The ATG7 Knockout DLD-1 Polyclonal Cells are a heterogeneous population of DLD-1 human colorectal adenocarcinoma cells engineered via CRISPR/Cas9-mediated disruption of the ATG7 gene. This polyclonal pool provides a powerful loss-of-function model for studying autophagy-dependent mechanisms in colorectal cancer. The cells retain the epithelial and tumorigenic characteristics of the parental DLD-1 line while lacking functional ATG7, enabling researchers to dissect the role of this essential autophagy factor in cancer cell biology.
The DLD-1 cell line was originally established from a colorectal adenocarcinoma of a male patient and is widely employed as a model for colorectal tumorigenesis. These adherent epithelial cells are tumorigenic in immunocompromised mice, recapitulating key aspects of colorectal cancer progression including uncontrolled proliferation, migration, and invasion. The DLD-1 background is particularly suited for investigating the interplay between autophagy and colorectal cancer cell survival, metastasis, and therapeutic resistance.
ATG7 encodes an E1-like ubiquitin-activating enzyme that is indispensable for two ubiquitin-like conjugation systems governing autophagy. Functioning downstream of nutrient-sensing kinases such as mTORC1 and AMPK, and transcription factors like TFEB and FOXO3, ATG7 becomes activated during starvation or hypoxia. It catalyzes the ATP-dependent activation of ATG12 and LC3 family members (MAP1LC3A, MAP1LC3B, GABARAP), transferring ATG12 to the E2 enzyme ATG10 and LC3 to ATG3. These reactions drive the covalent attachment of ATG12 to ATG5, which then complexes with ATG16L1, and the conjugation of LC3 to phosphatidylethanolamine to form lipidated LC3-II. The resulting protein complexes are critical for autophagosome elongation, cargo recognition, and lysosomal fusion, ultimately regulating bulk degradation of cytoplasmic materials, mitophagy, and pexophagy.
In the context of DLD-1 colorectal adenocarcinoma cells, ATG7-mediated autophagy plays a dual role, supporting tumor cell survival under metabolic stress while also modulating proliferation, anoikis resistance, and chemosensitivity. Disruption of ATG7 in this model enables investigation of autophagy’s contribution to colorectal cancer pathogenesis, including its influence on tumor growth, metastatic dissemination, and response to standard-of-care chemotherapeutics. This knockout model is therefore a valuable tool for dissecting the autophagy-dependent signaling networks that underlie colorectal cancer progression and for evaluating autophagy inhibition as a therapeutic strategy.
The ATG7 Knockout DLD-1 Polyclonal Cells are ideal for a broad range of functional assays. Researchers can monitor autophagic flux by western blotting for LC3-I/II conversion in the presence or absence of lysosomal inhibitors like chloroquine, and assess autophagosome formation via immunofluorescence detection of LC3 puncta. Cell-based assays including MTT or CellTiter-Glo viability measurements, colony formation studies, and transwell migration/invasion assays allow quantitative analysis of proliferation and metastatic potential. Flow cytometry using Annexin V/PI staining can determine apoptosis susceptibility. These applications make the cells suitable for autophagy mechanism studies, drug resistance profiling, and high-content screening of autophagy modulators. For further technical inquiries, please contact Ascent Research.
