The ATG4B Knockout SK-HEP-1 Polyclonal Cells are a CRISPR/Cas9-edited population derived from the human SK-HEP-1 hepatic adenocarcinoma cell line, engineered to disrupt the ATG4B gene. This loss-of-function model enables investigation of autophagy regulation in liver cancer. The polyclonal pool reflects heterogeneous editing, capturing broad functional consequences without clonal selection bias, allowing researchers to study ATG4B-dependent autophagic processes in tumor homeostasis and stress responses.
The parental SK-HEP-1 cell line originated from ascites of a liver adenocarcinoma patient. These cells display an endothelial-like phenotype and serve as a model for hepatic endothelial biology and hepatocellular carcinoma research. The line exhibits rapid proliferation, migratory ability, and apoptotic resistance, characteristics of malignant liver cells. Its tumorigenic context suits studies on autophagy and cancer cell survival, especially under nutrient deprivation or chemotherapy relevant to the hepatic tumor microenvironment.
ATG4B encodes a cysteine protease that processes LC3 family members (MAP1LC3A, MAP1LC3B, GABARAP, GABARAPL1) for autophagosome formation. It is regulated by mTORC1 and AMPK signaling and transcriptionally modulated by TFEB, acting in concert with the ULK1 complex. ATG4B cleaves pro-LC3 to expose a C-terminal glycine for conjugation to phosphatidylethanolamine by ATG7 and ATG3, essential for membrane elongation. The enzyme also delipidates LC3 from the outer autophagosomal membrane, enabling maturation and lysosomal fusion. Consequently, ATG4B governs autophagic flux and p62/SQSTM1 turnover, positioning it as a critical node in the autophagy pathway.
In SK-HEP-1 liver adenocarcinoma cells, ATG4B disruption blocks autophagosome formation, causing accumulation of LC3-I and p62 while reducing LC3-II. This defect impairs protein and organelle turnover, altering metabolic adaptability, proliferation, and invasive capacity. Under nutrient stress, these cells exhibit heightened sensitivity, highlighting the importance of autophagic recycling for survival. The model thus provides a platform to investigate autophagy’s role in hepatic cancer progression and to evaluate therapeutic strategies targeting autophagy dependencies.
Key applications of this polyclonal knockout model encompass autophagic flux assessment with bafilomycin A1, western blotting for LC3-II and p62, and fluorescence imaging of LC3 puncta. The cells support drug screening for autophagy modulators, viability profiling under metabolic stress, and migration or invasion assays to explore metastasis. Additionally, they facilitate protein stability studies and co-culture experiments to examine tumor microenvironment interactions. For further inquiries, contact Ascent Research.
