Myeloid-derived suppressor cells infiltration in non-small-cell lung cancer tumor and MAGE-A4 and NY-ESO-1 expression

Cancer/testis antigens melanoma-associated antigen 4 (MAGE-A4) and New York esophageal squamous cell carcinoma-1 (NY-ESO-1) are of clinical interest as biomarkers and present valuable targets for immunotherapy; however, they are poor prognostic markers in non-small cell lung cancer (NSCLC). In addition, myeloid derived suppressor cells (MDSCs) are recognized as a key element in tumor escape and progression. The aim of the present study was to investigate the diagnostic and prognostic value of MAGE-A4 and NY-ESO-1, and their association with MDSCs in NSCLC samples. The expression levels of MAGE-A4 and NY-ESO-1, and the infiltration of MDSCs (CD33(+)), were analyzed by immunohistochemistry of 67 tissue samples from patients with NSCLC. Overall, 58.33% of the NSCLC squamous cell carcinoma tissues and 94.7% of adenocarcinoma tissues were positive for MAGE-A4. NY-ESO-1 expression was observed in 52.78% of the squamous cell carcinoma tissues and 80% of the adenocarcinoma tissues. In primary adenocarcinoma tumor tissues, MAGE-A4 and NY-ESO-1 demonstrated a higher intensity of expression compared with the squamous cell carcinoma tissues. A total of 33 (91.7%) squamous cell carcinoma and 19 (95.0%) adenocarcinoma specimens were positive for CD33. The expression of MAGE-A4 and NY-ESO-1 antigens and infiltration of MDSCs was associated with poor prognosis of patients with NSCLC. Further studies investigating the association between these findings and underlying molecular mechanisms are required.