title: Allelic loss of the active X chromosome during bladder carcinogenesis.
abstract: BACKGROUND
  Previous studies have shown that loss of the X chromosome is involved in the carcinogenesis of certain human malignancies.
  
  
  OBJECTIVE
  To determine whether X-linked allelic losses occur during bladder tumorigenesis and whether such losses involve the active or the inactive X chromosome.
  
  
  METHODS
  We analyzed the deletion status of the X-linked human androgen receptor gene locus in 6 female patients who underwent radical cystectomies for muscle-invasive urothelial carcinoma of the urinary bladder. Four patients had coexisting urothelial carcinoma in situ. Analysis for inactivation of the X chromosome was carried out in parallel.
  
  
  RESULTS
  Three cases were informative. Invasive tumor samples showed loss of heterozygosity involving the active allele at the androgen receptor locus in all 3 positive cases, whereas carcinoma in situ showed nonrandom X chromosome inactivation but not allelic deletion.
  
  
  CONCLUSIONS
  Our data suggest that allelic loss of the activated X chromosome is involved in bladder carcinogenesis and cancer progression.
authors.affiliation: Department of Pathology, Indiana University School of Medicine, Indianapolis, USA. lcheng@iupui.edu
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.forename: Gregory T
authors.initials: GT
authors.lastname: MacLennan
authors.forename: Chong-Xian
authors.initials: CX
authors.lastname: Pan
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Jones
authors.forename: Curtiss R
authors.initials: CR
authors.lastname: Moore
authors.forename: Shaobo
authors.initials: S
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Gu
authors.forename: Namrata B
authors.initials: NB
authors.lastname: Patel
authors.forename: Chinghai
authors.initials: C
authors.lastname: Kao
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Gardner
mesh_terms: D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D041321:Chromosomes, Human, X; D005260:Female; D006801:Humans; D019656:Loss of Heterozygosity; D011944:Receptors, Androgen / Q000235:genetics; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D011944:Receptors, Androgen