title: Nuclear localization of the mitochondrial ncRNAs in normal and cancer cells.
abstract: BACKGROUND
  We have previously shown a differential expression of a family of mitochondrial ncRNAs in normal and cancer cells. Normal proliferating cells and cancer cells express the sense mitochondrial ncRNA (SncmtRNA). In addition, while normal proliferating cells express two antisense mitochondrial ncRNAs (ASncmtRNAs-1 and -2), these transcripts seem to be universally down-regulated in cancer cells. In situ hybridization (ISH) of some normal and cancer tissues reveals nuclear localization of these transcripts suggesting that they are exported from mitochondria.
  
  
  METHODS
  FISH and confocal microscopy, in situ digestion with RNase previous to ISH and electron microscopy ISH was employed to confirm the extra-mitochondrial localization of the SncmtRNA and the ASncmtRNAs in normal proliferating and cancer cells of human and mouse.
  
  
  RESULTS
  In normal human kidney and mouse testis the SncmtRNA and the ASncmtRNAs were found outside the organelle and especially localized in the nucleus associated to heterochromatin. In cancer cells, only the SncmtRNA was expressed and was found associated to heterochromatin and nucleoli.
  
  
  CONCLUSIONS
  The ubiquitous localization of these mitochondrial transcripts in the nucleus suggests that they are new players in the mitochondrial-nuclear communication pathway or retrograde signaling. Down regulation of the ASncmtRNAs seems to be an important step on neoplastic transformation and cancer progression.
authors.affiliation: Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Landerer
authors.forename: Jaime
authors.initials: J
authors.lastname: Villegas
authors.forename: Veronica A
authors.initials: VA
authors.lastname: Burzio
authors.forename: Luciana
authors.initials: L
authors.lastname: Oliveira
authors.forename: Claudio
authors.initials: C
authors.lastname: Villota
authors.forename: Constanza
authors.initials: C
authors.lastname: Lopez
authors.forename: Franko
authors.initials: F
authors.lastname: Restovic
authors.forename: Ronny
authors.initials: R
authors.lastname: Martinez
authors.forename: Octavio
authors.initials: O
authors.lastname: Castillo
authors.forename: Luis O
authors.initials: LO
authors.lastname: Burzio
mesh_terms: D000368:Aged; D000818:Animals; D001921:Brain / Q000378:metabolism / Q000648:ultrastructure; D002292:Carcinoma, Renal Cell / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D002467:Cell Nucleus / Q000235:genetics* / Q000648:ultrastructure; D015536:Down-Regulation; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000648:ultrastructure; D007680:Kidney Neoplasms / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008545:Melanoma / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D051379:Mice; D008928:Mitochondria / Q000235:genetics* / Q000648:ultrastructure; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure; D034443:RNA Transport; D016372:RNA, Antisense / Q000378:metabolism; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism*; D013737:Testis / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D016372:RNA, Antisense; D022661:RNA, Untranslated