The ALPP Knockout HAP1 Polyclonal Cells product consists of a CRISPR/Cas9-edited polyclonal cell population derived from the HAP1 near-haploid cell line, with targeted disruption of the ALPP gene that encodes a GPI-anchored alkaline phosphatase. This loss-of-function model enables systematic investigation of ALPP-dependent processes such as extracellular nucleotide hydrolysis, purinergic signaling, cell adhesion, and migration, particularly in tumorigenesis contexts. The polyclonal format maintains genetic heterogeneity, making it ideal for functional genomics screens and assays where clonal variation is to be minimized.
HAP1 is a human male near-haploid cell line originally generated from the KBM-7 chronic myeloid leukemia (CML) line, possessing a haploid karyotype with the exception of disomy for chromosome 8. The near-haploid state permits efficient gene inactivation through single-allele targeting, establishing HAP1 as a robust platform for CRISPR-based functional genomics and haploid genetic screens. As a CML model, HAP1 cells retain the BCR-ABL1 fusion oncoprotein, providing a relevant hematopoietic background for studying signaling pathways linked to myeloid malignancies.
ALPP localizes to the outer plasma membrane as a GPI-anchored hydrolase that catalyzes the dephosphorylation of phosphate monoesters under alkaline conditions, releasing inorganic phosphate and alcohols. Its activity regulates the balance of extracellular ATP and AMP, driving adenosine generation, which subsequently engages adenosine receptors (A1, A2A, A2B, A3) and stimulates adenylate cyclase-mediated cAMP production. Transcriptionally, ALPP is governed by upstream regulators including cAMP, retinoic acid, butyrate, steroid hormones, and the transcription factors SP1 and TFAP2A. Functionally, ALPP dephosphorylates proteins within cell adhesion complexes and associates with lipid raft components such as caveolin-1 and flotillin, forming homodimers with other alkaline phosphatase isozymes in membrane microdomains.
Within the HAP1 near-haploid context, ALPP knockout creates a streamlined system to dissect the enzyme??s role in purinergic signaling and cell migration, processes frequently dysregulated in CML and other cancers. Although ALPP is best known as a tumor marker for germ cell tumors, its capacity to modulate extracellular adenine nucleotides and adenosine receptor pathways is relevant to hematopoietic malignancies, where autocrine adenosine signaling can contribute to immune suppression. The haploid nature of HAP1 ensures uniform loss of ALPP protein, facilitating unambiguous genotype-phenotype correlations.
This polyclonal ALPP knockout pool serves a broad spectrum of research applications, including tumor marker characterization, GPI-anchor biology, and purinergic signaling pathway dissection. Standard confirmation methods such as Western blot, flow cytometry, and immunofluorescence verify ALPP deletion, while enzymatic activity and adenosine quantification assays measure functional outcomes. The model is also suitable for drug metabolism investigations, migration studies, and drug sensitivity screening, particularly where ALPP-mediated dephosphorylation may affect therapeutic responses. Complementary transcriptomic approaches including RNA-seq and RT-qPCR can reveal gene expression programs altered by ALPP loss. For comprehensive technical details or customized services, please contact Ascent Research.
