12-O-tetradecanoylphorbol-13-acetate-induced invasion/migration of glioblastoma cells through activating PKCalpha/ERK/NF-kappaB-dependent MMP-9 expression.
An increase in MMP-9 gene expression and enzyme activity with stimulating the migration of GBM8401 glioma cells via wound healing assay by 12-O-tetradecanoylphorbol-13-acetate (TPA) was detected in glioblastoma cells GBM8401. TPA-induced translocation of protein kinase C (PKC)alpha from the cytosol to membranes, and migration of GBM8401 elicited by TPA was suppressed by adding the PKCalpha inhibitors, GF109203X and H7. Activation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK) by TPA was identified, and TPA-induced migration and MMP-9 activity was significantly blocked by ERK inhibitor PD98059 and U0126, but not JNK inhibitor SP600125. Activation of NF-kappaB protein p65 nuclear translocation and IkappaBalpha protein phosphorylation with increased NF-kappaB-directed luciferase activity by TPA were observed, and these were blocked by the PD98059 and IkB inhibitor BAY117082 accompanied by reducing migration and MMP-9 activity induced by TPA in GBM8401 cells. Transfection of GBM8401 cells with PKCalpha siRNA specifically reduced PKCalpha protein expression with blocking TPA-induced MMP-9 activation and migration. Additionally, suppression of TPA-induced PKCalpha/ERK/NK-kappaB activation, migration, and MMP-9 activation by flavonoids including kaempferol (Kae; 3,5,7,4'-tetrahydroxyflavone), luteolin (Lut; 5,7,3'4'-tetrahydroxyflavone), and wogonin (Wog; 5,7-dihydroxy-8-methoxyflavone) was demonstrated, and structure-activity relationship (SAR) studies showed that hydroxyl (OH) groups at C4' and C8 are critical for flavonoids' action against MMP-9 enzyme activation and migration/invasion of glioblastoma cells elicited by TPA. Application of flavonoids to prevent the migration/invasion of glioblastoma cells through blocking PKCalpha/ERK/NF-kappaB activation is first demonstrated herein.
Lin
Cheng-Wei
CW
Graduate Institute of Pharmacy, School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
Shen
Shing-Chuan
SC
Chien
Chih-Chiang
CC
Yang
Liang-Yo
LY
Shia
Lin-Ting
LT
Chen
Yen-Chou
YC
D002273:Carcinogens / Q000633:toxicity; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000378:metabolism*; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D015394:Molecular Structure; D016328:NF-kappa B / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D034622:RNA Interference; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity*
D002273:Carcinogens; D005419:Flavonoids; D016328:NF-kappa B; D051571:Protein Kinase C-alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4; D020780:Matrix Metalloproteinase 9; D013755:Tetradecanoylphorbol Acetate