Regulation of neuroectodermal cancers invasive behavior: role of PDE5 in glioblastoma multiforme and of Sox2 in melanoma

Neuroectoderm is one of the earliest cell lineages that establish at gastrulation. Neuroectodermal tumors arise from cells originating from the primitive neuroectoderm, which include glial cells, neurons, neural crest cells, parenchymal cells of the pineal gland and primitive embryonic cells of brain and retina. Both melanocytes and glial cells are derived embryologically from the neuroectoderm. Their malignant transformed counterparts, melanoma and glioma cells, respectively, may share common antigens. Numerous tumor-associated antigens have been identified in melanomas but only a few in gliomas. We undertook a study of how invasiveness of tumor cells can be regulated in gliomas as well as in melanomas, focusing our attention on two genes, Sox2 and PDE5, which have been hypothesized to play a role in melanoma invasiveness. In particular, we modulated PDE5 expression in glioblastoma cell lines and Sox2 in a melanoma animal model to evaluate the invasiveness potential of this tumor cell types in vitro and in vivo.