesenchymal transition induced by hypoxia in pancreatic cancer cells. METHODS: For cultured pancreatic cancer cells (BxPC-3 and Panc-1) under hypoxic and normoxic conditions, the differences in the morphology were observed by optical microscope. The expression of markers of epithelial and mesenchymal phenotypes, E-cadherin, vimentin and N-cadherin, were determined by Western blot. NF-κB P65 activity was measured by electrophoretic mobility shift assay. Invasion and gemcitabine resistance of pancreatic cancer cells were evaluated in matrigel invasion assay and cell counting kit-8 assay. Both molecular and pharmacologic means of inhibiting NF-κB P65 were used in these hypoxic cells and then the above resulting phenotypes were compared with those of the control-treated cells. RESULTS: After cultured pancreatic cancer cells under hypoxic conditions for 48 h, normoxic cells exhibited a polygonal shape and formed tight clusters of cells, whereas hypoxic cells took on an elongated, fibroblastoid morphology associated with a more highly invasive character and resistance to gemcitabine; hypoxic cells exhibited an suppression of E-cadherin and increase in vimentin and N-cadherin expression. NF-κB P65 activity was elevated in hypoxic cells. On the contrary, on molecular or pharmacologic inhibition of NF-κB P65, hypoxic cells regained expression of E-cadherin, lost expression of N-cadherin, and reversed their highly invasive and drug resistant phenotype. CONCLUSIONS: Pancreatic cancer cells underwent epithelial to mesenchymal transition exposed to hypoxia, exhibited highly invasive and drug resistant phenotype. Inhibition of NF-κB P65 under hypoxic conditions, pancreatic cancer cells regained expression of E-cadherin, lost expression of N-cadherin, and reversed their highly invasive and drug resistant phenotype.

[Experience of the surgical comprehensive treatment on severe acute pancreatitis].

OBJECTIVE: To summary the experience of the surgical comprehensive treatment of severe acute pancreatitis (SAP). METHODS: From July 1999 to December 2009, a total of 506 patients suffered SAP were admitted with a mean APACHE II score 12.8 ± 4.6. There were 270 male and 236 female, aged from 16 to 89 years, mean age 43 years. SAP patients were treated by the SAP treatment team which consisted of pancreatic specialized and multidisciplinary doctors. Two hundreds and thirty-four cases (46.2%) received non-operative treatment and 272 cases (53.8%) received surgical intervention. RESULTS: In 506 cases, 445 patients were cured and 52 patients died (31 died in early stage, 21 died in later stage), 9 cases discharged automatically. The overall incidence of complication, overall mortality and overall curative rate were 29.4% (149/506), 10.3% (52/506) and 87.9% (445/506), respectively. The incidences of complication in non-operative group and in surgical intervention group were 27.8% (65/234) and 30.9% (84/272), respectively (P > 0.05). The mortality in non-operative group and in surgical intervention group were 9.4% (22/234) and 11.0% (30/272), respectively (P > 0.05). The curative rates in non-operative group and in surgical intervention group were 90.6% (212/234) and 85.7% (233/272), respectively (P > 0.05). CONCLUSIONS: Patients should be treated in ICU in the early phase of the disease when APACHE II score > 10. Pancreatic specialized and multidisciplinary team treatment, appropriate choice of timing, indication and procedure of surgical intervention and details of drainage are vital to the prognosis of SAP.

Protective Effects of Hydrogen Gas on Experimental Acute Pancreatitis.

