Quantitative expression and immunogenicity of MAGE-3 and -6 in upper aerodigestive tract cancer.
The MAGE antigens are frequently expressed cancer vaccine targets. However, quantitative analysis of MAGE expression in upper aerodigestive tract (UADT) tumor cells and its association with T-cell recognition has not been performed, hindering the selection of appropriate candidates for MAGE-specific immunotherapy. Using quantitative RT-PCR (QRT-PCR), we evaluated the expression of MAGE-3/6 in 65 UADT cancers, 48 normal samples from tumor matched sites and 7 HLA-A*0201+ squamous cell carcinoma of the head and neck (SCCHN) cell lines. Expression results were confirmed using Western blot. HLA-A*0201:MAGE-3- (271-279) specific cytotoxic T lymphocytes (MAGE-CTL) from SCCHN patients and healthy donors showed that MAGE-3/6 expression was highly associated with CTL recognition in vitro. On the basis of the MAGE-3/6 expression, we could identify 31 (47%) of the 65 UADT tumors, which appeared to express MAGE-3/6 at levels that correlated with efficient CTL recognition. To confirm that the level of MAGE-3 expression was responsible for CTL recognition, 2 MAGE-3/6 mRNA(high) SCCHN cell lines, PCI-13 and PCI-30, were subjected to MAGE-3/6-specific knockdown. RNAi-transfected cells showed that MAGE expression and MAGE-CTL recognition were significantly reduced. Furthermore, treatment of cells expressing low MAGE-3/6 mRNA with a demethylating agent, 5-aza-2'-deoxycytidine (DAC), increased the expression of MAGE-3/6 and CTL recognition. Thus, using QRT-PCR UADT cancers frequently express MAGE-3/6 at levels sufficient for CTL recognition, supporting the use of a QRT-PCR-based assay for the selection of candidates likely to respond to MAGE-3/6 immunotherapy. Demethylating agents could increase the number of patients amenable for targeting epigenetically modified tumor antigens in vaccine trials.
Filho
Pedro A Andrade
PA
Department of Otolaryngology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.
López-Albaitero
Andrés
A
Xi
Liqiang
L
Gooding
William
W
Godfrey
Tony
T
Ferris
Robert L
RL
D000951:Antigens, Neoplasm / Q000378:metabolism*; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D003602:Cytotoxicity, Immunologic; D019175:DNA Methylation; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007371:Interferon-gamma / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D009363:Neoplasm Proteins / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000473:pathology
D000951:Antigens, Neoplasm; C072013:MAGEA3 protein, human; C095203:MAGEA6 protein, human; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D007371:Interferon-gamma