Functional Up-regulation of Human Leukocyte Antigen Class I Antigens Expression by 5-aza-2′-deoxycytidine in Cutaneous Melanoma: Immunotherapeutic Implications

Abstract

Purpose: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. Experimental Design: The effect of 5-aza-CdR on the constitutive expression of gp100 was investigated in 11human 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-g release and IFN-g 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-CdRt reated Mel 275 melanoma cells by gp100-specific CTL and increased their IFN-g release. 5-aza-CdR treatment of Mel 275 cells also induced a higher number of gp100-specific CTL to secrete IFN-g. 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.Human leukocyte antigen (HLA) class I antigens play a crucial role in antitumor cellular immune responses (1, 2), and levels of expression of both HLA class I antigens and tumor-associated antigen (TAA) contribute to determine the extent of TAA-specific CTL recognition of neoplastic cells (3, 4). Thus, the identification of new strategies potentially able to up-regulate the expression of HLA class I antigens and/or of therapeutic TAA on neoplastic cells may improve the clinical effectiveness of T cell -based immunotherapeutic approaches in cancer patients.Along this line, we have shown that the DNA hypomethylating agent 5-aza-2 ¶-deoxycytidine (5-aza-CdR, Dacogen) up-regulates the constitutive cell surface expression of HLA class I antigens and of HLA class I allospecificities and concomitantly induces or up-regulates that of different cancer testis antigens (CTA) in cultured human melanomas (5). Furthermore, 5-aza-CdR administration has also proven to induce a persistent up-regulation of HLA class I antigens, along with a long-lasting induction and up-regulation of CTA expression, in human melanomas grafted into ...

Antitumor activity of epigenetic immunomodulation combined with CTLA-4 blockade in syngeneic mouse models

“…This observation is particularly appealing in view of the demonstration that the upregulation of HLA class I antigens induced by 5-AZA-CdR was per se sufficient to improve gp 100-specific cytotoxic T cell recognition of melanoma cells. 5 In addition, loss of expression of HLA class I molecules by tumor cells has been recently suggested to represent a mechanism of tumor resistance that can develop during CTLA-4 therapy with ipilimumab. 21 Therefore, the upregulation of HLA class I molecules induced by DNA hypomethylating agents in vivo could contribute to: (i) improve immune-recognition of neoplastic cells; (ii) recover the efficacy of CTLA-4 blockade in patients progressing to treatment due to down-regulation of HLA class I molecules on tumor cells.…”

“…2,3 Exposure of neoplastic cells to these agents effectively improved T cell recognition of melanoma and renal carcinoma cells in vitro. [3][4][5] This functional effect was found to be mediated, at least in part, by the upregulation of the expression of tumor antigens (e.g., Cancer Testis Antigens), HLA class I and accessory/co-stimulatory molecules by neoplastic cells. 3,4,6,7 To further explore the immunomodulatory potential of DNA hypomethylating agents, we also demonstrated that changes in genome-wide expression profiles induced by 5-AZA-CdR in BALB/c mice grafted with the murine mammary adenocarcinoma TS/A cells were preferentially observed in neoplastic tissues as compared to normal counterparts, and that they affected mainly immunologic pathways.…”

Cancer Testis Antigens in Cancer Immunotherapy

“…Важно, что приобретенные фенотипические изменения он-котрансформированных клеток поддерживаются популяциями опухолевых клеток и функционально значимы, индуцируя или существенно усиливая их распознавание СТА-специфичными ЦТЛ [46,47]. Fonsatti et al [48] продемонстрировали, что после ДГА-терапии одного только изменения уровня антигенов HLA класса I и CD54 на по-верхности клеток меланомы достаточно, чтобы существенно повысить их распознавание антиген-специфичными ЦТЛ.…”

Chemocentric Chemoimmunotherapy: A New Concept in Melanoma Immunotherapy

“…Additionally, some chemo drugs can modulate the expression of tumor antigens and antigen processing/presentation machinery on tumor cells. For example, 5-Fluorouracil (5-FU) has been shown to induce carcinoembryonic antigen (CEA) expression in colon and breast cancer cells (Correale et al, 2003) while 5-aza-2'-deoxycytidine can induce the expression of cancer testis antigens and the cell surface MHC class I complex in melanoma and other cancers (Adair & Hogan, 2009;Coral et al, 2002;Fonsatti et al, 2007;Natsume et al, 2008). Notably, direct intralesional injection of the MHC class I complex, which allows tumor immune evasion when defective in numerous cancers (Lampen & van Hall, 2011;Maleno et al, 2011), via high-dose Allovectin-7 ® (Vical Inc., San Diego, CA, USA), a cationic lipid-formulated bicistronic plasmid encoding MHC-I components -2 microglobulin and HLA-B7, in 127 recurrent or previously unresponsive to chemotherapy stage III and IV melanoma patients tested for efficacy in a recent phase II dose escalation study produced an objective response of 11.8% with median duration of response of 13.8 months (Bedikian et al, 2010).…”