Inhibition of platelet-derived growth factor-induced cell growth signaling by a short interfering RNA for EWS-Fli1 via down-regulation of phospholipase D2 in Ewing sarcoma cells.
EWS-Fli1, a fusion gene resulting from a chromosomal translocation t(11;22, q24;q12) and found in Ewing sarcoma and primitive neuroectodermal tumors, encodes a transcriptional activator and promotes cellular transformation. However, the precise biological functions of its products remain unknown. To investigate the role of EWS-Fli1 in cell growth signaling, we transfected Ewing sarcoma TC-135 cells with short interfering RNAs for EWS-Fli1. EWS-Fli1 knockdown reduced cell growth and platelet-derived growth factor (PDGF)-BB-induced activation of the growth signaling enzymes. Interestingly, phospholipase D2 (but not the PDGF-BB receptor) showed marked down-regulation in the EWS-Fli1-knocked down TC-135 cells compared with the control cells. In Ewing sarcoma TC-135 cells, the PDGF-BB-induced phosphorylation of growth signaling involving extracellular signal-regulated kinase, Akt, p70S6K, and the expression of cyclin D3 were markedly inhibited by transfection with short interfering RNA phospholipase (PL)-D2. The PDGF-BB-induced activation of growth signaling was also suppressed by 1-butanol, which prevents the production of phosphatidic acid by phospholipase D (but not by t-butyl alcohol), thereby implicating PLD2 in PDGF-BB-mediated signaling in TC-135 cells. These results suggest that EWS-Fli1 may play a role in the regulation of tumor proliferation-signaling enzymes via PLD2 expression in Ewing sarcoma cells.
Nozawa
Satoshi
S
Department of Orthopaedic Surgery, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Ohno
Takatoshi
T
Banno
Yoshiko
Y
Dohjima
Taikoh
T
Wakahara
Kazuhiko
K
Fan
De-Gang
DG
Shimizu
Katsuji
K
D000077214:Becaplermin; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D056743:Cyclin D3; D016213:Cyclins / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008954:Models, Biological; D015514:Oncogene Proteins, Fusion / Q000235:genetics* / Q000378:metabolism*; D010739:Phospholipase D / Q000096:biosynthesis*; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051789:Proto-Oncogene Protein c-fli-1; D020574:Proto-Oncogene Proteins c-sis; D034741:RNA, Small Interfering / Q000378:metabolism*; D034802:RNA-Binding Protein EWS; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D012512:Sarcoma, Ewing / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection
C534696:CCND3 protein, human; D056743:Cyclin D3; D016213:Cyclins; C106031:EWS-FLI fusion protein; D004791:Enzyme Inhibitors; D015514:Oncogene Proteins, Fusion; D010982:Platelet-Derived Growth Factor; D051789:Proto-Oncogene Protein c-fli-1; D020574:Proto-Oncogene Proteins c-sis; D034741:RNA, Small Interfering; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors; D000077214:Becaplermin; D038762:Ribosomal Protein S6 Kinases, 70-kDa; C105606:phospholipase D2; D010739:Phospholipase D