Object: Galectin-1 is highly expressed in motile cell lines. The authors investigated whether galectin-1 actually modulates the migration and invasion of human glioblastoma multiforme (GBM) cell lines, and whether its expression with respect to invasion and prognosis is attributable to certain glioma subgroups.
Methods: In the human GBM cell lines U343MG-A, U87MG, and U87MG-10', the RNA differential display was evaluated using Genefishing technology. The results were validated by reverse transcription polymerase chain reaction and Northern blot analysis to detect possible genetic changes as the determining factors for the motility of the malignant glioma. The migration and invasion abilities were investigated in human GBM cell lines and galectin-1 transfectant using an in vitro brain slice invasion model and a simple scratch technique. The morphological and cytoskeletal (such as the development of actin and vimentin) changes were examined under light and confocal microscopy. Galectin-1 expression was assessed on immunohistochemical tests and Western blot analysis.
Results: Endogenous galectin-1 expression in the human GBM cell lines was statistically correlated with migratory abilities and invasiveness. The U87-G-AS cells became more round than the U87MG cells and lacked lamellipodia. On immunohistochemical staining, galectin-1 expression was increased in higher-grade glioma subgroups (p = 0.027).
Conclusions: Diffuse gliomas demonstrated higher expression levels than pilocytic astrocytoma in the Western blot. Galectin-1 appears to modulate migration and invasion in human glioma cell lines and may play a role in tumor progression and invasiveness in human gliomas.