The expression levels of miR-194-5p and E2F transcription factor 3 (E2F3) were determined by means of quantitative reverse transcription and polymerase chain reaction in BC specimens.
In summary, our data indicate that E2F3 is a key regulator of cell proliferation in a subset of bladder cancer and the 6p22.3 amplicon is a biomarker of aggressive phenotype in this tumor type.
The E2F3 mRNA and protein expression levels were detected in bladder cancer tissues and cell lines, and interestingly, inverse correlations between miR-125b and E2F3 protein level were found in bladder cancer tissues and four E2F3 nonamplified cell lines.
Amplification of E2F3 and NM_017774 was analysed by fluorescence in situ hybridization on a bladder cancer tissue microarray composed of 2317 cancer samples.
In previous studies we have provided evidence that nuclear E2F3 overexpression represents a mechanism that drives the development of human bladder cancer and that determines aggressiveness in human prostate cancer.
To further investigate the role of E2F3 in bladder cancer, a tissue microarray containing samples from 2317 bladder tumors was used for gene copy number and expression analysis by means of fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC).
When considered together with the established role of E2F3 in cell cycle progression, these results suggest that the E2F3 gene represents a candidate bladder cancer oncogene that is activated by DNA amplification and overexpression.