JNK-dependent Atg4 upregulation mediates asperphenamate derivative BBP-induced autophagy in MCF-7 cells.

Abstract

N-Benzoyl-O-(N'-(1-benzyloxycarbonyl-4-piperidiylcarbonyl)-D-phenylalanyl)-D-phenylalaninol (BBP), a novel synthesized asperphenamate derivative with the increased solubility, showed growth inhibitory effect on human breast carcinoma MCF-7 cells in a time- and concentration-dependent manner. The growth inhibitory effect of BBP was associated with induction of autophagy, which was demonstrated by the development of acidic vesicular organelles, cleavage of LC3 and upregulation of Atg4 in BBP-treated MCF-7 cells. Since the application of Atg4 siRNA totally blocked the cleavage of LC3, we demonstrated a central role of Atg4 in BBP-induced autophagy. The further studies showed that BBP increased the levels of reactive oxygen species (ROS), and pretreatment with NAC effectively blocked the accumulation of ROS, autophagy and growth inhibition triggered by BBP. Moreover, BBP induced the activation of JNK, and JNK inhibitor SP600125 reversed autophagy, the increase of Atg4 levels, conversion of LC3 and growth inhibition induced by BBP. Knockdown of JNK by siRNA efficiently inhibited ROS production and autophagy, but antioxidant NAC failed to block JNK activation induced by BBP, indicating that JNK activation may be a upstream signaling of ROS and should be a core component in BBP-induced autophagic signaling pathway. These results suggest that BBP produces its growth inhibitory effect through induction of the autophagic cell death in MCF-7 cells, which is modulated by a JNK-dependent Atg4 upregulation involving ROS production.

• Authors: Yanchun Li, Qiyu Luo, Lei Yuan, Caixia Miao, Xiaoshuo Mu, Wei Xiao, Jianchun Li, Tiemin Sun, Enlong Ma
• Journal: Toxicology and applied pharmacology (Toxicol Appl Pharmacol) Vol. 263 Issue 1 Pg. 21-31 (Aug 15 2012) ISSN: 1096-0333 [Electronic] United States
• PMID: 22668848 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Elsevier Inc. All rights reserved.

Chemical References

• Antineoplastic Agents
• Autophagy-Related Proteins
• Benzamides
• N-benzoyl-O-(N'-(1-benzyloxycarbonyl-4-piperidiylcarbonyl)phenylalanyl)phenylalaninol
• Reactive Oxygen Species
• Phenylalanine
• JNK Mitogen-Activated Protein Kinases
• ATG4A protein, human
• Cysteine Endopeptidases

Topics

• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects)
• Autophagy (drug effects)
• Autophagy-Related Proteins
• Benzamides (pharmacology)
• Blotting, Western
• Breast Neoplasms (drug therapy)
• Carcinoma (drug therapy)
• Cell Cycle (drug effects)
• Cell Line, Tumor
• Cysteine Endopeptidases (physiology)
• Dose-Response Relationship, Drug
• Female
• HeLa Cells
• Humans
• JNK Mitogen-Activated Protein Kinases (physiology)
• Phenylalanine (analogs & derivatives, pharmacology)
• Reactive Oxygen Species (metabolism)
• Up-Regulation (drug effects)