The ASGR1 knockout CAL-27 polyclonal cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed for investigating asialoglycoprotein receptor 1 (ASGR1) function in a human oral squamous cell carcinoma background. This product consists of a heterogeneous pool of CAL-27 cells carrying targeted disruptions in the ASGR1 gene, generated without single-cell cloning, thereby preserving natural variation while abrogating ASGR1 expression. The knockout approach eliminates receptor-mediated endocytosis of desialylated glycoproteins, providing a robust loss-of-function model for studying glycoprotein clearance mechanisms. Researchers can use these cells to explore ASGR1-dependent pathways, lysosomal degradation processes, and the receptor’s role in cancer biology, with applications spanning liver-targeted therapeutic development and metabolic disease research.
The parental CAL-27 cell line was established from a tongue squamous cell carcinoma of a 56-year-old male patient. CAL-27 cells are a widely used model for oral squamous cell carcinoma, exhibiting epithelial morphology and retaining key oncogenic features relevant to head and neck cancer research. Their rapid proliferation and stable culture characteristics make them suitable for CRISPR/Cas9 gene editing and subsequent functional assays. In the context of ASGR1 knockout, this host cell line enables examination of asialoglycoprotein receptor biology in a non-hepatic epithelial malignancy, offering insights into ectopic receptor expression and potential roles in cancer progression.
ASGR1 encodes the major subunit of the asialoglycoprotein receptor, a transmembrane lectin that mediates clathrin-dependent endocytosis of desialylated glycoproteins. The receptor forms a hetero-oligomeric complex with ASGR2 and interacts with the AP2 adaptor complex and dynamin to facilitate internalization. Following uptake, ligand?Creceptor complexes traffic through Rab5- and EEA1-positive early endosomes to lysosomes, where cathepsin proteases and other hydrolases degrade the glycoprotein cargo. ASGR1 expression is transcriptionally regulated by upstream factors including HNF4A, glucocorticoid receptor, and proinflammatory cytokines. The receptor’s activity directly impacts serum glycoprotein homeostasis by clearing aged or desialylated proteins, linking it to pathways governing lysosomal degradation, endocytic trafficking, and hepatic metabolic regulation.
In CAL-27 cells, ASGR1 knockout disrupts this endocytic axis, providing a unique platform to evaluate receptor function outside the liver. While ASGR1 is predominantly hepatic, its expression in oral squamous cell carcinoma raises questions about alternative roles in cancer cell biology, such as modulating extracellular glycoprotein composition or influencing tumor microenvironment interactions. The knockout model enables dissection of these functions and may reveal cancer-specific dependencies. Moreover, because ASGR1 variants are associated with non-alcoholic fatty liver disease, liver cirrhosis, and hepatocellular carcinoma, studying its loss in an epithelial cancer context could uncover shared pathogenic mechanisms or inform liver-targeted therapeutic strategies that require careful assessment of extrahepatic effects.
Typical research applications include quantifying ASGR1-mediated endocytosis via asialoorosomucoid uptake assays, assessing glycoprotein clearance dynamics, and profiling lysosomal degradation using immunofluorescence or Western blotting for cathepsin proteases and lysosomal hydrolases. Co-immunoprecipitation experiments can map interactions with clathrin, AP2, or ASGR2, while cell surface biotinylation and flow cytometry enable measurement of receptor internalization and recycling. Gene expression analysis by RT-qPCR and functional rescue experiments further validate knockout phenotypes. This knockout product is ideal for investigators exploring glycoprotein homeostasis, endocytic trafficking, and cancer cell signaling. For additional details or technical support, contact Ascent Research.
