Ellagic acid induces apoptosis through inhibition of nuclear factor κB in pancreatic cancer cells

AIM： To determine the effect of ellagic acid on apoptosis and proliferation in pancreatic cancer cells and to determine the mechanism of the pro-survival effects of ellagic acid.METHODS： The effect of ellagic acid on apoptosis was assessed by measuring Phosphatidylserine externalization, caspase activity, mitochondrial membrane potential and DNA fragmentation; and proliferation by measuring DNA thymidine incorporation. Mitochondrial membrane potential was measured in permeabilized cells, and in isolated mitochondria. Nuclear factor κB （NF-κB） activity was measured by electromobility shift assay （EMSA）. RESULTS： We show that ellagic acid, a polyphenolic compound in fruits and berries, at concentrations 10 to 50 mmol/L stimulates apoptosis in human pancreatic adenocarcinoma cells. Further, ellagic acid decreases proliferation by up to 20-fold at 50 mmol/L. Ellagic acid stimulates the mitochondrial pathway of apoptosis associated with mitochondrial depolarization, cytochrome C release, and the downstream caspase activation. Ellagic acid does not directly affect mitochondria. Ellagic acid dose-dependently decreased NF-κB binding activity. Furthermore, inhibition of NF-κB activity using IkB wild type plasmid prevented the effect of ellagic acid on apoptosis. CONCLUSION： Our data indicate that ellagic acid stimulates apoptosis through inhibition of the prosurvival transcription factor NF-κB.

Current status of diagnosis and therapy for intraductal papillary neoplasm of the bile duct

Bile duct epithelial tumours showing papillary neoplasm in the bile duct lumen are present in the intrahepatic and extrahepatic bile ducts.Clinicopathological images of these tumours are distinctive and diverse,including histological images with a low to high grade dysplasia,infiltrating and noninfiltrating characteristics,excessive mucus production,and similarity to intraductal papillary mucinous neoplasm(IPMN)of the pancreas.The World Health Organization Classification of Tumours of the Digestive System in 2010 named these features,intraductal papillary neoplasm of the bile duct(IPNB),as precancerous lesion of biliary carcinoma.IPNB is currently classified into type 1 that is similar to IPMN,and type 2 that is not similar to IPMN.Many of IPNB spreads superficially,and diagnosis with cholangioscopy is considered mandatory to identify accurate localization and progression.Prognosis of IPNB is said to be better than normal bile duct cancer.