title: The role of RASSF1A in uveal melanoma.
abstract: OBJECTIVE
  RASSF1A inactivation in uveal melanoma (UM) is common and methylation-induced. We investigated the effect of RASSF1A re-expression on the UM phenotype in vivo and in vitro.
  
  
  METHODS
  The phenotypic effect of methylation-induced inactivation of RASSF1A in UM was explored using a stable RASSF1A-expressing UM-15 clone. RASSF1A expression was assessed using QRT-PCR. Proliferation was evaluated in vitro using MTT assays. Additionally, athymic NOD/SCID mice were injected subcutaneously or intraocularly with RASSF1A-expressing and -non-expressing UM-15 clones, and euthanized when tumors reached a volume of 1500 mm(3), or at 56 or 46 days, respectively. Tumor tissues, eyes, and livers were analyzed histologically.
  
  
  RESULTS
  In vitro analysis confirmed the lack of RASSF1A expression and full methylation of the RASSF1A promoter region in the UM-15 cell line, which was reversible following treatment with 5-Aza-2-deoxycytidine. Cells expressing exogenous RASSF1A showed slower proliferation than controls and regained sensitivity to cisplatin. Compared to mice injected with control cells, mice treated with UM-15 cells expressing exogenous RASSF1A did not acquire intraocular tumors, and their subcutaneous tumors were relatively delayed and small. Neither group had liver metastases.
  
  
  CONCLUSIONS
  UM cells reduced tumorigenicity in the presence of activated RASSF1A. RASSF1A apparently has an important role in the development of UM, and its reactivation might be applied in the development of new treatments.
authors.affiliation: Krieger Eye Research Laboratory, Felsenstein Medical Research Center, Petah Tiqwa. Israel.
authors.forename: Olga
authors.initials: O
authors.lastname: Dratviman-Storobinsky
authors.forename: Yoram
authors.initials: Y
authors.lastname: Cohen
authors.forename: Shahar
authors.initials: S
authors.lastname: Frenkel
authors.forename: Efrat
authors.initials: E
authors.lastname: Merhavi-Shoham
authors.forename: Shimrit Dadon-Bar
authors.initials: SD
authors.lastname: El
authors.forename: Natalia
authors.initials: N
authors.lastname: Binkovsky
authors.forename: Jacob
authors.initials: J
authors.lastname: Pe'er
authors.forename: Nitza
authors.initials: N
authors.lastname: Goldenberg-Cohen
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D002945:Cisplatin / Q000633:toxicity; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D020868:Gene Silencing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008545:Melanoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D016688:Mice, Inbred NOD; D008819:Mice, Nude; D016513:Mice, SCID; D009006:Monosomy / Q000235:genetics; D009368:Neoplasm Transplantation; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism; D014604:Uveal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; C411762:RASSF1 protein, human; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; D002945:Cisplatin