Functional up-regulation of human leukocyte antigen class I antigens expression by 5-aza-2'-deoxycytidine in cutaneous melanoma: immunotherapeutic implications.
OBJECTIVE
To investigate the potential of the DNA hypomethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR) to improve the effectiveness of immunotherapeutic approaches against melanocyte differentiation antigens.


METHODS
The effect of 5-aza-CdR on the constitutive expression of gp100 was investigated in 11 human melanoma cell lines by real-time reverse transcription-PCR and indirect immunofluorescence (IIF) analyses. 5-aza-CdR-mediated changes in the levels of expression of human leukocyte antigen (HLA) class I antigens and HLA-A2 allospecificity, intercellular adhesion molecule-1 (ICAM-1), and leukocyte-function-associated antigen-3 were investigated by IIF analysis on melanoma cells under study. The recognition of gp100-positive Mel 275 melanoma cells, treated or not with 5-aza-CdR, by HLA-A2-restricted gp100((209-217))-specific CTL was investigated by (51)Cr-release assays, IFN-gamma release and IFN-gamma ELISPOT assays.


RESULTS
The constitutive expression of gp100 was not affected by 5-aza-CdR on all melanoma cells investigated. Compared with untreated cells, the exposure of Mel 275 melanoma cells to 5-aza-CdR significantly (P < 0.05) up-regulated their expression of HLA class I antigens and of ICAM-1. These phenotypic changes significantly (P < 0.05) increased the lysis of 5-aza-CdR-treated Mel 275 melanoma cells by gp100-specific CTL and increased their IFN-gamma release. 5-aza-CdR treatment of Mel 275 cells also induced a higher number of gp100-specific CTL to secrete IFN-gamma.


CONCLUSIONS
Treatment with 5-aza-CdR improves the recognition of melanoma cells by gp100-specific CTL through the up-regulation of HLA class I antigens expression; ICAM-1 also contributes to this phenomenon. These findings highlight a broader range of therapeutic implications of 5-aza-CdR when used in association with active or adoptive immunotherapeutic approaches against a variety of melanoma-associated antigens.
Fonsatti
Ester
E
Division of Medical Oncology and Immunotherapy, Department of Oncology, University Hospital of Siena, Istituto Toscano Tumori, Siena, Italy.
Nicolay
Hugues J M
HJ
Sigalotti
Luca
L
Calabrò
Luana
L
Pezzani
Laura
L
Colizzi
Francesca
F
Altomonte
Maresa
M
Guidoboni
Massimo
M
Marincola
Francesco M
FM
Maio
Michele
M
D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D000077209:Decitabine; D019084:Fluorescent Antibody Technique, Indirect; D015972:Gene Expression Regulation, Neoplastic; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007371:Interferon-gamma / Q000378:metabolism; D008545:Melanoma / Q000188:drug therapy* / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D015854:Up-Regulation; D058951:gp100 Melanoma Antigen
D015395:Histocompatibility Antigens Class I; D008562:Membrane Glycoproteins; C548637:PMEL protein, human; D058951:gp100 Melanoma Antigen; D000077209:Decitabine; D007371:Interferon-gamma; D001374:Azacitidine