Characterisation of human tumour cell lines using antibodies to intermediate filaments

The human hepatoma cell line G2 (Hep G2) has been compared to lung carcinoma, sarcoma and skin fibroblasts for the expression of intermediate filaments, i.e. vimentin and cytokeratin. The immunofluorescence study revealed that, in contradiction to Szecheng et al. (1987), cytokeratin and vimentin are absent in Hep G2. Human skin fibroblasts and sarcoma cells expressed vimentin as expected for their mesenchymal origin, but a positive reaction to vimentin could also be shown in lung carcinoma cells. However, the vimentin filament structure of both these tumour cell lines was different in comparison with skin fibroblasts. Therefore determining the exact tissue origin of tumour cell lines by means of intermediate filament characterization remains doubtful.