[The Effects of IFN-γ on AKT activated 32D Cells and its Mechanisms].

OBJECTIVE: To investigate the effects of activated AKT on murine myeloid precursor cells (32D cells), and the effects of IFN-γ on 32D cells and its mechanisms. METHODS: Plasmid transduction was used to enhance the expression of AKT on 32D cells. After the transfected cells treated with IFN-γ for 24 hours, proliferation rate was tested by WST-1, apoptosis by flow cytometry, expression of phosphorylated Erk1/2, Stat3 and phosphorylated Stat3 was determined by Western blot. RESULTS: (1) IFN-γ at low concentration (100 U/ml) enhanced the growth and proliferation of 32D cells, while at high concentration (1000 U/ml) suppressed them. (2) Compared with control groups, low concentration IFN-γ increased (1124 ± 13) Stat3 phosphorylation in 32D-cell, while it high concentration IFN-γ decreased (601 ± 13). 32D cells transfected with activated Akt grew rapidly (0.287 ± 0.010) and had a low apoptotic rate [(9.57 ± 0.17)% (P < 0.05)]. (3) The expression of p-Erk1/2 in transfected 32D-cell was significantly reduced (P < 0.05). (4) Apoptosis rate of IFN-γ treated group was significantly decreased in transfected 32D cells (P < 0.05). CONCLUSIONS: IFN-γ has dual effects on 32D cells, namely, at low concentration enhanced the growth and proliferation of 32D cells, while at high concentration suppressed them. Its mechanisims is possibly through Stat3 pathway. Activated Akt can significantly promote the growth and proliferation of 32D cell and significantly inhibit apoptosis and IFN-γ can regulate cell proliferation and apoptosis through AKT. AKT activation can inhibit the Erk signal pathway, which may be affected by inhibition the modificaton of Raf1.