Sulfated N-glycan Upregulation in Sera Predicts Early-Stage Breast Cancer

Abstract Background Breast cancer (BC) is a significant global health concern among women, and early detection plays a pivotal role in enhancing patient survival rates. Alterations in the structure and abundance of sulfated glycans have been linked to various diseases including cancer. However, due to their low abundance, analyzing sulfated glycans poses challenges, making the investigation of sulfated glycan profiles a topic of significant interest in the search for novel biomarkers for early BC detection. Methods In this study, we utilized a glycoblotting-based sulphoglycomic workflow to examine the presence of sulfated N-glycans in the serum of Ethiopian patients with BC. This approach integrates high-throughput glycoblotting enrichment technology, WAX separation, and MALDI-TOF MS. The sulfated N-glycan profiles in the whole serum of 76 BC patients and 20 age-matched healthy controls were analyzed. Results The findings revealed that seven monosulfated glycans were significantly upregulated in the serum of BC patients compared to that in the control group. Each identified glycan showed significant abundance with an AUC ≥ 0.8 and demonstrated high diagnostic accuracy in predicting early-stage BC patients. Sulfated glycans abundantly displayed terminal Lewis-type glycan epitopes, unlike their negligible presence in nonsulfated N-glycans in serum, whose abundance has been strongly associated with BC progression, metastasis, and immune invasion. Importantly, sulfated glycans were analyzed without removing the sialic group, allowing for a comprehensive evaluation of the sialylation status of the identified sulfated glycans. Conclusion To the best of our knowledge, this study represents the first quantitative analysis of sulfated N-glycans in patients with BC, identifying novel glyco-biomarkers with discriminatory potential in the early stages of BC.