Table 2: Immunocytochemical staining of IGF-I and of immunogenic antigens MHC-I and -II, and B7 in the rat glioma C6 cells. NT: Non transfected parental cells; pMT-EP: Transfection with "empty vector"; IGF-I or -II AS: Transfection with IGF-I or IGF-II antisense expression vectors; IGF-I TH: Transfection with IGF-I triple helix expression vector; IGF-I AS/IGF-I TH: Co-transfection with antisense and triple helix vectors; IGF-I AS/MHC-I AS/B7 AS, triple co-transfection; Transfected cells were cultured in presence of Zn²⁺, in order to activate the MT-I promotor [5,19], (Figure 3 and Figure 4). The similar results were obtained with HG cells.

*+++labeling corresponding to maximum intensity of staining (dilution of antibodies 1:200); ++labeling corresponding to intermediate intensity of staining (dilution of antibodies 1:100).