Study On The Relationship Between IGFBP-5 And The Antiproliferation Effect Of Tetrandrine In MCF-7 Cells

Breast cancer as one of the most malignancies common malignancies,causes considerable morbidity and mortaliy.The current treatment for breast cancer is more modest than had been hoped.To study the effect of Tet on proliferation of MCF-7 breast cancer cells and the possible mechanism underlying this biological process.Crystal violet staining,CCK-8,flow cytometric and Western blot were introduced to analyze the effect of Tet on proliferation and apoptosis in MCF-7 cells.RT-PCR and Western blot assay were employed to detect the effect of Tet on expression of IGFBP-5,p53 and MDM2.CCK-8 and recombinant adenovirus were utilized to determine the effect of IGFBP-5 on the proliferation inhibitory effect of Tet.Western blot assay was introduced to evaluate the effect of IGFBP-5 on p53 which induced by Tet.Tet inhibits the proliferation,arrests cell cycle at G1 phase and decreases the expression of PCNA concentration dependently in MCF-7 cells.Meanwhile,Tet increases the percentage of apoptotic cells,increases the level of Bad and reduces the level of Bcl-2.Tet increases the expression of IGFBP-5 either mRNA or protein,exogenous IGFBP-5 enhances the anti-proliferation activity of Tet in MCF-7 cells,but knockdown of IGFBP-5 attenuates this effect of Tet.Tet increases the level of p53 and decreases the level of MDM2,exogenous IGFBP-5 enhances the effect of Tet on p53 and MDM2,respectively.Tet can inhibit the proliferation of MCF-7 cells,this activity is partly mediated by increasing the function of p53,which may be triggered by the Tet-induced IGFBP-5.