Apoptosis in non-astrocytic brain tumours in children

Apoptosis is a process of great significance in cell biology. It plays a crucial role in both physiological and pathological conditions. An example is a tumour growth that is based on a subtle balance between cell division and cell death. Previously necrosis was considered to be the major type of cell death in tumours. Many recent investigations have focused on apoptosis, a phenomenon of great importance, and it is this type of cell death that is frequently "chosen" by a moribund cell. The objects of our interest were central nervous system (CNS) tumours, in which we estimated the number of apoptotic cells and sought for any correlation between the intensity of apoptosis and other markers of proliferation. Therefore, we studied CD34, the marker of angiogenesis, and Ki67, the marker of cell proliferation. We investigated 19 medulloblastomas and 15 ependymomas, among which 6 were anaplastic. We used in-situ labelling of DNA fragments to detect apoptosis in paraffin-embedded tissues. The mean value of the apoptotic ratio (AR) for all examined brain tumours was 0.012 with a standard deviation (SD) of 0.032, for medulloblastomas 0.021 (SD 0.04), for ependymomas 0.001 (SD 0.002) and for anaplastic ependymomas 0.004 (SD 0.003).