5-aza-2'-deoxycytidine-induced expression of functional cancer testis antigens in human renal cell carcinoma: immunotherapeutic implications.
OBJECTIVE
Limited therapeutic options are presently available for advanced renal cell carcinoma (RCC). This study was designed to define the clinical potential of the DNA hypomethylating agent 5-aza-2'-deoxycytidine (5-AZA-CdR) in human RCC, through its control of the expression of "therapeutic targets" of the cancer testis antigen (CTA) family, and of the tumor-associated antigen RAGE-1, in RCC cells.


METHODS
Reverse transcription (RT)-PCR assays of a panel of RCC cells treated with 5-AZA-CdR, investigated the induction of the expression of several CTAs and of RAGE-1. Immunoprecipitation and Western blotting assessed whether the expression of CTA-specific mRNA induced by 5-AZA-CdR resulted in a translated protein of appropriate molecular weight. The functional activity of de novo expressed CTA was evaluated using (51)Cr release cytotoxicity assays of 5-AZA-CdR-treated HLA-A2-positive RCC cells using HLA-A2-restricted NY-ESO-1-specific CTLs.


RESULTS
Exposure to 5-AZA-CdR invariably induced the expression of the CTA MAGE-1, -2, -3, and -4, GAGE 1-6, and NY-ESO-1 in all of the RCC cells investigated. De novo expression of NY-ESO-1 was persistent, being still detectable 60 days after the end of treatment, and generated a functional protein efficiently recognized by HLA-A2-restricted NY-ESO-1-specific CTLs. 5-AZA-CdR also induced RAGE-1 expression in RAGE-1-negative RCC and sarcoma cells but not in neoplastic cells of different histology.


CONCLUSIONS
This study provides the scientific rationale to establish new strategies of chemoimmunotherapy in RCC patients. The well-defined immunogenicity of the investigated CTAs and of RAGE-1 suggest that systemic administration of 5-AZA-CdR represents a promising strategy to enhance the constitutively poor immunogenic potential of RCC cells, and to propose that virtually all RCC patients receive active and/or adoptive CTA- or RAGE-1-based immunotherapy.
Coral
Sandra
S
Cancer Bioimmunotherapy Unit, Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, 33081 Aviano, Italy.
Sigalotti
Luca
L
Altomonte
Maresa
M
Engelsberg
Arne
A
Colizzi
Francesca
F
Cattarossi
Ilaria
I
Maraskovsky
Eugene
E
Jager
Elke
E
Seliger
Barbara
B
Maio
Michele
M
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000628:therapy; D000077209:Decitabine; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000096:biosynthesis; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000628:therapy; D058950:Melanoma-Specific Antigens; D008565:Membrane Proteins; D020928:Mitogen-Activated Protein Kinases; D009363:Neoplasm Proteins / Q000096:biosynthesis; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000964:Antimetabolites, Antineoplastic; C104948:CTAG1B protein, human; D005136:Eye Proteins; C072011:MAGEA1 protein, human; C072013:MAGEA3 protein, human; D058950:Melanoma-Specific Antigens; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D000077209:Decitabine; C498978:MOK protein, human; D020928:Mitogen-Activated Protein Kinases; D001374:Azacitidine