The ANXA5 Knockout HT29 Polyclonal Cells represent a pool of CRISPR/Cas9-edited HT29 cells with targeted disruption of the ANXA5 gene, providing a polyclonal loss-of-function model for investigating annexin A5-dependent processes.
The HT29 cell line was originally established from a primary colorectal adenocarcinoma and serves as a widely used intestinal epithelial model. These cells exhibit an aneuploid karyotype, retain wild-type p53, and are competent to undergo differentiation under appropriate culture conditions, making them a relevant system for colorectal cancer research.
Annexin A5, encoded by ANXA5, is a member of the annexin family of calcium-dependent phospholipid-binding proteins. It exhibits high affinity for phosphatidylserine, a phospholipid normally restricted to the inner leaflet of the plasma membrane but externalized during apoptosis and cellular activation. Upstream regulators including epidermal growth factor (EGF), tumor necrosis factor-alpha (TNF-??), interleukin-1 beta (IL-1??), glucocorticoids, and vitamin D modulate ANXA5 expression. Upon binding to phosphatidylserine, annexin A5 inhibits coagulation by blocking procoagulant phospholipid surfaces, limiting thrombin generation and Factor Xa activation. Additionally, annexin A5 influences protein kinase C (PKC) signaling and cell surface integrin dynamics. It interacts with integrin ??1, the epidermal growth factor receptor (EGFR), collagen, and actin, linking membrane organization with cytoskeletal and adhesion pathways. In the context of apoptotic cell clearance, annexin A5 binds externalized phosphatidylserine exposed by phospholipid scramblase (TMEM16F) downstream of caspase 3 activation, bridging apoptotic cells to macrophage phosphatidylserine receptors such as TIM4 and BAI1 to facilitate non-inflammatory phagocytosis.
In the HT29 colorectal cancer background, ANXA5 disruption provides a valuable tool to dissect the role of phosphatidylserine-mediated signaling in tumor biology. Given the involvement of annexin A5 in apoptosis, proliferation, and drug sensitivity, this knockout model may reveal alterations in cell death pathways, growth kinetics, and response to chemotherapeutic agents. The HT29 line??s wild-type p53 status further allows exploration of p53-dependent and -independent mechanisms influenced by annexin A5 loss.
This polyclonal knockout cell population is suitable for a broad range of research applications. Apoptosis assays using Annexin V-FITC staining are informative for studying phosphatidylserine exposure independent of ANXA5. Proliferation can be measured via MTT/XTT assays, and migration potential evaluated by wound healing assays. Coagulation assays can probe the anticoagulant role of annexin A5, while drug sensitivity (IC50) studies help define chemoresistance mechanisms. Transcriptomic analysis by RNA-seq and protein expression by Western blotting or RT-qPCR enable molecular phenotyping. For technical support and additional information, please contact Ascent Research.
