PP2S7008

PP2 inhibits Src by binding to an area of the molecule that does not overlap with the ATP binding domain. ^[2] PP2 (20 μM) induces 40-50% growth inhibition of HT29 cells, this concentration reduces the Src activity as early as 1 hour and maintains a 35% inhibition of Src activity for 2 days. PP2 (100 mM) decreases the Src activity of HT29 cells in a dose-dependent manner. PP2 (1 mM-100 mM) causes a dose-dependent growth inhibition of human colon cancer cells (HT29, SW480, and PMCO1), liver cancer cells (PLC/PRF/5, KYN-2, Li7, and HepG2), and breast cancer cells (MCF-7, MDA-MB-468, and BT-474). PP2 (20 μM) significantly increases aggregation in most of the cancer cells (HT29, SW480, PMCO1, PLC/PRF/5, KYN-2, Li7, MCF-7, and MDA-MB-468) in E-cadherin dependent manner. PP2 (20 μM) enhances E-cadherin expression and also strongly increases E-cadherin’s association with the actin cytoskeleton in cancer cells. PP2 (20 μM) increases the expression of α-catenin, β-catenin, and γ-catenin in HT29 cells, whereas in PLC/PRF/5 and MCF-7 cells, the total protein level of α-catenin does not change, but the levels of β- catenin and γ-catenin increases slightly. ^[3] PP2 inhibits proliferation of two cervical cancer cells (HeLa and SiHa) in a time- and dose-dependent manner. PP2 (10 μM) down-regulates pSrc-Y416, pEGFR-Y845, and -Y1173 expression levels in HeLa and SiHa cells. PP2 (10 μM) could modulate cell cycle arrest by up-regulating p21(Cip1) and p27(Kip1) in both HeLa and SiHa cells and down-regulating expression of cyclin A, and cyclin dependent kinase-2, -4 (Cdk-2, -4) in HeLa and of cyclin B and Cdk-2 in SiHa. ^[4]