The ID3 Knockout KYSE-30 Polyclonal Cells are a CRISPR/Cas9-mediated gene disruption product targeting the inhibitor of DNA binding 3 (ID3) locus in the KYSE-30 human esophageal squamous cell carcinoma line. This polyclonal knockout cell population comprises a heterogeneous pool of edited cells, collectively lacking functional ID3 protein, providing a physiologically relevant loss-of-function model that avoids the clonal selection bias of monoclonal lines. The polyclonal format is particularly advantageous for studies requiring cellular diversity, such as drug response profiling and pooled genetic screens.
The parental KYSE-30 cell line was derived from a poorly differentiated invasive esophageal squamous cell carcinoma of a 64-year-old Japanese male. It retains aggressive tumorigenic features, including high proliferative capacity and the ability to form xenograft tumors in immunodeficient mice, and endogenously expresses ID3, making it an ideal background for interrogating ID3 function in ESCC pathogenesis.
ID3 functions as a dominant-negative regulator of basic helix-loop-helix (bHLH) transcription factors by forming non-functional heterodimers with factors such as TCF3/E2A, TCF4, and TCF12, thereby blocking their DNA-binding and transcriptional activity. ID3 expression is activated by TGF-?? and BMP ligands through receptor-mediated phosphorylation of SMAD1/5/8, which partner with SMAD4 to directly induce ID3 transcription; additional inputs from retinoic acid and E2F1 further modulate its levels. Downstream, ID3 represses the cyclin-dependent kinase inhibitor p21/CDKN1A and upregulates cyclin D1, c-MYC, and the stemness regulators NANOG and SOX2, thereby inhibiting differentiation, promoting cell cycle progression, and maintaining a stem-like state.
In esophageal squamous cell carcinoma, ID3 is commonly overexpressed and contributes to a dedifferentiated, highly aggressive phenotype by sustaining proliferative signaling and resisting apoptosis. Disruption of ID3 in KYSE-30 cells is anticipated to relieve repression of TCF3-dependent targets, restore p21 expression, and suppress the NANOG/SOX2-mediated stem cell network, thus providing a powerful model to elucidate ID3??s role in tumor maintenance and to identify context-specific therapeutic vulnerabilities.
Applications of these polyclonal knockout cells include quantitative cell proliferation (CCK-8) and clonogenic survival assays, flow cytometric analysis of cell cycle distribution and apoptosis, transwell migration and invasion studies, and in vivo xenograft tumor growth evaluation. The heterogeneous population is well-suited for drug sensitivity screening and pooled functional genomics experiments, as it minimizes clone-specific artifacts. Transcriptomic profiling via RNA-seq can further define ID3-regulated gene networks. For technical support and custom requests, please contact Ascent Research.
