Ultrastructural Characterization of the New NG97ht Human-Derived Glioma Cell Line Using Two Different Electron Microscopy Technical Procedures

On the basis of transmission electron microscopy observations in tumor cell lines, oncologists have made innumerous diagnostic and therapeutical progresses. Following this path, the UNICAMP immunopathologies laboratory established the NG97 cell line derived from a human astrocytoma grade III, which when injected to the athymic nude mouse flank developed a grade IV astrocytoma. In this study, we focused on ultrastructural characterization of the NG97 cells after being recovered from xenotransplant (NG97ht). These cells in culture were assayed by two different electron microscopy procedures to characterize ultrastructures related to grade IV astrocytomas and to observe their structures through cell subcultivation. Additionally, compara- tive morphological descriptions of different cell passages in these technical procedures could be a useful tool for improving electron microscopy cell lineage protocols. Results from many cell pas- sage observations showed ultrastructural similarities, which suggest malignant and glioblastoma phenotypes. In the first procedure, NG97ht cells were harvested and then incorporated into aga- rose before subjecting them to electron microscopy protocols, whereas in the second one, mono- layer cells grew first on cover slides. Comparison among protocols revealed that organelles, cyto- plasmatic extensions, spatial conformation of filopodia, and cell attachment to substrate were more preserved in the second procedure. Furthermore, in this latter procedure, a unique ellipsoi- dal structure was observed, which was already described when dealing with gliosarcoma cell line elsewhere. Therefore, these analyses demonstrated a morphological characterization of a new NG97ht cell line using electron transmission microscopy. Moreover, it has been shown that the second procedure provides more detailed information compared with the first. Microsc. Res. Tech.