title: Kaempferol induces autophagy through AMPK and AKT signaling molecules and causes G2/M arrest via downregulation of CDK1/cyclin B in SK-HEP-1 human hepatic cancer cells.
abstract: Kaempferol belongs to the flavonoid family and has been used in traditional folk medicine. Here, we investigated the antitumor effects of kaempferol on cell cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells. Kaempferol decreased cell viability as determined by MTT assays and induced a G2/M phase cell cycle arrest in a concentration-dependent manner. Kaempferol did not induce DNA fragmentation, apoptotic bodies or caspase-3 activity in SK-HEP-1 cells as determined by DNA gel electrophoresis, DAPI staining and caspase-3 activity assays, respectively. In contrast, kaempferol is involved in the autophagic process. Double-membrane vacuoles, lysosomal compartments, acidic vesicular organelles and cleavage of microtubule-associated protein 1 light chain 3 (LC3) were observed by transmission electron microscopy, LysoΤracker red staining, GFP-fluorescent LC3 assays and acridine orange staining, respectively. In SK-HEP-1 cells, kaempferol increased the protein levels of p-AMPK, LC3-II, Atg 5, Atg 7, Atg 12 and beclin 1 as well as inhibited the protein levels of CDK1, cyclin B, p-AKT and p-mTOR. Taken together, CDK1/cyclin B expression and the AMPK and AKT signaling pathways contributed to kaempferol-induced G2/M cell cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells. These results suggest that kaempferol may be useful for long-term cancer prevention.
authors.affiliation: Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan, R.O.C.
authors.forename: Wen-Wen
authors.initials: WW
authors.lastname: Huang
authors.forename: Shih-Chang
authors.initials: SC
authors.lastname: Tsai
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Peng
authors.forename: Meng-Wei
authors.initials: MW
authors.lastname: Lin
authors.forename: Jo-Hua
authors.initials: JH
authors.lastname: Chiang
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chiu
authors.forename: Shinji
authors.initials: S
authors.lastname: Fushiya
authors.forename: Michael T
authors.initials: MT
authors.lastname: Tseng
authors.forename: Jai-Sing
authors.initials: JS
authors.lastname: Yang
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D019926:Cyclin B / Q000378:metabolism*; D015536:Down-Regulation; D006801:Humans; D044949:Kaempferols / Q000494:pharmacology*; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D019926:Cyclin B; D044949:Kaempferols; C502070:MAP1LC3B protein, human; D008869:Microtubule-Associated Proteins; C006552:kaempferol; C546842:MTOR protein, human; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D055372:AMP-Activated Protein Kinases; D053148:Caspase 3