title: Carnitine palmitoyltransferase 1A (CPT1A): a transcriptional target of PAX3-FKHR and mediates PAX3-FKHR-dependent motility in alveolar rhabdomyosarcoma cells.
abstract: BACKGROUND
  Alveolar rhabdomyosarcoma (ARMS) has a high propensity to metastasize, leading to its aggressiveness and a poor survival rate among those with the disease. More than 80% of aggressive ARMSs harbor a PAX3-FKHR fusion transcription factor, which regulates cell migration and promotes metastasis, most likely by regulating the fusion protein's transcriptional targets. Therefore, identifying druggable transcription targets of PAX3-FKHR that are also downstream effectors of PAX3-FKHR-mediated cell migration and metastasis may lead to novel therapeutic approaches for treating ARMS.
  
  
  METHODS
  To identify genes whose expression is directly affected by the level of PAX3-FKHR in an ARMS cellular-context, we first developed an ARMS cell line in which PAX3-FKHR is stably down-regulated, and showed that stably downregulating PAX3-FKHR in ARMS cells significantly decreased the cells' motility. We used microarray analysis to identify genes whose expression level decreased when PAX3-FKHR was downregulated. We used mutational analysis, promoter reporter assays, and electrophoretic mobility shift assays to determine whether PAX3-FKHR binds to the promoter region of the target gene. We used siRNA and pharmacologic inhibitor to downregulate the target gene of PAX3-FKHR and investigated the effect of such downregulation on cell motility.
  
  
  RESULTS
  We found that when PAX3-FKHR was downregulated, the expression of carnitine palmitoyltransferase 1A (CPT1A) decreased. We showed that PAX3-FKHR binds to a paired-domain binding-site in the CPT1A promoter region, indicating that CPT1A is a novel transcriptional target of PAX3-FKHR. Furthermore, downregulating CPT1A decreased cell motility in ARMS cells, indicating that CPT1A is a downstream effector of PAX3-FKHR-mediated cell migration and metastasis.
  
  
  CONCLUSIONS
  Taken together, we have identified CPT1A as a novel transcriptional target of PAX3-FKHR and revealed the novel function of CPT1A in promoting cell motility. CPT1A may represent a novel therapeutic target for the treatment of ARMS.
authors.affiliation: Department of Chemical Biology and Therapeutics, St, Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: Lingling
authors.initials: L
authors.lastname: Liu
authors.forename: Yong-Dong
authors.initials: YD
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Jimmy
authors.initials: J
authors.lastname: Cui
authors.forename: Taosheng
authors.initials: T
authors.lastname: Chen
mesh_terms: D001665:Binding Sites; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D051761:Paired Box Transcription Factors / Q000378:metabolism; D020218:Response Elements; D018232:Rhabdomyosarcoma, Alveolar / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D015514:Oncogene Proteins, Fusion; C523321:PAX3-FKHR fusion protein, human; D051761:Paired Box Transcription Factors; C577474:CPT1A protein, human; D002334:Carnitine O-Palmitoyltransferase