| Abstract: |
Purpose: There is increasing evidence for a fundamental role for epigenetic silencing of apoptotic pathways in cancer. Changes in DNA methylation can be detected with a high degree of sensitivity, so we used the MethyLight assay to determine how methylation patterns of apoptosis-associated genes change during bladder carcinogenesis and whether DNA methylation could be detected in urine sediments. Experimental Design: We analyzed the methylation status of the 5′ regions of 12 apoptosis-associated genes (ARF, FADD, TNFRSF21, BAX, LITAF, DAPK, TMS-1, BCL2, RASSF1A, TERT, TNFRSF25, and EDNRB) in 18 bladder cancer cell lines, 127 bladder cancer samples, and 37 samples of adjacent normal bladder mucosa using the quantitative MethyLight assay. We also analyzed the methylation status in urine sediments of 20 cancer-free volunteers and 37 bladder cancer patients. Results: The 5′ regions of DAPK, BCL2, TERT, RASSF1A, and TNFRSF25 showed significant increases in methylation levels when compared with nonmalignant adjacent tissue (P ≤ 0.01). Methylation levels of BCL2 were significantly associated with tumor staging and grading (P ≤ 0.01), whereas methylation levels of RASSF1A and ARF were only associated with tumor stage (P ≤ 0.04), and TERT methylation and EDNRB methylation were predictors of tumor grade (P ≤ 0.02). To investigate clinical usefulness for non-invasive bladder cancer detection, we further analyzed the methylation status of the markers in urine samples of patients with bladder cancer. Methylation of DAPK, BCL2, and TERT in urine sediment DNA from bladder cancer patients was detected in the majority of samples (78%), whereas they were unmethylated in the urine sediment DNA from age-matched cancer-free individuals. Conclusions: Our results indicate that methylation of the 5′ region of apoptosis-asscciated genes is a common finding in patients with bladder carcinoma. The ability to detect methylation not only in bladder tissue, but also in urine sediments, suggests that methylation markers are promising tools for noninvasive detection of bladder cancers. Our results also indicate that some methylation markers, such as those in regions of RASSF1A and TNFRSF25, might be of limited ose for detection because they are also methylated in normal bladder tissues. |
| Keywords: |
adult; clinical article; controlled study; aged; aged, 80 and over; middle aged; unclassified drug; human cell; case-control studies; cancer staging; cancer grading; genetic analysis; protein bcl 2; apoptosis; cancer cell culture; cell line, tumor; bladder cancer; telomerase; dna methylation; urinary bladder neoplasms; time factors; dna; tumor necrosis factor alpha; diagnostic value; reverse transcriptase polymerase chain reaction; cpg island; cpg islands; nucleotide sequence; death receptor 5; tumor suppressor proteins; urinary bladder; tumor necrosis factor receptor; gene silencing; dna primers; proto-oncogene proteins c-bcl-2; non invasive measurement; bladder carcinogenesis; protein p14; mucous membrane; collagen type 2; receptors, tumor necrosis factor; beta actin; protein bax; ras association domain family protein 1a; lipopolysaccharides; fas associated death domain protein; death associated protein kinase; humans; human; priority journal; article; death receptor 3; endothelin b receptor; lipopolysaccharide induced tumor necrosis factor alpha; urine sediment; receptors, tumor necrosis factor, member 25
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| Notes: |
Clin. Cancer Res. -- Cited By (since 1996):139 -- Export Date: 16 June 2014 -- CODEN: CCREF -- Molecular Sequence Numbers: GENBANK: AB051850, AF082338, AF325900, L10347, NM_000633, NM_003824, NM_003991, NM_004862, NM_007182, NM_013258, NM_014452, NM_138762, X76104; -- Source: Scopus |
