Shikonin time-dependently induced necrosis or apoptosis in gastric cancer cells via generation of reactive oxygen species.
The effects of shikonin on gastric cancer cells were investigated in this study. Exposure to shikonin reduced the viability of gastric cancer cells in a time- and dose-dependent manner. However, apoptosis was not observed in gastric cancer cell treatment with different concentrations of shikonin for 6h. By contrast, treatment with shikonin for 24h significantly induced apoptosis, as evidenced by the results of TUNEL assay and flow cytometry analysis in proportion to the concentration. Disruption of the mitochondrial membrane potential was observed in gastric cancer cells that were treated with shikonin for 6 and 24h. Pretreatment with necrostatin-1 recovered cell death and mitochondrial membrane potential in the 6h shikonin treatment, but not in the 24h shikonin treatment. Western blot results reveal enhanced p38 phosphorylation, downregulated AKT phosphorylation, and increased caspase3 and PARP cleavage in cells that were treated with shikonin for 24h, but not in cells treated for 6h. Shikonin also triggered reactive oxygen species (ROS) generation both in the 6 and 24h treatments. Pretreatment with N-acetylcysteine blocked shikonin-induced cell death. In summary, our findings suggest that shikonin, which may function as a promising agent in the treatment of gastric cancers, sequentially triggered necrosis or apoptosis through ROS generation in gastric cancer cells.
Cardiovascular Center, Antai Tian-Sheng Memorial Hospital, Pingtung 92843, Taiwan.
Mu-Jang
MJ
Lee
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 40201, Taiwan.
Shao-Hsuan
SH
Kao
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 40201, Taiwan.
Jing-En
JE
Hunag
Institute of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan.
Gwo-Tarng
GT
Sheu
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 40201, Taiwan.
Chi-Wei
CW
Yeh
Department of Cosmeceutics, College of Pharmacy, China Medical University, Taichung 40402, Taiwan.
You-Cheng
YC
Hseu
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 40201, Taiwan; Clinical Laboratory, Chung Shan Medical University Hospital, Taichung 40201, Taiwan. Electronic address: wcj@csmu.edu.
Chau-Jong
CJ
Wang
Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 40201, Taiwan; Clinical Laboratory, Chung Shan Medical University Hospital, Taichung 40201, Taiwan. Electronic address: lshsu405@yahoo.com.tw.
Li-Sung
LS
Hsu
D000111:Acetylcysteine / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D009285:Naphthoquinones / Q000494:pharmacology*; D009336:Necrosis / Q000139:chemically induced*; D010766:Phosphorylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000473:pathology; D013997:Time Factors
D000970:Antineoplastic Agents; D016166:Free Radical Scavengers; D009285:Naphthoquinones; D017382:Reactive Oxygen Species; C016101:shikonin; D000111:Acetylcysteine
Apoptosis; Gastric cancer; Necrosis; Shikonin