The BLMH Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the human BLMH (bleomycin hydrolase) gene is disrupted in the HAP1 host background. This heterogeneous pool provides a complete loss-of-function model without clonal selection, enabling robust assessment of bleomycin hydrolase enzymatic activity in bulk cell assays. The product is ideal for researchers seeking to interrogate BLMH-dependent pathways in drug metabolism, antigen processing, and neurodegenerative disease mechanisms.
HAP1 is a human near-haploid chronic myelogenous leukemia (CML) cell line derived from the KBM-7 donor, a male patient in blast crisis. Its near-haploid genome??diploid only for chromosome 8??simplifies loss-of-function genetics by requiring disruption of a single allele, thereby eliminating confounding compensation from homologous copies. This genetic tractability makes HAP1 a preferred platform for CRISPR-based functional genomics and drug target validation.
The BLMH gene product is a cytoplasmic cysteine protease that is constitutively expressed and subject to stress-responsive transcriptional control. BLMH directly interacts with and degrades key substrates: it inactivates the chemotherapeutic drug bleomycin, preventing DNA double-strand breaks and subsequent activation of DNA repair proteins such as ATM and ??H2AX; it processes amyloid-beta peptides generated from amyloid precursor protein (APP), thereby regulating peptide clearance in Alzheimer??s disease models; and it trims intracellular peptides for MHC class I antigen presentation. Additionally, BLMH hydrolyzes homocysteine-thiolactone, linking it to homocysteine metabolism and glutathione recycling. The protease also participates in cellular protein turnover by degrading oxidized and misfolded polypeptides.
In the HAP1 near-haploid context, disruption of BLMH yields a cell model that is hypersensitive to bleomycin-induced DNA damage due to abolished drug inactivation, making it a powerful tool for studying chemotherapy resistance mechanisms in leukemia. Concurrently, loss of amyloid-beta degradation activity mimics aspects of cerebral amyloid accumulation, supporting Alzheimer??s disease research. The polyclonal format circumvents clonal variation and ensures a diverse allele spectrum, while the high knockout efficiency intrinsic to HAP1 cells guarantees depletion of BLMH protein, as verified by western blotting and functional sensitivity assays.
Researchers can apply this model in bleomycin dose-response cytotoxicity assays, ??H2AX focus formation immunofluorescence, RT-qPCR for transcript quantification, and caspase-3 activation analysis for apoptosis. Further applications include amyloid-beta degradation measurements, high-content screening for bleomycin sensitizers, and genome-wide CRISPR modifier screens to identify genetic interactors of BLMH. These polyclonal knockout cells also support functional studies of homocysteine metabolism and antigen processing. For additional product details, please contact Ascent Research.
