Effects of Tumor Necrosis Factor-α (TNFα) and Interferon-γ (IFNγ) on Gene Expression Profiles in Bladder Carcinoma Cells Using Oligonucleotide Microarray Analysis.

Background: TNFα and IFNγ, two main cytokines secreted in the urine of bladder cancer patients after Bacillus Calmette Guerin immunotherapy (BCG therapy), exert various responses ranging from growth arrest, apoptosis, phenotypic changes and differentiation.

Materials And Methods: To identify their transcriptional and translational targets, the highly sensitive bladder cancer cell line (RT112) was treated for 24 hours with increasing doses of IFNγ or TNFα and analyzed for cellular and molecular changes using a cDNA microarray technique (Transcriptome) containing 800 genes.

Results: High doses (>10 ng/ml) induced an apoptotic cell death, whereas low doses (<5 ng/ml) induced a survival program. TNFα-inducible genes, IFNγ-inducible genes and genes modulated by TNFα and IFNγ together were identified. All were related to the tumor progression program including cell proliferation, apoptosis/survival, angiogenesis and metastatic processes.

Conclusion: These results suggest that the transcriptomic approach could be a good methodology to determine the molecular mechanisms involved in bladder tumor progression processes in relation to a low response to BCG treatment. However, mRNA and protein expression did not always correlate, suggesting that translational regulation is a vital process in bladder tumor progression.