Apoptosis, analysed by means of lamin B detection, correlates with grade of astroglial tumours but not with p27(Kip1)/retinoblastoma protein expression

The aim of our study was to correlate apoptosis, assessed by means of lamin B degradation, with grade of tumour and immunohistochemical expression of P27(Kip1) and retinoblastoma protein (pRB) in a series of 32 low-grade astr ocytomas (LGA) and 43 high-grade astrocytomas (HGA). Determination and anal ysis of lamin B expression was achieved stereologically with the use of com puterised interactive image analysis. The average stereological surface den sity of the lamin-positive nuclear surface of cells showing evidence of lam in degradation cells was 13.80 mm(2)/mm(3) in LGA and 21.02 mm(2)/mm(3) in HGA. The average range of immunopositivity of p27 and pRB expression was 2. 85 and 2.10, respectively, in LGA and 1.80 and 0.88, respectively, in HGA. The rate of apoptosis indirectly correlated with the expression of both p27 and pRB but was not fully significant (P less than or equal to0.09). Our f indings suggest that there may be a loss of function of main cell-cycle reg ulators and increased uncontrolled cell death in addition to increased cell proliferation in high-grade astrocytomas. Moreover, we believe that the de tection of lamin B degradation in astroglial tumours can be an alternative, precise and convenient assay for the detection of a defined set of apoptot ic cells. However, before being applied more generally, comparative researc h should be done on different methods of quantifying apoptosis, with the in tent of finding the difference between biologically different methods. Such studies would also be able to find the method associated with the stronges t prognostic power.