Open Access
Etoposide induced cytotoxicity mediated by ROS and ERK in human kidney proximal tubule cells
Author(s) -
Hyeon-Jun Shin,
HyukKwon Kwon,
JaeHyeok Lee,
Muhammad Ayaz Anwar,
Sangdun Choi
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep34064
Subject(s) - cytotoxicity , mapk/erk pathway , dna damage , apoptosis , microbiology and biotechnology , reactive oxygen species , chemistry , biology , kinase , cancer research , biochemistry , dna , in vitro
Etoposide (ETO) is a commonly used chemotherapeutic drug that inhibits topoisomerase II activity, thereby leading to genotoxicity and cytotoxicity. However, ETO has limited application due to its side effects on normal organs, especially the kidney. Here, we report the mechanism of ETO-induced cytotoxicity progression in human kidney proximal tubule (HK-2) cells. Our results show that ETO perpetuates DNA damage, activates mitogen-activated protein kinase (MAPK), and triggers morphological changes, such as cell and nuclear swelling. When NAC, a well-known reactive oxygen species (ROS) scavenger, is co-treated with ETO, it inhibits an ETO-induced increase in mitochondrial mass, mitochondrial DNA ( ND1 and ND4 ) copy number, intracellular ATP level, and mitochondrial biogenesis activators ( TFAM, PGC-1α and PGC-1β ). Moreover, co-treatment with ETO and NAC inhibits ETO-induced necrosis and cell swelling, but not apoptosis. Studies using MAPK inhibitors reveal that inhibition of extracellular signal regulated kinase (ERK) protects ETO-induced cytotoxicity by inhibiting DNA damage and caspase 3/7 activity. Eventually, ERK inhibitor treated cells are protected from ETO-induced nuclear envelope (NE) rupture and DNA leakage through inhibition of caspase activity. Taken together, these data suggest that ETO mediates cytotoxicity in HK-2 cells through ROS and ERK pathways, which highlight the preventive avenues in ETO-induced cytotoxicity in kidney.