INTRODUCTION: We previously reported expression of CD44(Hyaluronic acid/lymphocyte homing receptor) and CD155 (Poliovirus receptor) on established cell lines and early passage cultures of biopsyderived glioma using immunocytochemistry, TIRF microscopy and flow cytometry. Both receptors have been reported to facilitate glioma invasion. METHODS: Antibody blocking and siRNA silencing of CD44 and CD155 were assessed using Transwell assay and live cell imaging for motility and invasion. A ECM cell adhesion array was used to determine adhesive potential of wild type cells versus silenced cells. BrdU cell proliferation assay was carried out to assess proliferative rate of cells following siRNA knockdown of both CD44 and CD155. Interaction and localisation of CD44 and CD155 with F-actin and integrins (b, avb, and avb3) were shown by confocal and TIRF microscopy. RESULTS: CD44 antibody blocking and gene silencing resulted in a higher level of inhibition of invasion than for CD155. Interference with combined CD44/CD155 resulted in 100% inhibition of invasion. Live cell imaging showed reduced speed of motility of knockdown cells over their controls. Wild type cells adhered most efficiently to laminin whereas siRNA-treated cells showed decreased adhesive potential on most of the ECMs used. A higher proliferative rate of siRNA CD44 and siRNA CD155 treated cells was inversely correlated with the reduced invasion of these cells. Confocal microscopy showed distinct overlapping of CD155 and the integrins on filopodia while TIRF microscopy allowed high signal/low noise imaging of double labelled cells. CONCLUSIONS: Joint CD44/CD155 approaches may merit further study in targeting infiltrating glioma cells in therapeutic protocols.