Up-regulation of EphB and ephrin-B expression in rhabdomyosarcoma.
BACKGROUND
Increased expression of Eph receptors and their ephrin ligands has been implicated in promoting angiogenesis and tumour progression in several malignancies. Here the expression of mRNA for ephrin-B and EphB receptors in rhabdomyosarcoma (RMS) cell lines and primary tumours was investigated.


METHODS
Expression of mRNA for ephrin-B and EphB receptors in RMS cell lines and primary tumours was measured by real-time RT-PCR and compared with the expression in normal striated muscle.


RESULTS
A dysregulation of both ligands and receptors was found in all cell lines. In embryonal tumours, overexpression of ephrin-B1 correlated with overexpression of EphB1 (r = 0.97, p < 0.01) and EphB3 (r = 0.94, p < 0.05); overexpression of ephrin-B2 correlated with overexpression of EphB1 (r = 0.94, p < 0.05), EphB2 (r = 0.88, p < 0.01) and EphB4 (r = 0.76, p < 0.01). In alveolar tumours, no similar correlations were found. A correlation between EphB2 and EphB4 receptors was demonstrated in both tumour types, being positive in embryonal cases (r = 0.81, p < 0.01) and negative in alveolar (r = -1.00, p < 0.01).


CONCLUSIONS
A global up-regulation of ephrin-B and EphB receptors in RMS tumours was found. The correlation between EphB2 and EphB4 receptors suggests a possible role for ephrin-B and EphB receptors in RMS development.
Laboratory of Stem Cells, Bambino Gesù Children's Hospital, I-00165 Rome, Italy.
Anna C
AC
Berardi
Sonia
S
Marsilio
Cristina
C
Rofani
Ombretta
O
Salvucci
Pierluigi
P
Altavista
Francesco M
FM
Perla
Francesca
F
Diomedi-Camassei
Stefania
S
Uccini
George
G
Kokai
Lorena
L
Landuzzi
Heather P
HP
McDowell
Carlo
C
Dominici
D045744:Cell Line, Tumor; D036387:Ephrin-B1 / Q000378:metabolism; D036388:Ephrin-B2; D036342:Ephrins / Q000235:genetics*; D006801:Humans; D008024:Ligands; D012333:RNA, Messenger / Q000378:metabolism; D036081:Receptors, Eph Family / Q000235:genetics*; D012208:Rhabdomyosarcoma / Q000235:genetics*; D015854:Up-Regulation
C484288:EFNB1 protein, human; D036387:Ephrin-B1; D036388:Ephrin-B2; D036342:Ephrins; D008024:Ligands; D012333:RNA, Messenger; D036081:Receptors, Eph Family