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Eur Urol. 2010 Jul;58(1):96-104. doi: 10.1016/j.eururo.2009.07.041. Epub 2009 Aug 5.

Identification and validation of the methylated TWIST1 and NID2 genes through real-time methylation-specific polymerase chain reaction assays for the noninvasive detection of primary bladder cancer in urine samples.

Author information

1
OncoMethylome Sciences SA, Liège, Belgium.

Abstract

BACKGROUND:

Accumulating evidence suggests that DNA methylation markers could serve as sensitive and specific cancer biomarkers.

OBJECTIVE:

To determine whether a panel of methylated genes would have the potential to identify primary bladder cancer (BCa) in voided urine samples.

DESIGN, SETTING, AND PARTICIPANTS:

A pharmacologic unmasking reexpression analysis in BCa cell lines was initially undertaken to unveil candidate methylated genes, which were then evaluated in methylation-specific polymerase chain reaction (MSP) assays performed on DNA extracted from noncancerous and cancerous bladder tissues. The most frequently methylated genes in cancerous tissues, with 100% specificity, were retained for subsequent MSP analysis in DNA extracted from urine samples to build and validate a panel of potential methylated gene markers. Urine samples were prospectively collected at three urologic centres from patients with histologically proven BCa and processed for use in real-time MSP and cytologic analysis. Patients with nonmalignant urologic disorders were included as controls.

MEASUREMENTS:

A urine sample was classified as valid when > or = 10 copies of the gene encoding ß-actin were measured in the urine sediment genomic DNA. Sensitivity, specificity, and predictive values of the MSP and cytology tests were assessed and compared.

RESULTS AND LIMITATIONS:

MSP assays performed on 466 of the 496 (94%) valid urine samples identified two genes, TWIST1 and NID2, that were frequently methylated in urine samples collected from BCa patients, including those with early-stage and low-grade disease. The sensitivity of this two-gene panel (90%) was significantly better than that of cytology (48%), with comparable specificity (93% and 96%, respectively). The positive predictive value and negative predictive value of the two-gene panel was 86% and 95%, respectively.

CONCLUSIONS:

Detection of the methylated TWIST1 and NID2 genes in urine sediments using MSP provides a highly (> or = 90%) sensitive and specific, noninvasive approach for detecting primary BCa.

TRIAL REGISTRATION:

BlCa-001 study - EudraCt 2006-003303-40.

PMID:
19674832
DOI:
10.1016/j.eururo.2009.07.041
[Indexed for MEDLINE]

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