The dysregulation of sialic acid is closely associated with oncogenesis and tumor progression. Most tumor cells exhibit sialic acid upregulation. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are receptors that recognize sialic acid and are expressed in various immune cells. The activity of Siglecs in the tumor microenvironment promotes immune escape, mirroring the mechanisms of the well-characterized PD-1/PD-L1 pathway in cancer. Cancer cells utilize sialic acid-linked glycans to evade immune surveillance. As Siglecs exhibit similar mechanisms as the established immune checkpoint inhibitors (ICIs), they are potential therapeutic targets for different forms of cancer, especially ICI-resistant malignancies. Additionally, the upregulation of sialic acid serves as a potential tumor biomarker. This review examines the feasibility of using sialic acid and Siglecs for early malignant tumor detection and discusses the potential of targeting Siglec–sialic acid interaction as a novel cancer therapeutic strategy.
唾液酸代谢失调与肿瘤发生及进展密切相关。多数肿瘤细胞呈现唾液酸表达上调现象。唾液酸结合免疫球蛋白样凝集素（Siglecs）作为识别唾液酸的受体，广泛表达于各类免疫细胞中。在肿瘤微环境中，Siglecs的活性会促进免疫逃逸，其作用机制与已明确的PD-1/PD-L1通路具有相似性。癌细胞通过唾液酸修饰的聚糖结构逃避免疫监视。鉴于Siglecs与现有免疫检查点抑制剂作用机制类似，它们有望成为多种癌症（特别是免疫检查点抑制剂耐药性恶性肿瘤）的潜在治疗靶点。此外，唾液酸表达上调可作为潜在的肿瘤生物标志物。本综述探讨了利用唾液酸及Siglecs进行早期恶性肿瘤检测的可行性，并分析了靶向Siglec-唾液酸相互作用作为新型癌症治疗策略的潜在价值。
肿瘤(癌症)患者之家