Melanoma-associated antigen A11 reduces erlotinib and afatinib efficacy in head and neck cancer.

Melanoma-associated antigen A (MAGE-A) proteins are members of the cancer/testis antigens (CTA), and the expression of these proteins is almost exclusively limited to malignant cells, making them an attractive treatment target. MAGE-A expression is correlated with poor overall survival in several cancers, including head and neck squamous cell carcinoma (HNSCC). Among others, MAGE-A11 was found to be associated with resistance to different antineoplastic and targeted compounds, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). We searched The Cancer Genome Atlas (TCGA) database with a focus on MAGE-A and found that MAGE-A overexpression is a common event in HNSCC (27.5%). Furthermore, MAGE-A overexpression was correlated with significantly reduced overall survival (35.45 months vs. 64.78 months, P = 0.0173). In particular, MAGE-A11 overexpression was found in 9% of specimens. We then examined MAGE-A11 expression, the efficacy of EGFR and the EGFR mutational status and the effects of the pan-HER (human EGFR) TKIs erlotinib and afatinib in HNSCC cell lines. Next, we used a model of stable MAGE-A11 overexpression to demonstrate that MAGE-A11 impaired the efficacy of erlotinib and afatinib. In summary, our study provides evidence that MAGE-A11 contributes to erlotinib and afatinib resistance in head and neck cancer cell lines.

MAGE-A11 expression contributes to cisplatin resistance in head and neck cancer.

OBJECTIVE: The objective of this study is to investigate the roles of melanoma-associated antigens (MAGEs) in the cisplatin treatment of head and neck cancer. MATERIALS AND METHODS: We assessed the efficacy of cisplatin in a set of four head and neck cancer cell lines using a crystal violet assay. The MAGE-A expression in all cell lines was measured with RT-qPCR. The correlation between MAGE-A expression and cisplatin efficacy was investigated using Spearman's correlation analysis. Furthermore, we established a cell line with stable overexpression of MAGE-A11 and determined influence on proliferation, cisplatin efficacy and cell apoptosis. In this cell line, the effects of cisplatin were assessed using either crystal violet assays or flow cytometry (Annexin V). RESULTS: For MAGE-A11, we observed the highest correlation (r = 1.000, p = 0.0417) with low cisplatin efficacy. Stable overexpression of MAGE-A11 resulted in no changes in proliferation, but in lower cisplatin cytotoxicity and lower rates of apoptosis. Also, mouse double minute 2 homolog (MDM2) expression was induced by MAGE-A11 overexpression. CONCLUSION: We provide evidence that MAGE-A11 expression contributes to cisplatin resistance in head and neck cancer. CLINICAL RELEVANCE: Our study underscores the negative predictive role of MAGE-A11 expression in head and neck cancer.