B-365 Serum MAGE-A3 and MAGE-A4 Protein Levels as Potential Prognostic Biomarkers for Lung Cancer

Abstract Background Melanoma-associated antigen 3 (MAGE-A3) and MAGE-A4 are members of Melanoma Antigen Gene (MAGE) family, which have restricted expression to the testis and are abnormally expressed in cancer cells. MAGE-A3 and MAGE-A4 are overexpressed in lung cancer and have been shown to be associated with cancer progression and poor prognosis. Elevated MAGE-A4 protein level in lung cancer serum samples has been reported in the literature, however, it is unclear whether MAGE-A3 protein can be detected in serum samples of lung cancer patients. Methods We developed human MAGE-A3 and MAGE-A4 sandwich ELISA kits and used them to measure serum MAGE-A3 and MAGE-A4 protein levels in 21 lung cancer patients and 30 non-cancer controls. Results Serum MAGE-A3 protein was detected in all 21 lung cancer patients (range: 34 to 78871 pg/mL, mean: 5600 pg/mL) and was significantly elevated compared to non-cancer controls (range: 23–308 pg/mL, mean: 140 pg/mL) (P < 0.05). Serum MAGE-A4 protein was detected in 5 of 21 (24%) lung cancer patients (range: 280 to 35096 pg/mL, mean: 1819 pg/mL), and the samples with high serum MAGE-A4 concentration matched those with high serum MAGE-A3 concentration. Serum MAGE-A4 protein was not detectable in non-cancer controls. Conclusion Our findings suggest that serum MAGE-A3 and MAGE-A4 may serve as potential prognostic biomarkers for lung cancer. The detection of elevated serum MAGE-A3 and MAGE-A4 in lung cancer patients indicates their specificity for the disease. Larger studies with more samples, different cancer stages, and longer follow-up are needed to validate these results and establish the clinical utility of serum MAGE-A3 and MAGE-A4 levels as prognostic markers for lung cancer. If further validated, these biomarkers could aid in early diagnosis and better management of lung cancer.