The ANXA4 Knockout HT29 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population engineered to disrupt the ANXA4 gene in the HT29 human colorectal adenocarcinoma cell line. This loss-of-function model is generated through CRISPR-mediated gene ablation and is provided as a non-clonal, heterogeneous pool of edited cells, allowing researchers to interrogate the biological roles of annexin A4 without the confounding effects of clonal selection. The polyclonal format preserves genetic diversity while ensuring robust target gene disruption across the population.
HT29 cells are a well-characterized epithelial cell line derived from a primary colorectal adenocarcinoma. They are widely utilized as a model for colon cancer biology, including studies of tumor progression, drug sensitivity, and signal transduction. The cells retain epithelial morphology and are commonly employed in xenograft models and in vitro assays of colorectal carcinogenesis. The use of HT29 as the parental line provides a relevant genetic and epigenetic background for dissecting the contribution of ANXA4 to colorectal cancer phenotypes.
ANXA4 encodes annexin A4, a calcium-dependent phospholipid-binding protein that modulates membrane repair, exocytosis, and inflammatory signaling. Annexin A4 negatively regulates cytosolic phospholipase A2 (PLA2G4A) by competing for phospholipid substrates, thereby controlling arachidonic acid release and prostaglandin synthesis. ANXA4 is regulated by transcription factors NF-??B (NFKB1) and TP53, as well as by HIF1A and calcium ions, and is subject to promoter methylation. Downstream, ANXA4 influences NF-??B signaling through interactions with NFKB1/p50 and modulates the actin cytoskeleton. It also affects the expression of CDH1 (E-cadherin) and matrix metalloproteinase MMP9, linking it to cell adhesion and invasion. Additionally, ANXA4 participates in Wnt/??-catenin (CTNNB1/TCF4) signaling, further linking it to proliferation and drug resistance.
In the context of HT29 colorectal adenocarcinoma cells, ANXA4 knockout is anticipated to abrogate annexin A4-mediated inhibition of PLA2G4A, leading to altered phospholipid metabolism and enhanced NF-??B activity. The HT29 cell line carries mutations in APC and TP53, making it an ideal platform to study how loss of ANXA4 intersects with these oncogenic drivers. The interplay between ANXA4 and the Wnt pathway is particularly relevant, as HT29 cells exhibit constitutive Wnt signaling. Disruption of ANXA4 may shift the balance of canonical Wnt/??-catenin and NF-??B crosstalk, impacting cell proliferation, migration, and susceptibility to chemotherapeutic agents. This model thus enables investigation of ANXA4 as a modulator of colon cancer progression and therapeutic response.
This knockout model facilitates dissection of ANXA4-dependent mechanisms via various assays. Western blotting and RT-qPCR confirm gene disruption; Sanger sequencing verifies genomic editing. The impact on NF-??B signaling can be quantified using NF-??B luciferase reporter constructs, and PLA2 activity assays measure altered phospholipase regulation. Cell viability, migration, and invasion assays assess phenotypes; drug sensitivity assays assess chemotherapeutic response. Immunofluorescence visualizes residual annexin A4 localization. For further details on this and other cell models, please contact Ascent Research.
