Association among EPHB2, TrkA, and MYCN expression in low-stage neuroblastomas

Background. The EPH family is the largest subfamily of receptor protein-tyr osine kinases, consisting of. EPHA and EPHB subgroups. Ligands of EPH famil y receptors are called ephrins, which include ephrin-A and ephrin-B subgrou ps. We recently found that transcripts encoding the EPHB subgroup (EPHB) an d the ephrin-B subgroup (EFNB) were expressed together in neuroblastoma (NB ) cell lines. Procedure, in this study, we examined the expression of EPHB and EFNB transcripts in 24 NE specimens representing all clinical stages. W e found that several EPHB and EFNB transcripts were expressed together in a ll NBs examined. Results Among the transcripts examined, EPHB6 expression w as most significantly associated with low stage tumors (stages 1, 2, and 4S ; P = 0.0048). TrkA expression was significantly correlated with EPHB6 EFNB 2, and EFNB3 expression (P < 0.01 in each case). Taken together, these data indicate that the expression of EPHB6, EFNB2, and EFNB3 may serve as progn ostic indicators of favorable NBs. in the low-stage NBs without MYCN amplif ication, EPHB2 expression was correlated both with MYCN expression and with TrkA expression (P < 0.01 in each case). Moreover, MYCN expression was cor related with TrkA expression (P < 0.01) in the low-stage NBs. Conclusions. This observation points to the possibility that MYCN expression might contr ibute to favorable outcome of low-stage NBs. Med. Pediatr. Oncol. 36:80-82, 2001. (C) 2001 Wiley-Liss. Inc.