Next, hmDNA levels (RASSF1A qMSP) in stored urine samples of patients suffering from bladder cancer (n = 10) or non-small cell lung cancer (NSCLC; n = 10) were measured at day 0 and 7 upon storage with and without the addition of 40mM EDTA and/or 20 μl/ml Penicillin Streptomycin (PenStrep) at RT and 4°C.
Promoter hypermethylation occurred frequently in both pathologically normal urothelium and tumor samples from bladder cancer patients, and increased with progression from normal to bladder cancer at E-cadherin (P = 0.067), p16 (P < 0.001), p14 (P = 0.01), and RASSF1A (P = 0.01).
Methylation-specific PCR (MSP) assay was used to detect promoter hypermethylation in 4 genes (E-cadherin, p16, p14, and RASSF1A) to identify reliable biomarkers for bladder cancer diagnosis in primary tumor DNA and urine sediment DNA from 57 bladder cancer patients.
There was no association between MTHFR gene variants and methylation status of the RASSF1A gene in the 45 bladder cancer patients in whom this was studied.
Although no statistically significant differences were found between RARB and RASSF1A methylation and the clinical and histopathological parameters in bladder cancer, a sensitivity of 95% and a specificity of 71% were observed for RARB methylation (Fisher's Exact test (p < 0.0001; OR = 48.89) and, 58% and 17% (p < 0.05; OR = 0.29) for RASSF1A gene, respectively, in relation to the control group.
Moreover, both tumors exhibited an identical mutation in p53, as well as similar loss of heterozygosity at 10q23 and RASSF1A promoter hypermethylation, clearly indicating that the bladder tumor was the site for the primary tumor of the patient.
Promoter hypermethylation in p16, RARbeta, RASSF1A, DAPK, and MGMT genes was analyzed in 58 cases with superficial bladder cancer and 2 cases with benign urological disease using methylation-specific PCR.
We, therefore, examined, in a population-based study of human bladder cancer, the relationship between epigenetic silencing of three tumor suppressor genes, p16(INK4A), RASSF1A and PRSS3, and exposure to both tobacco and arsenic in bladder cancer.
We, therefore, examined, in a population-based study of human bladder cancer, the relationship between epigenetic silencing of three tumor suppressor genes, p16(INK4A), RASSF1A and PRSS3, and exposure to both tobacco and arsenic in bladder cancer.
We, therefore, examined, in a population-based study of human bladder cancer, the relationship between epigenetic silencing of three tumor suppressor genes, p16(INK4A), RASSF1A and PRSS3, and exposure to both tobacco and arsenic in bladder cancer.
We, therefore, examined, in a population-based study of human bladder cancer (n = 351), the relationship between epigenetic silencing of the tumor-suppressor genes, p16(INK4A), RASSF1A, PRSS3, and the four SFRP genes and exposure to both tobacco and arsenic in bladder cancer.
A quantitative fluorogenic real-time polymerase chain reaction (PCR) assay was used to examine primary tumor DNA and urine sediment DNA from 15 patients with bladder cancer and 25 control subjects for promoter hypermethylation of nine genes (APC, ARF, CDH1, GSTP1, MGMT, CDKN2A, RARbeta2, RASSF1A, and TIMP3) to identify potential biomarkers for bladder cancer.
Although somatic mutations were not identified in RASSF1 transcripts expressed in unmethylated tumors, 24% (9 of 37) of methylated cell lines and primary tumors showed detectable reductions in genomic levels of RASSF1, suggesting that RASSF1A inactivation might be caused by both epigenetic and genetic mechanisms in a subset of bladder tumors.