Hypermethylation of an E-cadherin (CDH1) promoter region in high grade transitional cell carcinoma of the bladder comprising carcinoma in situ.
OBJECTIVE
We elucidated the role of methylation in the promoter region of the 1 gene in bladder carcinogenesis, particularly in those comprising carcinoma in situ.


METHODS
A total of 49 cases of transitional cell carcinoma of the bladder obtained from transurethral resection were examined. Methylation status of the 1 promoter region was analyzed by methylation specific polymerase chain reaction from chemically modified DNA after Na-bisulfite treatment. Loss of heterozygosity on 16q was examined by blunt end single strand DNA conformation polymorphism using 4 tetranucleotide repeat microsatellite markers assigned on 16q13 to 22.1. E-cadherin expression was evaluated by immunostaining on formalin fixed, paraffin embedded tissue sections using anti E-cadherin murine monoclonal antibody, HECD1 and standard avidin-biotin immunoperoxidase complex technique.


RESULTS
Analysis of the 49 bladder transitional cell carcinoma samples showed 1 promoter methylation in 23 (47%). Methylation of the 1 gene did not correlate with tumor stage (p = 0.2097) but with high grade transitional cell carcinoma (p = 0.0416). 1 promoter methylation was observed at a significantly higher frequency in the carcinoma in situ positive group than in the carcinoma in situ negative group (16 of 18 cases or 89% versus 7 of 31 or 23%, p <0.0001) and it strongly correlated with abnormal E-cadherin expression (p <0.0001). We found 16q loss of heterozygosity in 16 of 47 cases (34%), which correlated with higher histological grade (p = 0.0069) but not with the presence of the carcinoma in situ component (p = 0.1235).


CONCLUSIONS
This study showed that 1 gene promoter methylation is strongly associated with bladder transitional cell carcinoma comprising carcinoma in situ.
Horikawa
Yohei
Y
Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute and Department of Urology, Tochigi Cancer Hospital, Japan.
Sugano
Kokichi
K
Shigyo
Masanori
M
Yamamoto
Hidenobu
H
Nakazono
Masaaki
M
Fujimoto
Hiroyuki
H
Kanai
Yae
Y
Hirohashi
Setsuo
S
Kakizoe
Tadao
T
Habuchi
Tomonori
T
Kato
Tetsuro
T
D000483:Alleles; D015703:Antigens, CD; D015820:Cadherins / Q000235:genetics*; D002278:Carcinoma in Situ / Q000235:genetics* / Q000473:pathology; D002295:Carcinoma, Transitional Cell / Q000235:genetics* / Q000473:pathology; D002885:Chromosomes, Human, Pair 16; D019175:DNA Methylation; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D020868:Gene Silencing / Q000502:physiology; D006801:Humans; D019656:Loss of Heterozygosity; D011401:Promoter Regions, Genetic; D001743:Urinary Bladder / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology
D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins