title: EMT-associated factors promote invasive properties of uveal melanoma cells.
abstract: OBJECTIVE
  Transcription factors regulating the epithelial-to-mesenchymal transition (EMT) program contribute to carcinogenesis and metastasis in many tumors, including cutaneous melanoma. However, little is known about the role of EMT factors in the growth and metastatic dissemination of uveal melanoma cells. Here, we analyzed the expression and functions of the EMT factors ZEB1, Twist1, and Snail1 in uveal melanoma cell lines and primary tumors.
  
  
  METHODS
  ZEB1, Twist1, and Snail1 mRNA levels were measured using qPCR in five uveal melanoma cell lines and in 30 primary tumors. Gene expression was used to determine class 1 and class 2 signatures in the primary tumors. Short hairpin RNA was used to downregulate the expressions of the EMT factors; then, growth and transwell invasion assays were performed.
  
  
  RESULTS
  ZEB1, Twist1, and Snail1 were expressed in all five uveal melanoma lines, with ZEB1 having the highest protein levels. ZEB1 mRNA was significantly elevated in highly metastatic class 2 primary tumors for which survival data were not available, whereas a high gene expression of Twist1 was associated with a worse prognosis in a separate tumor cohort analyzed by expression profiling. The genetic downregulation of ZEB1 in OCM1, OMM1, and 92.1 resulted in a more than 50% reduction in invasion, but only suppressed growth in OMM1 cells. Suppression of Twist1 in Mel290 and OMM1 reduced growth and invasion by more than 50%. The downregulation of Snail1 in the 92.1 cell line reduced invasion by 50%, but did not interfere with growth.
  
  
  CONCLUSIONS
  The downregulation of ZEB1, Twist1, and Snail1 reduces the invasive properties of uveal melanoma cells, and the elevated mRNA levels of ZEB1 and Twist1 are associated with a more aggressive clinical phenotype in uveal melanoma samples. Therefore, these factors could represent new therapeutic targets in patients with ocular melanoma.
authors: Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD.
authors: Laura
authors: L
authors: Asnaghi
authors: Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Gülçin
authors: G
authors: Gezgin
authors: Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD.
authors: Arushi
authors: A
authors: Tripathy
authors: Department of Ophthalmology, Johns Hopkins University, School of Medicine, Baltimore, MD.
authors: James T
authors: JT
authors: Handa
authors: Department of Ophthalmology, Johns Hopkins University, School of Medicine, Baltimore, MD ; Department of Oncology, Johns Hopkins University, School of Medicine, Baltimore, MD.
authors: Shannath L
authors: SL
authors: Merbs
authors: Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Pieter A
authors: PA
authors: van der Velden
authors: Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Martine J
authors: MJ
authors: Jager
authors: Ocular Oncology, Bascom Palmer Eye Institute and Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL.
authors: J William
authors: JW
authors: Harbour
authors: Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD ; Department of Ophthalmology, Johns Hopkins University, School of Medicine, Baltimore, MD ; Department of Oncology, Johns Hopkins University, School of Medicine, Baltimore, MD.
authors: Charles G
authors: CG
authors: Eberhart
mesh_terms: D045744:Cell Line, Tumor; D015536:Down-Regulation; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics* / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008545:Melanoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000503:physiopathology; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D051879:Twist-Related Protein 1 / Q000235:genetics* / Q000378:metabolism*; D014604:Uveal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D000071799:Zinc Finger E-box-Binding Homeobox 1; D000098943:Uveal Melanoma
chemical_list: D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D034741:RNA, Small Interfering; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; C103173:TWIST1 protein, human; D014157:Transcription Factors; D051879:Twist-Related Protein 1; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1