Validation of met as a therapeutic target in alveolar and embryonal rhabdomyosarcoma.
Rhabdomyosarcoma (RMS) is a highly malignant soft-tissue tumor of childhood deriving from skeletal muscle cells. RMS can be classified in two major histologic subtypes: embryonal (ERMS) and alveolar (ARMS), the latter being characterized by the PAX3/7-FKHR translocation. Here we first investigated whether the Met receptor, a transcriptional target of PAX3 and PAX7, has a role in PAX3-FKHR-mediated transformation. Following PAX3-FKHR transduction, Met was up-regulated in mouse embryonal fibroblasts (MEF), NIH 3T3 and C2C12 cells, and they all acquired anchorage independence. This property was lost in low serum but addition of hepatocyte growth factor/scatter factor (HGF/SF) rescued soft-agar growth. Genetic proof that Met is necessary for this PAX3-FKHR-mediated effect was obtained by transducing with PAX3-FKHR MEFs derived from Met mutant (Met(D/D)) and wild-type (Met(+/+)) embryos. Only Met(+/+) MEFs acquired anchorage-independent growth whereas PAX3-FKHR-transduced Met(D/D) cells were unable to form colonies in soft agar. To verify if Met had a role in RMS maintenance, we silenced the receptor by transducing ERMS and ARMS cell lines with an inducible lentivirus expressing an anti-Met short hairpin RNA (shRNA). Met down-regulation significantly affected RMS cells proliferation, survival, invasiveness, and anchorage-independent growth. Finally, induction of the Met-directed shRNA promoted a dramatic reduction of tumor mass in a xenograft model of RMS. Our data show that both ARMS- and ERMS-derived cell lines, in spite of the genetic drift which may have occurred in years of culture, seem to have retained an "addiction" to the Met oncogene and suggest that Met may represent a target of choice to develop novel therapeutic strategies for ARMS.
Taulli
Riccardo
R
Center for Experimental Research and Medical Studies (CERMS), University of Turin, Turin, Italy.
Scuoppo
Claudio
C
Bersani
Francesca
F
Accornero
Paolo
P
Forni
Paolo E
PE
Miretti
Silvia
S
Grinza
Alberto
A
Allegra
Paola
P
Schmitt-Ney
Michel
M
Crepaldi
Tiziana
T
Ponzetto
Carola
C
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D048708:Cell Growth Processes / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000473:pathology; D005260:Female; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000235:genetics; D020868:Gene Silencing; D006367:HeLa Cells; D017228:Hepatocyte Growth Factor; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D041681:NIH 3T3 Cells; D009361:Neoplasm Invasiveness; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000502:physiology*; D019859:Proto-Oncogene Proteins c-met; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000235:genetics; D017978:Receptors, Growth Factor / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000502:physiology*; D018232:Rhabdomyosarcoma, Alveolar / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D018233:Rhabdomyosarcoma, Embryonal / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D014161:Transduction, Genetic; D015854:Up-Regulation
C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D015514:Oncogene Proteins, Fusion; D000072041:PAX3 Transcription Factor; C489409:PAX3 protein, human; D051761:Paired Box Transcription Factors; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D017978:Receptors, Growth Factor; D017228:Hepatocyte Growth Factor; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met