Cancer-testis antigen expression in bladder cancer.
OBJECTIVE
To evaluate the potential of cCancer-t/Testis antigens (CTAs) as targets for immunotherapy of bladder cancer, we evaluated the expression of 9 CTA genes or families of genes in normal urothelia, bladder tumours and bladder cancer human bladder tissuescell lines. As expression of most CTAs is controlled by epigenetic mechanisms, we also evaluated the effect of the DNA methylase inhibitor 5-aza-2'-deoxycytidine (5-AZA-DC), and/or theand histone deacetylase inhibitors Trichostatin A (TSA) on their expression in bladder cancer cell lines.


METHODS
Expression of NY-ESO-1/LAGE-1, MAGE-A, MAGE-C1, BAGE, HOM-TES-85, SCP-1, SSX-1, SSX-2 and SSX-4 was analyzed by semi-quantitative RT-PCR and Western blotting on 10 normal urothelia, 23 24 superficial and 223 invasive tumours and on 10 cell lines treated with 5-aza-2'-deoxycytidine (5-AZA-DC) and/or Trichostatin A (TSA).


RESULTS
Expression of all CTA genes could be observed in at least 1 tumour except for HOM-TES-85 for which mRNA was never detected. MAGE-A, BAGE and NY-ESO-1/LAGE-1 mRNAs were the most frequently detected, respectively in 5677%, 212% and 89% of superficial and in 6461%, 4139% and 276% of invasive tumours. With the exception of MAGE-A, CTA transcripts were rarely detected in the cell lines. However, expression of all CTA genes, except SCP-1, could be induced at various levels by the drugs and 5-AZA-DC was a much more potent inducer than TSA.


CONCLUSIONS
These data suggest that immunotherapy of bladder cancer could target CTAs, especially those expressed at higher frequency such as MAGE-A, BAGE and NY-ESO-1/LAGE-1. Moreover, their induction by chemotherapeutic agents such as 5-AZA-DC, provides a potential pretreatment aimed at inducing the immunogenicity of the tumours.
Fradet
Yves
Y
Laboratoire d'Uro-Oncologie Expérimentale, Centre de recherche en cancérologie de l'Université Laval, CHUQ-L'Hôtel-Dieu de Québec, Canada.
Picard
V
V
Bergeron
A
A
LaRue
H
H
D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D045744:Cell Line, Tumor; D006801:Humans; D008297:Male; D013736:Testicular Neoplasms / Q000276:immunology*; D001749:Urinary Bladder Neoplasms / Q000378:metabolism*
D000951:Antigens, Neoplasm