The ATRX Knockout HeLa Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of HeLa cells engineered to disrupt the ATRX gene, generating a loss-of-function model for studying chromatin remodeling and telomere maintenance. This non-clonal pool retains genetic heterogeneity, providing a more physiologically relevant representation of cancer cell populations and enabling robust, unbiased functional analyses.
HeLa cells originate from an HPV18-positive cervical adenocarcinoma and display rapid proliferation and high tumorigenic potential. As one of the most extensively characterized human cell lines, they offer a well-defined background for examining the interplay between viral oncoproteins and host chromatin regulators such as ATRX.
ATRX forms a chromatin remodeling complex with DAXX that deposits histone H3.3 into heterochromatic regions, including telomeres, pericentric repeats, and silenced loci. This function is modulated by ATM/ATR kinase signaling and involves interactions with HP1??, HP1??, EZH2, and MeCP2 to maintain transcriptional silencing and chromatin compaction. ATRX loss disrupts H3.3 deposition, leading to chromatin relaxation, derepression of repetitive elements, and chronic activation of the alternative lengthening of telomeres (ALT) pathway, a hallmark of many aggressive cancers.
Within the HeLa model, ATRX knockout enables dissection of the molecular switch to ALT, a key telomere maintenance mechanism in tumors such as gliomas, sarcomas, and pancreatic neuroendocrine tumors. Additionally, ATRX mutations are implicated in ??-thalassemia myelodysplasia syndrome and X-linked intellectual disability (ATR-X syndrome). The HPV-positive background allows for concurrent study of viral oncoprotein effects on chromatin dynamics, and the polyclonal knockout population recapitulates the heterogeneity of ALT activation observed in patient samples.
Researchers can employ these cells in C-circle assays to quantify ALT activity, telomere fluorescence in situ hybridization (FISH) for telomere length and structure, and RT-qPCR for telomeric repeat-containing RNA (TERRA) levels. Chromatin immunoprecipitation (ChIP-qPCR) permits analysis of H3.3 occupancy at telomeric regions, while immunofluorescence detects PML body?Ctelomere colocalization. Western blotting confirms ATRX loss and H3.3 alterations. Proliferation and drug sensitivity assays facilitate screening for ALT-targeted therapeutics and epigenetic modulators. For further information, please contact Ascent Research.
