title: Expression and function of a large non-coding RNA gene XIST in human cancer.
abstract: BACKGROUND
  X inactive-specific transcript (XIST) RNA is involved in X chromosome silencing in female cells and allows X chromosome equilibration with males. X inactive-specific transcript expression has been found to be dysregulated in a variety of human cancers when compared to normal cells; meanwhile, the inactivated X chromosome has been noted to be conspicuously absent in human cancer specimens, whereas X chromosome duplications are widely noted. The specific pathways whereby changes in X chromosome status and XIST expression occur in cancer remain incompletely described. Nevertheless, a role for XIST in BRCA1-mediated epigenetic activity has been proposed.
  
  
  METHODS
  Here we review the data regarding XIST expression and X chromosome status in a variety of female, male, and non-sex-related human cancers.
  
  
  CONCLUSIONS
  It is not yet known whether X chromosome duplication, XIST dysregulation, and over-expression of X-linked genes represent important factors in tumorgenesis or are simply a consequence of overall epigenetic instability in these cancers.
authors.affiliation: Molecular Surgeon Research Center, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Mail stop: BCM391, Houston, TX 77030, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Weakley
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Qizhi
authors.initials: Q
authors.lastname: Yao
authors.forename: Changyi
authors.initials: C
authors.lastname: Chen
mesh_terms: D000818:Animals; D019313:BRCA1 Protein / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics; D044127:Epigenesis, Genetic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D020868:Gene Silencing; D006801:Humans; D007713:Klinefelter Syndrome / Q000235:genetics; D008297:Male; D051379:Mice; D009369:Neoplasms / Q000235:genetics*; D009373:Neoplasms, Germ Cell and Embryonal / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics; D057285:Precision Medicine / Q000639:trends*; D011471:Prostatic Neoplasms / Q000235:genetics; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics*; D013736:Testicular Neoplasms / Q000235:genetics; D002583:Uterine Cervical Neoplasms / Q000235:genetics
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; C077885:XIST non-coding RNA