AMBRA1 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the AMBRA1 gene in the HT29 human colorectal adenocarcinoma cell line. This heterogeneous knockout pool provides a versatile loss-of-function model for interrogating autophagy and ubiquitin-proteasome pathways without the biases of clonal selection, facilitating robust analysis in a cancer-relevant context.
Derived from a primary colorectal adenocarcinoma, HT29 cells display epithelial morphology and harbor inactivating mutations in APC and TP53, leading to aberrant Wnt/??-catenin signaling and defective DNA damage responses. Historically, as a well-established intestinal epithelial model, HT29 cells are extensively used to study colorectal cancer progression, metabolic adaptation, and therapy resistance, offering a physiologically relevant background for gene disruption.
AMBRA1 functions as a positive regulator of autophagy by scaffolding the Beclin-1-VPS34 phosphoinositide 3-kinase complex, an interaction essential for autophagosome nucleation. Its activity is activated by mTORC1 inactivation and ULK1 phosphorylation, and it is transcriptionally regulated by FOXO factors. Downstream, AMBRA1 promotes LC3-II conversion and p62/SQSTM1 degradation, and interacts with Parkin to coordinate mitophagy. In parallel, AMBRA1 serves as a substrate recognition receptor for the CUL4-DDB1 E3 ubiquitin ligase, targeting c-Myc for polyubiquitination and proteasomal degradation, thereby suppressing cyclin D1 expression and restraining cell cycle progression. Through these dual mechanisms, AMBRA1 integrates signals from PI3K/AKT/mTOR, DNA damage sensors ATM/ATR, and metabolic stress pathways.
In the HT29 colorectal adenocarcinoma background, loss of AMBRA1 is expected to impair autophagic capacity and stabilize c-Myc, reflecting its dual tumor-suppressive roles. The inherent APC and TP53 defects create a hyperproliferative milieu that accentuates dependence on balanced cell cycle control and protein degradation. Consequently, this polyclonal knockout model enables dissection of AMBRA1 contributions to tumorigenesis, drug sensitivity, and autophagy-related resistance mechanisms.
Typical applications include monitoring autophagic flux via LC3-II and p62 western blotting and LC3 puncta immunofluorescence, assessing c-Myc protein stability through cycloheximide chase assays, measuring cell cycle alterations by flow cytometry, and evaluating chemotherapeutic sensitivity. Co-immunoprecipitation studies can probe AMBRA1 interactions with Beclin-1-VPS34 or CUL4-DDB1 complexes. For detailed product specifications and technical support, please contact Ascent Research.
