During prolonged cultivation, cell lines may lose a number of innate characteristics or acquire new ones. In this work, we compared growth and phenotypic characteristics of human glioblastoma А172 and Т98G cell lines received from the cell culture collection of the Research Institute of Influenza (St. Petersburg, Russia). The activity of genes encoding intracellular proteins that define belonging of these cell lines to mesenchymal type, as well as activity of several growth factor genes and extracellular matrix genes was evaluated. Cell lines A172 and T98G varied in morphology and surface markers expression. High level of mesenchymal markers CD90 and CD105, fibroblast activation protein, and tenascin C was detected for A172 cell line. Both cell lines expressed high level of α2 smooth muscle actin gene. Data demonstrating high activity of genes encoding major angiogenesis inductors (VEGF, FGF2(b), TGFβ1) and thrombospondin-1 in cell lines under study are in agreement with published data. Reduction of fetal serum content in culture medium from 10 to 5% increased the number of cells with CD73 and CD105 surface antigens in both cell lines. A172 and T98G cell lines maintain the main features of glioblastomas and therefore can be used as research objects in investigation of this type of neoplasms.