Mechanism of Glioblastoma Treatment Targeting Growth Factors: IGF-I Case Using Gene, Immune, Phytochemicals, and Nanotechnologies

Glioblastoma multiforme (GBM), a fatal malignant brain tumor, represents a challenge in terms of developing new treatments. Solutions have been proposed in connection with anti-tumor immune responses, generally T cell strategies, including techniques targeting growth factors, particularly IGF-I, the primary cancer growth factor, and its signal transduction pathways. The objective of this review is to assess the immunogene mechanism targeting IGF-I, which constitutes the basis of the described cancer gene therapy for GBM, stemming from brain neoplastic development studies. The GBM gene therapy, based on new strategies of anti-gene IGF-I techniques, including antisense or triple helix, has been combined with phytochemicals (phenolics) and nanotechnologies (theranostic nanoparticles). The three approaches have modulated IGF-I expression together, inducing common signal transduction pathways: IGF-I-R, TK/PI3K/AKT/TLR/MAPK & JAK/STAT. These signals have transformed in vitro neoplastic glioma cells into immunogenic cells. These immunogenic cells, which express MHC-1 and B7, produce a strong T CD8 anti-tumour immune response after in vivo injection. The combined strategy of anti-IGF-I/phytochemical/nanotechnology vaccines has shown promising clinical results, with patient survival of up to two and three years in some cases. The obtained results are discussed in parallel with other immunotherapies and antitumour vaccine studies that involve the immunogenicity mechanism.