الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Introduction: Carcinogenesis is a stepwise process of accumulation of genetic and epigenetic abnormalities that can lead to cellular dysfunction. Methylation of CpG sites in the genome, which is generally conserved during cell replication, is considered to play important roles in cell differentiation and carcinogenesis. DNA methylation is believed to be an on-off switch in gene expression. Changes in the methylation profile of the promoters represent an alternative to genetic lesions as causative factors for the tumor-specific aberrant expression of the genes. Conclusions: 1-Because of the significant changes in expression of cyclin D1, cyclin E and TERT during urinary bladder carcinogenesis, they could become useful biomarkers to identify precancerous lesions in the early stage of urinary bladder cancer. 2-Multiple stepwise progressive changes in methylation patterns are observed during EBN induced rat urinary bladder carcinogenesis. These methylation alterations appear to be important in tumor promotion and provide further support for the multiple roles that aberrant methylation may play in this process. These methylation changes occur early during oncogenesis and are detectable prior to the appearance of clinically evident tumor. 3-Overexpression of cyclin D1 and cyclin E and expression of TERT may be related to the methylation changes observed during cancer bladder development.