Cancer-testis antigen expression in bladder cancer

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Cancer-testis antigens (CTAs) are typically expressed in germ cells but aberrantly expressed in various cancers, making them potential targets for cancer immunotherapy.
• Epigenetic mechanisms, such as DNA methylation and histone modification, play a crucial role in regulating CTA expression.

Purpose of the Study:

• To investigate the expression of nine CTA genes/families in normal urothelia, bladder tumors, and bladder cancer cell lines.
• To assess the impact of epigenetic modifiers, specifically 5-aza-2 -deoxycytidine (5-AZA-DC) and Trichostatin A (TSA), on CTA expression in bladder cancer cell lines.

Main Methods:

• Semi-quantitative RT-PCR and Western blotting were employed to analyze CTA expression.
• Expression analysis was performed on 10 normal urothelia, 45 superficial and invasive bladder tumors, and 10 bladder cancer cell lines.
• Bladder cancer cell lines were treated with 5-AZA-DC and/or TSA to evaluate their effect on CTA expression.

Main Results:

• CTA gene expression was detected in at least one tumor, with HOM-TES-85 being the exception.
• MAGE-A, BAGE, and NY-ESO-1/LAGE-1 were the most frequently detected CTAs in bladder tumors.
• While CTA transcripts were rarely found in untreated cell lines, 5-AZA-DC and TSA treatment induced expression of most CTAs, with 5-AZA-DC being more potent.

Conclusions:

• CTAs, particularly MAGE-A, BAGE, and NY-ESO-1/LAGE-1, are potential targets for bladder cancer immunotherapy.
• The induction of CTA expression by chemotherapeutic agents like 5-AZA-DC offers a strategy for enhancing tumor immunogenicity prior to treatment.