Vanadium compounds discriminate hepatoma and normal hepatic cells by differential regulation of reactive oxygen species.
Our previous study indicated that vanadium compounds can block cell cycle progression at the G1/S phase in human hepatoma HepG2 cells via a highly activated extracellular signal-regulated protein kinase (ERK) signal. To explore their differential action on normal cells, we investigated the response of an immortalized hepatic cell line, L02 cells. The results demonstrated that a higher concentration of vanadium compounds was needed to inhibit L02 proliferation, which was associated with S and G2/M cell cycle arrest. In addition, in contrast to insignificant reactive oxygen species (ROS) generation in HepG2 cells, all of the vanadium compounds resulted significant increases in both O2.- and H2O2 levels in L02 cells. At the same time, ERK and c-Jun N-terminal kinase (JNK) as well as cell division control protein 2 homolog (Cdc2) were found to be highly phosphorylated, which could be counteracted with the antioxidant N-acetylcysteine (NAC). The current study also demonstrated that both the ERK and the JNK pathways contributed to the cell cycle arrest induced by vanadium compounds in L02 cells. More importantly, it was found that although NAC can ameliorate the cytotoxicity of vanadium compounds in L02 cells, it did not decrease their cytotoxicity in HepG2 cells. It thus shed light on the potential therapeutic applications of vanadium compounds with antioxidants as synergistic agents to reduce their toxicities in human normal cells without affecting their antitumor activities in cancer cells.
Wang
Qin
Q
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, People's Republic of China.
Liu
Tong-Tong
TT
Fu
Ying
Y
Wang
Kui
K
Yang
Xiao-Gai
XG
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008099:Liver / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D017968:Vanadium Compounds / Q000494:pharmacology*
D000975:Antioxidants; D017382:Reactive Oxygen Species; D017968:Vanadium Compounds; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D000111:Acetylcysteine