ABSTRACT
Aim To study the relationship between the anti-proliferation effect of tetrandrine(Tet) and TGF-β1 in human colon cancer cells.Methods Cell viability assay, Western blot, flow cytometry and Annexin Ⅴ-EGFP staining were introduced to analyze the anti-cancer effect of Tet on HCT116 cells.Real-time PCR, Western blot,cell viability and immunofluorescent were employed to determine the relationship between the anti-cancer effect of Tet and TGF-β1 in HCT116 cells, the relationship between the anti-cancer effect of Tet and PI3K/Akt on HCT116 cells, and how TGF-β1 mediated the anti-cancer effect of Tet on HCT116 cells.Results Compared with the control groups, Tet apparently inhibited the proliferation, and induced cell cycle arrest at G1 phase and apoptosis in HCT116 cells.Tet greatly up-regulated the expression of TGF-β1 either the mRNA or protein level, and exogenous expression of TGF-β1 potentiated the anti-cancer effect of Tet in HCT116 cells, while TGF-β1 inhibitor attenuated it notably.Tet decreased the phosphorylation of Akt1/2/3, but no apparent effect was observed on total protein level of Akt1/2;PI3K inhibitor enhanced the anti-cancer effect of Tet in HCT116 substantially.Exogenous expression of TGF-β1 enhanced the Tet-induced decrease phorphorylation of Akt1/2/3, which was partly reversed by TGF-β1 inhibitor in HCT116 cells.Meanwhile, knockdown of PTEN elevated the level of phorphorylated Akt1/2/3, which was abolished by the exogenous expression of TGF-β1 in HCT116 cells.Conclusion Tet may be a potent candidate drug for colon cancer treatment, and the anti-cancer effect of Tet may be partly mediated by up-regulating TGF-β1 to inactivate PI3K/Akt signal.
ABSTRACT
Several digital filtering techniques for correcting baseline drift from ECG signals are presented. A bidirectional filter is introduced, which can cantain baseline drift their filtering performance and realization methods are compared.