Decreased wild-type full-length Et-A and -B receptors in neuroblastoma andEwing sarcoma cells

Background. Endothelins and their receptors, Et-A and Et-B, play an essenti al role in differentiation and migration of neural crest cells. Expression of endothelin receptors has been examined in neuroblastoma and Ewing sarcom a cell fines. Procedure. RNA was amplified for Et-A and Et-B by RT-PCR. Amp lified products were cloned into the expression vector pLNCX, which was use d to transfect CHO cells. Binding characteristics of transfected CHO cells were examined. Results. Full-length Et-A mRNA was identified in all cell li nes, in addition to a truncated Et-A product. CHO cells expressing full-len gth Et-A bound to endothelin, but cells expressing truncated Et-A did not. Full length Et-B mRNA was not detected, but two smaller molecular weight pr oducts were amplified. These are as yet uncharacterised. Conclusions. These results suggest that endothelins and their receptors may be important in t he development and biology of neuroblastoma and Ewing sarcoma. Med. Pediatr . Oncol. 36: 142-246, 2001. (C) 2001 Wiley-Liss, Inc.