H. Ikeda et al., INTERLEUKIN-1-BETA CONVERTING-ENZYME (ICE) IS PREFERENTIALLY EXPRESSED IN NEUROBLASTOMAS WITH FAVORABLE PROGNOSIS, European journal of cancer, 33(12), 1997, pp. 2081-2083
To determine whether interleukin-1 beta converting enzyme (ICE) plays
a role in the programmed cell death of neuroblastoma, we studied ICE e
xpression in primary tumours. In patients in stages I, II and IVS, ICE
mRNA was detected in 22 of 32 (69%) tumours, while only 5 of 26 (19%)
tumours expressed ICE in stages III and IV (P<0.001). ICE mRNA was ex
pressed in 27 of 47 (57%) tumours without MYCN amplification, but it w
as not detected in any tumours with MYCN amplification (P<0.01). Immun
ohistochemically, the cytoplasm was stained in all 15 neuroblastomas e
xamined. The nuclei were stained in 12 neuroblastomas without MYCN amp
lification, whereas only 1 of 3 tumours with MYCN amplification had po
sitive staining in the nuclei. In ganglioneuromas, high levels of ICE
mRNA were expressed, but immunostaining showed that the protease expre
ssion was confined to the cytoplasm. These observations suggest that I
CE may be associated with the spontaneous regression often seen in fav
ourable neuroblastomas and that localisation of ICE protease in the ce
ll may be important for the cell death pathway. Double staining for IC
E and TUNEL showed that they were co-localised in some nuclei, but the
distribution of ICE protease expression was not necessarily the same
as that of DNA fragmentation, suggesting that the protease expression
probably preceded DNA fragmentation during the apoptotic process. ICE
may play an important role in regulating the apoptotic process of neur
oblastoma. (C) 1997 Elsevier Science Ltd.