Fonsatti Ester, Nicolay Hugues J M, Sigalotti Luca, Calabrò Luana, Pezzani Laura, Colizzi Francesca, Altomonte Maresa, Guidoboni Massimo, Marincola Francesco M, Maio Michele
Division of Medical Oncology and Immunotherapy, Department of Oncology, University Hospital of Siena, Istituto Toscano Tumori, Siena, Italy.
Clin Cancer Res. 2007 Jun 1;13(11):3333-8. doi: 10.1158/1078-0432.CCR-06-3091.
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.
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.
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.
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.
研究DNA低甲基化剂5-氮杂-2'-脱氧胞苷（5-aza-CdR）提高针对黑素细胞分化抗原的免疫治疗方法有效性的潜力。
通过实时逆转录PCR和间接免疫荧光（IIF）分析，研究5-aza-CdR对11种人黑素瘤细胞系中gp100组成性表达的影响。通过对所研究的黑素瘤细胞进行IIF分析，研究5-aza-CdR介导的人白细胞抗原（HLA）I类抗原水平表达变化以及HLA-A2同种特异性、细胞间黏附分子-1（ICAM-1）和白细胞功能相关抗原-3的变化。通过铬释放试验、干扰素-γ释放试验和干扰素-γ酶联免疫斑点试验，研究经或未经5-aza-CdR处理的gp100阳性Mel 275黑素瘤细胞被HLA-A2限制性gp100（209-217）特异性细胞毒性T淋巴细胞（CTL）识别的情况。
在所研究的所有黑素瘤细胞上，5-aza-CdR未影响gp100的组成性表达。与未处理细胞相比，Mel 275黑素瘤细胞暴露于5-aza-CdR后，其HLA I类抗原和ICAM-1的表达显著上调（P < 0.05）。这些表型变化显著增加了gp100特异性CTL对经5-aza-CdR处理的Mel 275黑素瘤细胞的裂解作用，并增加了它们的干扰素-γ释放。用5-aza-CdR处理Mel 275细胞还诱导更多gp100特异性CTL分泌干扰素-γ。
5-aza-CdR治疗通过上调HLA I类抗原表达提高了gp100特异性CTL对黑素瘤细胞的识别；ICAM-1也促成了这一现象。这些发现突出了5-aza-CdR与针对多种黑素瘤相关抗原的主动或过继性免疫治疗方法联合使用时更广泛的治疗意义。
