The ASF1A Knockout SK-HEP-1 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population in the SK-HEP-1 human hepatocellular carcinoma cell line, designed for investigating loss-of-function phenotypes of the ASF1A gene. By disrupting ASF1A via CRISPR/Cas9-mediated gene disruption, this polyclonal model avoids clonal selection bias and provides a heterogeneous population that mirrors native cellular contexts. It serves as a versatile tool to dissect the role of ASF1A in chromatin dynamics, nucleosome assembly, and genome maintenance, supporting a broad range of functional and mechanistic studies in hepatocellular carcinoma research.
The host cell line SK-HEP-1 is a well-characterized human hepatocellular carcinoma model derived from a liver adenocarcinoma. With an epithelial morphology and robust tumorigenic properties, SK-HEP-1 cells are widely employed to explore liver cancer cell biology, including proliferation, signaling, and drug response. Their genetic background and widely documented behavior make them an appropriate platform for studying chromatin-related pathways and for evaluating the impact of gene knockouts on hepatocellular carcinoma cellular processes.
ASF1A functions as a critical histone H3-H4 chaperone, binding newly synthesized H3-H4 dimers and delivering them to the CAF-1 complex (CHAF1A/CHAF1B) at replication forks and to the HIRA complex at damaged chromatin. This delivery is essential for nucleosome assembly and disassembly during DNA replication, repair, and transcription. ASF1A activity is precisely regulated by upstream kinases, including TLK1 and TLK2, which phosphorylate ASF1A, and by the DNA damage-responsive kinases ATM and ATR. Transcriptionally, E2F1 controls ASF1A expression. In turn, ASF1A interacts with factors such as RAD54, MCM2-7, and PCNA, coordinating histone supply with replication fork progression and chromatin restoration. This signaling network integrates cell cycle progression with chromatin integrity, positioning ASF1A at the nexus of DNA replication, repair, and transcription.
In hepatocellular carcinoma, ASF1A is often upregulated to sustain high proliferative rates and manage replication stress. Knocking out ASF1A in SK-HEP-1 cells disrupts the histone chaperone cycle, leading to defective nucleosome assembly at replication forks and damaged sites. This results in replication stress, accumulation of DNA damage marked by ??H2AX, and transcriptional dysregulation, potentially compromising hepatocellular carcinoma cell growth and survival. The polyclonal knockout model enables exploration of chromatin vulnerability in liver cancer, including how ASF1A loss affects DNA damage tolerance, cell cycle progression, and response to chemotherapeutics, providing mechanistic insights into chromatin-targeted therapeutic strategies.
This knockout product is suited for a wide range of experimental applications, including chromatin biology investigations via Western blotting, RT-qPCR, RNA-seq, and ChIP-qPCR for histone modifications. Functional assays such as MTT, colony formation, and flow cytometry can assess cell proliferation and cell cycle alterations, while DNA fiber assays enable precise evaluation of replication fork dynamics under replication stress. Researchers can employ these cells for drug target validation, chromatin assembly assay development, and mechanistic studies of the CAF-1/HIRA pathways. For further information, please contact Ascent Research.
