Allelic loss of the active X chromosome during bladder carcinogenesis.
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.
Cheng
Liang
L
Department of Pathology, Indiana University School of Medicine, Indianapolis, USA. lcheng@iupui.edu
MacLennan
Gregory T
GT
Pan
Chong-Xian
CX
Jones
Timothy D
TD
Moore
Curtiss R
CR
Zhang
Shaobo
S
Gu
Jian
J
Patel
Namrata B
NB
Kao
Chinghai
C
Gardner
Thomas A
TA
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
D011944:Receptors, Androgen