Avarol induces apoptosis in pancreatic ductal adenocarcinoma cells by activating PERK-eIF2α-CHOP signaling

• Published in: Marine drugs 2015-04, Vol.13 (4), p.2376-2389
• Main Authors: Namba, Takushi, Kodama, Rika
• Format: Article
• Language: English
• Subjects: Animals; Antineoplastic Agents - adverse effects; Antineoplastic Agents - pharmacology; Apoptosis - drug effects; avarol; Biomarkers - metabolism; Carcinoma, Pancreatic Ductal - drug therapy; Carcinoma, Pancreatic Ductal - metabolism; Cell Line; Cell Line, Tumor; CHOP; Dysidea - chemistry; eIF-2 Kinase - chemistry; eIF-2 Kinase - metabolism; Endoplasmic Reticulum Stress - drug effects; ER stress; Eukaryotic Initiation Factor-2 - agonists; Eukaryotic Initiation Factor-2 - metabolism; Gene Expression Regulation, Neoplastic - drug effects; Heat-Shock Proteins - agonists; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Humans; Inhibitory Concentration 50; Marine; Neoplasm Proteins - agonists; Neoplasm Proteins - antagonists & inhibitors; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; pancreatic ductal adenocarcinomas; Pancreatic Neoplasms - drug therapy; Pancreatic Neoplasms - metabolism; RNA Interference; Sesquiterpenes - adverse effects; Sesquiterpenes - pharmacology; Signal Transduction - drug effects; Transcription Factor CHOP - agonists; Transcription Factor CHOP - antagonists & inhibitors; Transcription Factor CHOP - genetics; Transcription Factor CHOP - metabolism; Up-Regulation - drug effects
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/md13042376

Avarol is a sesquiterpenoid hydroquinone with potent cytotoxicity. Although resolving endoplasmic reticulum (ER) stress is essential for intracellular homeostasis, erratic or excessive ER stress can lead to apoptosis. Here, we reported that avarol selectively induces cell death in pancreatic ductal adenocarcinomas (PDAC), which are difficult to treat owing to the availability of few chemotherapeutic agents. Analyses of the molecular mechanisms of avarol-induced apoptosis indicated upregulation of ER stress marker BiP and ER stress-dependent apoptosis inducer CHOP in PDAC cells but not in normal cells, suggesting that avarol selectively induces ER stress responses. We also showed that avarol activated the PERK-eIF2α pathway but did not affect the IRE1 and ATF6 pathways. Moreover, CHOP downregulation was significantly suppressed by avarol-induced apoptosis. Thus, the PERK-eIF2α-CHOP signaling pathway may be a novel molecular mechanism of avarol-induced apoptosis. The present data indicate that avarol has potential as a chemotherapeutic agent for PDAC and induces apoptosis by activating the PERK-eIF2α pathway.