AKT serine/threonine protein kinase modulates baicalin-triggered autophagy             in human bladder cancer T24 cells.
Baicalin is one of the major compounds in the traditional Chinese medicinal herb from Scutellaria baicalensis Georgi. We investigated the molecular mechanisms of cell autophagy induced by baicalin in human bladder cancer T24 cells. Baicalin inhibited cell survival as shown by MTT assay and increased cell death by trypan blue exclusion assay in a concentration-dependent manner. Baicalin did not induce apoptotic cell death in T24 cells by TUNEL and caspase-3 activity assay. Baicalin induced the acidic vesicular organelle cell autophagy marker, manifested by acridine orange (AO) and monodansylcadaverine (MDC) staining and cleavage of microtubule-associated protein 1 light chain 3 (LC3). The protein expression levels of the Atg 5, Atg 7, Atg 12, Beclin-1 and LC3-II were upregulated in T24 cells after baicalin treatment. Inhibition of autophagy by 3-methyl-adenine (an inhibitor of class III phosphatidylinositol-3 kinase; 3-MA) reduced the cleavage of LC3 in T24 cells after baicalin treatment. Furthermore, protein expression levels of phospho-AKT (Ser473) and enzyme activity of AKT were downregulated in T24 cells after baicalin treatment. In conclusion, baicalin triggered cell autophagy through the AKT signaling pathway in T24 cells.
Department of Physiology, China Medical University, Taichung                     404, Taiwan, R.O.C.
Chingju
C
Lin
Shih-Chang
SC
Tsai
Michael T
MT
Tseng
Shu-Fen
SF
Peng
Sheng-Chu
SC
Kuo
Meng-Wei
MW
Lin
Yuan-Man
YM
Hsu
Miau-Rong
MR
Lee
Sakae
S
Amagaya
Wen-Wen
WW
Huang
Tian-Shung
TS
Wu
Jai-Sing
JS
Yang
D000165:Acridine Orange; D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis; D001343:Autophagy / Q000187:drug effects*; D000071192:Autophagy-Related Protein 12; D000071187:Autophagy-Related Protein 5; D000071193:Autophagy-Related Protein 7; D000071186:Beclin-1; D002103:Cadaverine / Q000031:analogs & derivatives; D053148:Caspase 3; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D008516:Medicine, Chinese Traditional; D008565:Membrane Proteins / Q000096:biosynthesis; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D025841:Small Ubiquitin-Related Modifier Proteins / Q000096:biosynthesis; D011503:Transglutaminases / Q000037:antagonists & inhibitors; D044764:Ubiquitin-Activating Enzymes / Q000096:biosynthesis; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy*
C466624:ATG12 protein, human; C502778:ATG5 protein, human; D051017:Apoptosis Regulatory Proteins; D000071192:Autophagy-Related Protein 12; D000071187:Autophagy-Related Protein 5; C491997:BECN1 protein, human; D000071186:Beclin-1; D004791:Enzyme Inhibitors; D005419:Flavonoids; C477012:MAP1LC3A protein, human; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D000081082:Phosphoinositide-3 Kinase Inhibitors; D025841:Small Ubiquitin-Related Modifier Proteins; C038044:baicalin; C025946:3-methyladenine; D011503:Transglutaminases; D051057:Proto-Oncogene Proteins c-akt; D053148:Caspase 3; C509349:ATG7 protein, human; D000071193:Autophagy-Related Protein 7; D044764:Ubiquitin-Activating Enzymes; D000165:Acridine Orange; C008542:monodansylcadaverine; D000225:Adenine; D002103:Cadaverine