Format

Send to

Choose Destination
J Agric Food Chem. 2017 Aug 9;65(31):6625-6637. doi: 10.1021/acs.jafc.7b02296. Epub 2017 Jul 28.

NOX2-Mediated TFEB Activation and Vacuolization Regulate Lysosome-Associated Cell Death Induced by Gypenoside L, a Saponin Isolated from Gynostemma pentaphyllum.

Author information

1
Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China.
2
College of Life Science and Technology, Jinan University , Guangzhou 510632, China.
3
The First Affiliated Hospital of Kunming Medical University , Kunming 650032, China.

Abstract

Downregulation of apoptotic signal pathway and activation of protective autophagy mainly contribute to the chemoresistance of tumor cells. Therefore, exploring efficient chemotherapeutic agents or isolating novel natural products that can trigger nonapoptotic and nonautophagic cell death such as lysosome-associated death is emergently required. We have recently extracted a saponin, gypenoside L (Gyp-L), from Gynostemma pentaphyllum and showed that Gyp-L was able to induce nonapoptotic cell death of esophageal cancer cells associated with lysosome swelling. However, contributions of vacuolization and lysosome to cell death remain unclear. Herein, we reveal a critical role for NADPH oxidase NOX2-mediated vacuolization and transcription factor EB (TFEB) activation in lysosome-associated cell death. We found that Gyp-L initially induced the abnormal enlarged and alkalized vacuoles, which were derived from lipid rafts dependent endocytosis. Besides, NOX2 was activated to promote vacuolization and mTORC1-independent TFEB-mediated lysosome biogenesis. Finally, raising lysosome pH could enhance Gyp-L induced cell death. These findings suggest a protective role of NOX2-TFEB-mediated lysosome biogenesis in cancer drug resistance and the tight interaction between lipid rafts and vacuolization. In addition, Gyp-L can be utilized as an alternative option to overcome drug-resistance though inducing lysosome associated cell death.

KEYWORDS:

NOX2; TFEB; gypenoside L; lysosome biogenesis; vacuolization

PMID:
28697598
DOI:
10.1021/acs.jafc.7b02296
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center