Distinct DNA methylation epigenotypes in bladder cancer from different Chinese sub-populations and its implication in cancer detection using voided urine

<p>Abstract</p> <p>Background</p> <p>Bladder cancer is the sixth most common cancer in the world and the incidence is particularly high in southwestern Taiwan. Previous studies have identified several tumor-related genes that are hypermethylated in bladder cancer; however the DNA methylation profile of bladder cancer in Taiwan is not fully understood.</p> <p>Methods</p> <p>In this study, we compared the DNA methylation profile of multiple tumor suppressor genes (<it>APC</it>, <it>DAPK</it>, <it>E-cadherin</it>, <it>hMLH1</it>, <it>IRF8</it>, <it>p14</it>, <it>p15</it>, <it>RASSF1A</it>, <it>SFRP1 </it>and <it>SOCS-1</it>) in bladder cancer patients from different Chinese sub-populations including Taiwan (104 cases), Hong Kong (82 cases) and China (24 cases) by MSP. Two normal human urothelium were also included as control. To investigate the diagnostic potential of using DNA methylation in non-invasive detection of bladder cancer, degree of methylation of <it>DAPK</it>, <it>IRF8</it>, <it>p14</it>, <it>RASSF1A </it>and <it>SFRP1 </it>was also accessed by quantitative MSP in urine samples from thirty bladder cancer patients and nineteen non-cancer controls.</p> <p>Results</p> <p>There were distinct DNA methylation epigenotypes among the different sub-populations. Further, samples from Taiwan and China demonstrated a bimodal distribution suggesting that CpG island methylator phentotype (CIMP) is presented in bladder cancer. Moreover, the number of methylated genes in samples from Taiwan and Hong Kong were significantly correlated with histological grade (P < 0.01) and pathological stage (P < 0.01). Regarding the samples from Taiwan, methylation of <it>SFRP1</it>, <it>IRF8</it>, <it>APC </it>and <it>RASSF1A </it>were significantly associated with increased tumor grade, stage. Methylation of <it>RASSF1A </it>was associated with tumor recurrence. Patients with methylation of <it>APC </it>or <it>RASSF1A </it>were also significantly associated with shorter recurrence-free survival. For methylation detection in voided urine samples of cancer patients, the sensitivity and specificity of using any of the methylated genes (<it>IRF8</it>, <it>p14 </it>or <it>sFRP1</it>) by qMSP was 86.7% and 94.7%.</p> <p>Conclusions</p> <p>Our results indicate that there are distinct methylation epigenotypes among different Chinese sub-populations. These profiles demonstrate gradual increases with cancer progression. Finally, detection of gene methylation in voided urine with these distinct DNA methylation markers is more sensitive than urine cytology.</p

DNA methylation patterns in bladder cancer and washing cell sediments: a perspective for tumor recurrence detection

<p>Abstract</p> <p>Background</p> <p>Epigenetic alterations are a hallmark of human cancer. In this study, we aimed to investigate whether aberrant DNA methylation of cancer-associated genes is related to urinary bladder cancer recurrence.</p> <p>Methods</p> <p>A set of 4 genes, including <it>CDH1 </it>(E-cadherin), <it>SFN </it>(stratifin), <it>RARB </it>(retinoic acid receptor, beta) and <it>RASSF1A </it>(Ras association (RalGDS/AF-6) domain family 1), had their methylation patterns evaluated by MSP (Methylation-Specific Polymerase Chain Reaction) analysis in 49 fresh urinary bladder carcinoma tissues (including 14 cases paired with adjacent normal bladder epithelium, 3 squamous cell carcinomas and 2 adenocarcinomas) and 24 cell sediment samples from bladder washings of patients classified as cancer-free by cytological analysis (control group). A third set of samples included 39 archived tumor fragments and 23 matched washouts from 20 urinary bladder cancer patients in post-surgical monitoring. After genomic DNA isolation and sodium bisulfite modification, methylation patterns were determined and correlated with standard clinic-histopathological parameters.</p> <p>Results</p> <p><it>CDH1 </it>and <it>SFN </it>genes were methylated at high frequencies in bladder cancer as well as in paired normal adjacent tissue and exfoliated cells from cancer-free patients. Although no statistically significant differences were found between <it>RARB </it>and <it>RASSF1A </it>methylation and the clinical and histopathological parameters in bladder cancer, a sensitivity of 95% and a specificity of 71% were observed for <it>RARB </it>methylation (Fisher's Exact test (p < 0.0001; OR = 48.89) and, 58% and 17% (p < 0.05; OR = 0.29) for <it>RASSF1A </it>gene, respectively, in relation to the control group.</p> <p>Conclusion</p> <p>Indistinct DNA hypermethylation of <it>CDH1 </it>and <it>SFN </it>genes between tumoral and normal urinary bladder samples suggests that these epigenetic features are not suitable biomarkers for urinary bladder cancer. However, <it>RARB </it>and <it>RASSF1A </it>gene methylation appears to be an initial event in urinary bladder carcinogenesis and should be considered as defining a panel of differentially methylated genes in this neoplasia in order to maximize the diagnostic coverage of epigenetic markers, especially in studies aiming at early recurrence detection.</p

Low VHL mRNA Expression is Associated with More Aggressive Tumor Features of Papillary Thyroid Carcinoma

Alterations of the von Hippel-Lindau (VHL) tumor suppressor gene can cause different hereditary tumors associated with VHL syndrome, but the potential role of the VHL gene in papillary thyroid carcinoma (PTC) has not been characterized. This study set out to investigate the relationship of VHL expression level with clinicopathological features of PTC in an ethnically and geographically homogenous group of 264 patients from Serbia, for the first time. Multivariate logistic regression analysis showed a strong correlation between low level of VHL expression and advanced clinical stage (OR55.78, 95% CI 3.17-10.53, P<0.0001), classical papillary morphology of the tumor (OR52.92, 95% CI 1.33-6.44, P=50.008) and multifocality (OR51.96, 95% CI 1.06-3.62, P=50.031). In disease-free survival analysis, low VHL expression had marginal significance (P=50.0502 by the log-rank test) but did not appear to be an independent predictor of the risk for chance of faster recurrence in a proportion hazards model. No somatic mutations or evidence of VHL downregulation via promoter hypermethylation in PTC were found. The results indicate that the decrease of VHL expression associates with tumor progression but the mechanism of downregulation remains to be elucidated

Briefing: UK-RAS white paper in robotics and autonomous systems for resilient infrastructure

This paper presents an extended briefing of the recently published UK-Robotics and autonomous systems (RAS) network Whie Paper in RAS for resilient infrastructure. It aims at setting out a vision of what RAS systems will be able to deliver in infrastructure, what are the current barriers and challenges to achieve that vision and what can the UK Government do to ensure that the UK remains at the forefront in this field