Acute pancreatitis (AP) is an inflammatory disease mediated by damage to acinar cells and pancreatic inflammation. In patients with AP, subsequent systemic inflammatory responses and multiple organs dysfunction commonly occur. Interactions between cytokines and oxidative stress greatly contribute to the amplification of uncontrolled inflammatory responses. Molecular hydrogen (H2) is a potent free radical scavenger that not only ameliorates oxidative stress but also lowers cytokine levels. The aim of the present study was to investigate the protective effects of H2 gas on AP both in vitro and in vivo. For the in vitro assessment, AR42J cells were treated with cerulein and then incubated in H2-rich or normal medium for 24 h, and for the in vivo experiment, AP was induced through a retrograde infusion of 5% sodium taurocholate into the pancreatobiliary duct (0.1 mL/100 g body weight). Wistar rats were treated with inhaled air or 2% H2 gas and sacrificed 12 h following the induction of pancreatitis. Specimens were collected and processed to measure the amylase and lipase activity levels; the myeloperoxidase activity and production levels; the cytokine mRNA expression levels; the 8-hydroxydeoxyguanosine, malondialdehyde, and glutathione levels; and the cell survival rate. Histological examinations and immunohistochemical analyses were then conducted. The results revealed significant reductions in inflammation and oxidative stress both in vitro and in vivo. Furthermore, the beneficial effects of H2 gas were associated with reductions in AR42J cell and pancreatic tissue damage. In conclusion, our results suggest that H2 gas is capable of ameliorating damage to the pancreas and AR42J cells and that H2 exerts protective effects both in vitro and in vivo on subjects with AP. Thus, the results obtained indicate that this gas may represent a novel therapy agent in the management of AP.

Dihydroartemisinin inhibits angiogenesis in pancreatic cancer by targeting the NF-κB pathway.

PURPOSE: Dihydroartemisinin (DHA) has recently shown antitumor activity in human pancreatic cancer cells. However, its effect on antiangiogenic activity in pancreatic cancer is unknown, and the mechanism is unclear. This study was aimed to investigate whether DHA would inhibit angiogenesis in human pancreatic cancer. METHODS: Cell viability and proliferation, tube formation of human umbilical vein endothelial cells (HUVECs), nuclear factor (NF)-κB DNA-binding activity, expressions of vascular endothelial growth factor (VEGF), interleukin (IL)-8, cyclooxygenase (COX)-2, and matrix metalloproteinase (MMP)-9 were examined in vitro. The effect of DHA on antiangiogenic activity in pancreatic cancer was also assessed using BxPC-3 xenografts subcutaneously established in BALB/c nude mice. RESULTS: DHA inhibited cell proliferation and tube formation of HUVECs in a time- and dose-dependent manner and also reduced cell viability in pancreatic cancer cells. DHA significantly inhibited NF-κB DNA-binding activity, so as to tremendously decrease the expression of NF-κB-targeted proangiogenic gene products: VEGF, IL-8, COX-2, and MMP-9 in vitro. In vivo studies, DHA remarkably reduced tumor volume, decreased microvessel density, and down-regulated the expression of NF-κB-related proangiogenic gene products. CONCLUSIONS: Inhibition of NF-κB activation is one of the mechanisms that DHA inhibits angiogenesis in human pancreatic cancer. We also suggest that DHA could be developed as a novel agent against pancreatic cancer.

Nuclear factor-κB-dependent epithelial to mesenchymal transition induced by HIF-1α activation in pancreatic cancer cells under hypoxic conditions.

BACKGROUND: Epithelial to mesenchymal transition (EMT) induced by hypoxia is one of the critical causes of treatment failure in different types of human cancers. NF-κB is closely involved in the progression of EMT. Compared with HIF-1α, the correlation between NF-κB and EMT during hypoxia has been less studied, and although the phenomenon was observed in the past, the molecular mechanisms involved remained unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α) promotes EMT in pancreatic cancer cells. On molecular or pharmacologic inhibition of NF-κB, hypoxic cells regained expression of E-cadherin, lost expression of N-cadherin, and attenuated their highly invasive and drug-resistant phenotype. Introducing a pcDNA3.0/HIF-1α into pancreatic cancer cells under normoxic conditions heightened NF-κB activity, phenocopying EMT effects produced by hypoxia. Conversely, inhibiting the heightened NF-κB activity in this setting attenuated the EMT phenotype. CONCLUSIONS/SIGNIFICANCE: These results suggest that hypoxia or overexpression of HIF-1α induces the EMT that is largely dependent on NF-κB in pancreatic cancer cells.