Heterogeneity of keratin intermediate filaments expression in human gliomacell lines

Keratin intermediate filaments (Ifs) are specific for epithelial cell diffe rentiation. This study demonstrates the presence of keratin in two recently established human glioblastoma cell lines 8-MG-BA and 42-MG-BA. Immunofluo rescence staining was performed on cells within passage 230 to 235 using mo noclonal pan-cytokeratin antibodies. The cells were analyzed during several DIV at different cell density. Keratin-positive stained cells reached 5 to 7% in 8-MG-BA and less than 0.1% in 42-MG-BA cell line. The presence of ke ratin-positive cells was independent on cell density and days in vitro. Ker atin-positive cells appeared unevenly distributed in both cell lines. They were observed as single or areas of keratin-positive cells. The morphologic al features of Keratin-positive and keratin-negative cells were similar. Th e results are discussed with respect to previous studies on glial fibrillar y acidic protein (GFAP) and vimentin to show the heterogeneity of Ifs expre ssion in glioma cell lines.