The ASF1B Knockout HeLa Polyclonal Cells product consists of a CRISPR/Cas9-edited polyclonal knockout cell population in which the ASF1B gene has been disrupted, providing a loss-of-function model for investigating ASF1B-dependent processes. This polyclonal pool contains a heterogeneous mixture of edited alleles, generated by transient transfection and selection without single-cell cloning, enabling researchers to study the collective impact of ASF1B deficiency in a human cell background. The knockout model is suitable for functional genomics, pathway analysis, and therapeutic target validation in cancer biology.
The host cell line, HeLa, is a widely used human cervical epithelial cell line derived from an HPV18-positive cervical adenocarcinoma. HeLa cells exhibit robust proliferation, well-characterized signaling networks, and permissiveness to genetic manipulation, making them an ideal chassis for dissecting cell cycle and DNA replication mechanisms. Their transformed phenotype and HPV-driven oncogenic background provide a clinically relevant context for studying chromatin dynamics and replication stress in cervical cancer.
ASF1B encodes a histone chaperone that forms complexes with histone H3-H4 dimers, delivering them to the CAF-1 complex (CHAF1A and CHAF1B) at DNA replication forks to facilitate nucleosome assembly on newly synthesized DNA. ASF1B also interacts with the HIRA complex, MCM2-7 helicase, RFC complex, and its paralog ASF1A, linking replication fork progression to chromatin restoration. Upstream, ASF1B expression is transcriptionally regulated by E2F1 and E2F4, downstream of the CDK2-CCNA2-RB1 axis, and is responsive to MYC-driven proliferation signals. Its activity promotes histone H3.1 deposition, PCNA loading, and efficient S-phase progression, thereby ensuring genome stability and cell cycle continuation.
In the HeLa cervical cancer model, ASF1B knockout disrupts the coordinated delivery of histones to replication forks, likely leading to replication stress, defective chromatin assembly, and impaired cell proliferation. Given the elevated replication demands of cancer cells and the poor prognosis associated with ASF1B overexpression in cervical, breast, colorectal, and hepatocellular carcinomas, this polyclonal knockout population offers a powerful tool to study synthetic lethal interactions, identify therapeutic vulnerabilities, and dissect the interplay between HPV oncoproteins and chromatin maintenance pathways.
Typical research applications include western blotting and RT-qPCR to confirm ASF1B depletion and assess downstream histone marks, cell proliferation and colony formation assays to quantify growth defects, flow cytometry for cell cycle analysis, DNA fiber assays to monitor replication fork dynamics, and chromatin immunoprecipitation to examine histone H3 occupancy. The model also supports drug sensitivity screens to identify compounds that selectively target ASF1B-deficient cancer cells. For additional details or custom requests, contact Ascent Research.
