The CD44 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population designed to disrupt the human CD44 gene. This loss-of-function model enables functional analysis of CD44 in a near-haploid genetic background. The polyclonal format provides a diverse knockout pool for reproducible comparative studies. CRISPR/Cas9-mediated gene disruption ensures a clean genetic ablation without the off-target effects common to RNAi approaches, making it a reliable tool for investigating CD44-dependent processes.
The HAP1 cell line is a near-haploid chronic myeloid leukemia line derived from KBM-7. It displays adherent, fibroblast-like morphology and carries the BCR-ABL1 oncogene. With approximately 26 chromosomes, HAP1 lacks a functional heterozygous genome, simplifying knockout interpretation. Its leukemic origin and sensitivity to immunomodulatory drugs (IMiDs) make it particularly suited for cancer signaling and drug response studies. The haploid nature ensures that CD44 disruption is not compensated by a second allele, providing unambiguous knockout phenotypes.
CD44 is a transmembrane receptor for hyaluronic acid, osteopontin, and other ECM components. Ligand binding activates PI3K/Akt and MAPK/ERK1/2 pathways, while the cytoplasmic domain binds ERM proteins (ezrin, radixin, moesin) to link to the actin cytoskeleton. CD44 is regulated by NF-??B, AP-1, p53, and STAT3, and downstream modulates Rho GTPases, MMPs, and EMT transcription factors Snail and Twist. Proteolytic cleavage releases an intracellular domain that acts as a co-transcriptional regulator, promoting ??-catenin/TCF target gene expression.
In the HAP1 myeloid leukemia model, CD44 knockout enables dissection of its role in leukemic cell adhesion, homing, and drug resistance, free from confounding heterozygosity. CD44??s interaction with hyaluronic acid is critical for leukemia stem cell homing to the bone marrow, and its disruption can impair migration and survival. Combined with BCR-ABL1 signaling and IMiD sensitivity, this model allows investigation of crosstalk between adhesion receptors and oncogenic kinases in CML pathology.
This polyclonal knockout population is well-suited for flow cytometric CD44 detection, hyaluronic acid adhesion assays, and Transwell migration/invasion studies. Biochemical readouts include western blotting for Akt, ERK1/2, and NF-??B phosphorylation, and co-immunoprecipitation of CD44 with ezrin, radixin, or moesin. Transcriptomic analysis by RT-qPCR or RNA-seq can reveal CD44-dependent gene expression changes. The model is also amenable to high-throughput inhibitor screens and in vivo xenograft tumorigenesis assays to evaluate metastatic behavior. For additional information or to request a quote, please contact Ascent Research.
