MGAT1, also known as UDP-GlcNAc:alpha3-D-mannoside beta1,2-N-acetylglucosaminyltransferase I (GnTI) or N-acetylglucosaminyltransferase I (GlcNAcT-1), is a key enzyme in N-glycosylation. It initiates the synthesis of complex N-glycans, which are involved in multiple biological processes, such as cell signaling, immune response, and protein stability. The Wnt/β-catenin signaling pathway can up-regulate MGAT1 at transcriptional and post-transcriptional levels [4].

Conditional deletion of the mouse Mgat1 gene (Mgat1 cKO) in spermatogonia causes a germ-cell autonomous defect leading to infertility. Loss of complex N-glycans due to Mgat1 deletion promotes premature up-regulation of genes in spermatogenesis and spermiogenesis, and affects ERK1/2 signaling, potentially via different mechanisms [3].

In pancreatic ductal adenocarcinoma (PDAC), high expression of MGAT1 is associated with better patient prognosis, and its overexpression inhibits PDAC cell proliferation and migration [1]. In Wilms' tumor, LINC00173 promotes tumor progression through MGAT1-mediated MUC3A N-glycosylation [2]. In hepatocellular carcinoma (HCC), MGAT1 is identified as a promising therapeutic target through single-cell and spatial transcriptomics analysis [5]. In triple-negative breast cancer, overexpression of MGAT1 leads to immune evasion by regulating CD73 membrane translocation [6]. In pancreatic cancer, microRNA-204-3p inhibits metastasis by down-regulating MGAT1 [7].

In conclusion, MGAT1 plays essential roles in multiple biological processes and diseases. Mgat1 cKO mouse models have revealed its significance in spermatogenesis and infertility. In various cancers like PDAC, Wilms' tumor, HCC, and triple-negative breast cancer, as well as in pancreatic cancer metastasis, MGAT1 is involved in regulating disease-related cellular behaviors. These findings provide important insights into the biological functions of MGAT1 and potential therapeutic targets for related diseases.