Fisetin-induced apoptosis of human oral cancer SCC-4 cells through reactive oxygen species production, endoplasmic reticulum stress, caspase-, and mitochondria-dependent signaling pathways.
Oral cancer is one of the cancer-related diseases in human populations and its incidence rates are rising worldwide. Fisetin, a flavonoid from natural products, has been shown to exhibit anticancer activities in many human cancer cell lines but the molecular mechanism of fisetin-induced apoptosis in human oral cancer cells is still unclear; thus, in this study, we investigated fisetin-induced cell death and associated signal pathways on human oral cancer SCC-4 cells in vitro. We examined cell morphological changes, total viable cells, and cell cycle distribution by phase contrast microscopy and flow cytometry assays. Reactive oxygen species (ROS), Ca2+, mitochondria membrane potential (ΔΨm), and caspase-8, -9, and -3 activities were also measured by flow cytometer. Results indicate that fisetin induced cell death through the cell morphological changes, caused G2/M phase arrest, induction of apoptosis, promoted ROS and Ca2+production, and decreased the level of ΔΨmand increased caspase-3, -8, and -9 activities in SCC-4 cells. DAPI staining and DNA gel electrophoresis were also used to confirm fisetin-induced cell apoptosis in SCC-4 cells. Western blotting also found out that Fisetin increased the proapoptotic proteins such as Bax and Bid and decreased the antiapoptotic proteins such as Bcl-2. Furthermore, results also showed that Fisetin increased the cytochrome c, AIF, and Endo G release from mitochondria in SCC-4 cells. We also used ATF-6α, ATF-6β, GADD153, and GRP78 which indicated that fisetin induced cell death through ER stress. Based on those observations, we suggest that fisetin induced cell apoptosis through ER stress, mitochondria-, and caspase-dependent pathways.
Department of Biological Science and Technology, China Medical University, Taichung, Taiwan.
Chen-Hsuan
CH
Su
Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, 404, Taiwan.
Chao-Lin
CL
Kuo
College of Chinese Medicine, School of Post-Baccalaureate Chinese Medicine, China Medical University, Taichung, 404, Taiwan.
Kung-Wen
KW
Lu
School of Dentistry, China Medical University, Taichung, 404, Taiwan.
Fu-Shun
FS
Yu
School of Chinese Medicine for Post-Baccalaureate, I-Shou University, Kaohsiung, 84001, Taiwan.|Department of Chinese Medicine, E-Da Hospital, Kaohsiung, 82445, Taiwan.
Yi-Shih
YS
Ma
Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, 404, Taiwan.
Jiun-Long
JL
Yang
International Master's Degree Program in Food Science, International College, National Pingtung University of Science and Technology, Pingtung, 91201, Taiwan.
Yung-Lin
YL
Chu
Department of Health and Nutrition Biotechnology, Asia University, Taichung, 413, Taiwan.
Fu-Shin
FS
Chueh
Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan.
Kuo-Ching
KC
Liu
Department of Biological Science and Technology, China Medical University, Taichung, Taiwan.|Department of Biotechnology, Asia University, Wufeng, Taichung, Taiwan.
Jing-Gung
JG
Chung
D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D020169:Caspases / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D005419:Flavonoids / Q000494:pharmacology*; D044948:Flavonols; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009062:Mouth Neoplasms / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction
D016588:Anticarcinogenic Agents; D051017:Apoptosis Regulatory Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D005419:Flavonoids; D044948:Flavonols; C000717247:HSPA5 protein, human; D017382:Reactive Oxygen Species; D045304:Cytochromes c; D020169:Caspases; C017875:fisetin
DNA ladder; Fisetin; SCC-4 cells; apoptosis; mitochondria