Hypermethylation of multiple genes in tumor tissues and voided urine in urinary bladder cancer patients.
OBJECTIVE
We aimed to investigate the methylation pattern in bladder cancer and assess the diagnostic potential of such epigenetic changes in urine.


METHODS
The methylation status of 7 genes (RARbeta, DAPK, E-cadherin, p16, p15, GSTP1, and MGMT) in 98 cases of bladder transitional cell carcinoma and 4 cases of carcinoma in situ was analyzed by methylation-specific PCR. Twenty-two cases had paired voided urine samples for analysis.


RESULTS
In transitional cell carcinoma tumor tissues, aberrant methylation was frequently detected in RARbeta (87.8%), DAPK (58.2%), E-cadherin (63.3%), and p16 (26.5%), whereas methylation of p15 (13.3%), GSTP1 (5.1%), and MGMT (5.1%) is not common. No association between methylation status and grading or muscle invasiveness was demonstrated. In 22 paired voided urine samples of bladder cancer, methylation of DAPK, RARbeta, E-cadherin, and p16 could be detected in 45.5%, 68.2%, 59.1%, and 13.6% of the cases, respectively. The sensitivity of methylation analysis (90.9%) was higher than that of urine cytology (45.5%) for cancer detection. Methylation of RARbeta(50%), DAPK (75%), and E-cadherin (50%) was also detected in carcinoma in situ. In 7 normal urothelium samples and 17 normal urine controls, no aberrant methylation was detected except for RARbeta methylation in 3 normal urothelium samples (42.9%) and 4 normal urine samples (23.5%), respectively.


CONCLUSIONS
Our results demonstrated a distinct methylation pattern in bladder cancer with frequent methylation of RARbeta, DAPK, E-cadherin, and p16. Detection of gene methylation in routine voided urine using selected markers appeared to be more sensitive than conventional urine cytology.
Chan
Michael W Y
MW
Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, People's Republic of China.
Chan
Lun W
LW
Tang
Nelson L S
NL
Tong
Joanna H M
JH
Lo
Kwok W
KW
Lee
Tin L
TL
Cheung
Ho Y
HY
Wong
Wai S
WS
Chan
Peter S F
PS
Lai
Fernand M M
FM
To
Ka F
KF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051017:Apoptosis Regulatory Proteins; D015820:Cadherins / Q000235:genetics / Q000378:metabolism / Q000652:urine; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism / Q000652:urine; D002295:Carcinoma, Transitional Cell / Q000235:genetics* / Q000378:metabolism / Q000652:urine*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D019175:DNA Methylation; D064550:Death-Associated Protein Kinases; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000652:urine*
D051017:Apoptosis Regulatory Proteins; D015820:Cadherins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases