The expression of apoptosis-related proteins and the apoptotic rate in glial tumors of the brain

Modern molecular biology methods allow a more precise analysis of the biolo gical characteristics of tumors and, consequently, a more precise treatment plan. The determination of apoptotic rate and expression of apoptosis-rela ted proteins belong among the important prognostic/diagnostic markers in ma ny tumors. The validity of these factors had nor yet been sufficiently anal yzed in astroglial tumors. The aim of this work was therefore to study mutu al relationships between apoptotic rate, expression of apoptosis-regulating proteins and some clinical and histopathological data. The TUNEL method was used for the determination of apoptosis in 44 astrogli al tumor specimens. The percentage of TUNEL positive cells was expressed by the TUNEL index (TI). The TI data was compared with the immunohistochemica lly detected expression of proteins involved in apoptosis (BCL-2, FAS, FAS- L, and caspase 1), with grading, age, proliferative activity (assessed by P CNA expression analysis) and overall survival of patients. The statistical evaluation of results was done by two-way sample analysis of variance. We have demonstrated significantly higher values of both TI and expression of FAS-L and caspase 1 in Low grade tumors, which were characterized by a l onger survival, lower average age and a lower expression of PCNA. FAS-L exp ression correlated significantly with the expression of the caspase 1. No s ignificant difference was found between the expression of BCL-2 and FAS. Th ese results suggest that the determination of TI in astroglial tumors may b e an important prognostic marker The expression of FAS-L and caspase 1 in l ow grade astroglial tumors could indicate the increased readiness to apopto sis via the FAS/FAS-L cascade.