acacetin and Stomach-Neoplasms

Epithelial-to-mesenchymal transition (EMT) is a pivotal cellular phenomenon involved in tumour metastasis and progression. In gastric cancer (GC), EMT is the main reason for recurrence and metastasis in postoperative patients. Acacetin exhibits various biological activities. However, the inhibitory effect of acacetin on EMT in GC is still unknown. Herein, we explored the possible mechanism of acacetin on EMT in GC in vitro and in vivo.. In vitro, MKN45 and MGC803 cells were treated with acacetin, after which cell viability was detected by CCK-8 assays, cell migration and invasion were detected by using Transwell and wound healing assays, and protein expression was analysed by western blots and immunofluorescence staining. In vivo, a peritoneal metastasis model of MKN45 GC cells was used to investigate the effects of acacetin.. Acacetin inhibited the proliferation, invasion and migration of MKN45 and MGC803 human GC cells by regulating the expression of EMT-related proteins. In TGF-β1-induced EMT models, acacetin reversed the morphological changes from epithelial to mesenchymal cells, and invasion and migration were limited by regulating EMT. In addition, acacetin suppressed the activation of PI3K/Akt signalling and decreased the phosphorylation levels of TGF-β1-treated GC cells. The in vivo experiments demonstrated that acacetin delayed the development of peritoneal metastasis of GC in nude mice. Liver metastasis was restricted by altering the expression of EMT-related proteins.. Our study showed that the invasion, metastasis and TGF-β1-induced EMT of GC are inhibited by acacetin, and the mechanism may involve the suppression of the PI3K/Akt/Snail signalling pathway. Therefore, acacetin is a potential therapeutic reagent for the treatment of GC patients with recurrence and metastasis.

Topics: Animals; Cell Line, Tumor; Cell Movement; Disease Models, Animal; Epithelial-Mesenchymal Transition; Flavones; Humans; Male; Mice; Mice, Inbred BALB C; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Snail Family Transcription Factors; Stomach Neoplasms; Transforming Growth Factor beta1

Acacetin (5,7-dihydrocy-4'-methoxy flavone), which is a flavonoid compound, possesses anti-peroxidative and anti-inflammatory effects. The effects of acacetin on cell viability in human gastric carcinoma AGS cells were investigated. This study demonstrated that acacetin was able to inhibit cell proliferation and induce apoptosis in a concentration- and time-dependent manner. Acacetin-induced cell death was characterized with changes in nuclear morphology, DNA fragmentation, and cell morphology. The molecular mechanism of acacetin-induced apoptosis was also investigated. Treatment with acacetin caused induction of caspase-3 activity in a time-dependent manner, but not caspase-1 activity, and induced the degradation of DNA fragmentation factor (DFF-45) and poly(ADP-riobse) polymerase. Cell death was completely prevented by a pancaspase inhibitor, Z-Val-Ala-Asp-fluoromethyl ketone. Furthermore, treatment with acacetin caused a rapid loss of mitochondrial transmembrane potential, stimulation of reactive oxygen species (ROS), release of mitochondrial cytochrome c into cytosol, and subsequent induction of procaspase-9 processing. Antioxidants such as N-acetylcysteine and catalase, but not superoxide dismutase, allopurinol, or pyrrolidine dithiocarbamate, significantly inhibited acacetin-induced cell death. In addition, it was found that acacetin promoted the up-regulation of Fas and FasL prior to the processing and activation of pro-caspase-8 and cleavage of Bid, suggesting the involvement of a Fas-mediated pathway in acacetin-induced apoptosis. On the other hand, the results showed that acacetin-induced apoptosis was accompanied by up-regulation of Bax and p53, down-regulation of Bcl-2, and cleavage of Bad. Taken together, these results suggest that ROS production and a certain intimate link might exist between receptor- and mitochondria-mediated death signalings that committed to acacetin-induced apoptosis in AGS cells. The induction of apoptosis by acacetin may provide a pivotal mechanism for its cancer chemopreventive action.

Topics: Apoptosis; Caspase 3; Caspases; Cell Cycle Proteins; Cyclin-Dependent Kinase Inhibitor p21; Enzyme Activation; Flavones; Humans; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Stomach Neoplasms; Tumor Cells, Cultured; Tumor Suppressor Protein p53