Presence of MHC-I in rat glioma cells expressing antisense IGF-I-receptor RNA.

The supposed immunogenic character of glioma cells transfected with antisense IGF-I-Receptor (IGF-I-R) expression vector was tested for the presence of MHC-I currently present in cells of IGF-I antisense type. C6 rat glioma cell line was comparatively transfected in vitro with IGF I antisense (pMT-Anti-IGF I) or IGF I Receptor antisense (pMT-Anti-IGF I R) expression vectors. The wild and transfected cells were examined for the presence of IGF-I and MHC-I molecules. Using RT PCR technique, the transfected "antisens" cells showed total inhibition of IGF-I. The both transfected cultures of IGF-I and of IGF-I-R type were positively stained for MHC-I. Moreover "antisense IGF-I-R" cells as compared to "IGF-I antisense" cells showed slightly higher expression of MHC-I. The transfected cells showed also the feature of apoptosis in 60% of cells. The immunogenicity of IGF-I-R antisense glioma cells is related to MHC-I presence; therefore both approaches of antisense IGF-I and of antisense IGF-I-R could be use in paralel for cellular therapy of glioblastoma.

IGF-I triple helix gene therapy of rat and human gliomas.

PURPOSE: IGF-I anti-gene technology was applied in treatment of rat and human gliomas using IGF-I triple helix approach. MATERIAL AND METHODS: CNS-1 rat glioma cell and primary human glioblastoma cell lines established from surgically removed glioblastomas multiforme were transfected in vitro with IGF-I antisense (pMT-Anti-IGF-I) or IGF-I triple helix (pMT-AG-TH) expression vectors. The transfected cells were examined for immunogenicity (immunocytochemistry and flow cytometry analysis) and apoptosis phenomena (electron microscopy). 3 x 10(6) transfected cells were inoculated subcutaneously either into transgenic Lewis rats or in patients with glioblastoma. The peripheral blood lymphocytes (PBL) derived from "vaccinated" patients were immunophenotyped for the set of CD antigens (CD4, CD8 etc). RESULTS: Using immunocytochemistry and Northern blot techniques, the transfected "antisense" and "triple-helix" cells showed total inhibition of IGF. Transfected cultures were positively stained either for both MHC-I and B7 antigens--60% of cloned lines, or for MHC-I only--40% of cloned lines. Moreover "triple helix" cells as compared to "antisense" cells showed slightly higher expression of MHC-I or B7. Transfected cells also showed the feature of apoptosis in 60%-70% of cells. In in vivo experiments with rats bearing tumors, the injection of "triple helix" cells expressing both MHC-I and B7 interrupted tumor growth in 80% of cases. In contrast, transfected cells expressing only MHC-I stopped development in 30% of tumors. In five patients with surgically resected glioblastoma who were inoculated with "triple helix" cells, PBL showed an increased percentage of CD4 + CD25+ and CD8 + CD11b-cells, following two vaccinations. CONCLUSIONS: The anti-tumor effectiveness of IGF-I anti-gene technology may be related to both MHC-I and B7 expression in cells used for therapy. The IGF-I antigene therapy of human glioblastoma multiforme increases immune response of treated patients.