Influence of EMAP II, IFN-α2b and its medicinal preparations on the MGMT protein amount in human cells in vitro

Aim. To study the effect of EMAP II, IFN-α2b and its medicinal preparations on the amount of O6-methylguanine-DNA methyltransferase (MGMT) protein in human cells in vitro. Methods. The human cells of 4BL and Hep-2 lines were treated with the purified recombinant proteins EMAP II, IFN-α2b and its commercial me dicinal preparations. Changes in the MGMT gene expression were studied at a protein level by Western blot analysis. Results. Treatment of Hep-2 and 4BL cells with EMAP II at the concentrations of 0.02 mg/ml and 2 mg/ml respectively led to induction of the MGMT gene expression. EMAP II at the concentrations of 0.2–20 g/ml caused decrease of the MGMT protein amount in Hep-2 cells. The regulating activity of EMAP II was also observed for MARP (anti-Methyltransferase Antibody Recognizable Protein). IFN-α2b and Laferon-PharmBiotek with the activity of 200 and 2000 IU/ml were shown to cause an increase of the MGMT protein amount in Hep-2 cells. Conclusions. The purified recombinant proteins EMAP II and IFN-α2b which are substrates for the medicinal preparations influenced on the amount of MGMT protein in the human cell cultures in a concentration-dependent manner. At the same time the effect of medicinal preparations differs from that of the purified protein IFN-α2b. Possibly it depends on the presence of stabilizing components in their compositions.