The effect of interferon and anti-CD44 antibody on mouse glioma invasiveness in vitro

In this study the effect of interferon and anti-CD44 antibody on the invasi veness of mouse glioma G-26 cells was evaluated. We confirmed the glial nat ure of G-26 glioma cells (G-26) in vitro and in vivo using immunohistochemi stry: G-26 stained strongly for S-100 and stained weakly for glial fibrilla ry acidic protein (GFAP). Immunohistochemical evaluation for CD44 adhesion molecule showed that G-26 was positive both in vitro and in vivo. Weakly po sitive punctate staining for CD44 was seen in the cytoplasm of all viable g lioma cells and focally strong staining was observed in a membranous patter n in the invading glioma cells. Evaluation of untreated G-26 cells using an in vitro invasion assay showed that they were able to digest a Matrigel ma trix and to invade through an 8 mu m microporous membrane. Treatment of the G-26 glioma cells for 3-4 days with mouse interferon alpha/beta at 8 x 10( 2) or 8 x 10(3) mu/ml resulted in a significant decrease of invasiveness: 6 8.8% (p<0.05) and 32.8% (p<0.001) of cells, respectively, remained invasive when compared to control. Treatment of G-26 with antibody to the CD44 adhe sion molecule significantly decreased invasiveness with 39.4% (p<0.001) of cells remaining invasive when compared to control. We feel that both of the se approaches, each of which produced significant inhibition of G-26 glioma cell invasion should be further evaluated for their usefulness in antiglio ma therapy.