The ID3 Knockout Ca Ski Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the gene encoding inhibitor of DNA binding 3 (ID3) in the human Ca Ski cervical carcinoma cell line. This polyclonal pool comprises a heterogeneous mix of cells carrying various CRISPR/Cas9-mediated disruptions to the ID3 locus, providing a powerful loss-of-function model for studying gene function without the clonal selection constraints of a single cell line. By eliminating ID3 expression, researchers can directly assess its regulatory roles in cellular proliferation, differentiation, and survival pathways, particularly within the context of cervical cancer biology.
The host Ca Ski cell line was established from an epithelial metastasis of a cervical squamous cell carcinoma to the small intestine, and it stably maintains integrated human papillomavirus type 16 (HPV-16) genomic DNA. This unique background makes Ca Ski cells an invaluable in vitro system for investigating HPV-driven oncogenesis, viral-host interactions, and the molecular mechanisms underlying cervical carcinoma progression. The epithelial origin and tumorigenic properties of Ca Ski cells further support studies in cancer cell biology, metastasis, and therapeutic intervention testing.
ID3 functions as a dominant-negative inhibitor of basic helix-loop-helix (bHLH) transcription factors by forming inactive heterodimers with ubiquitously expressed E proteins, including TCF3, TCF4, and TCF12. This sequestration prevents E proteins from dimerizing with tissue-specific bHLH activators such as MYOD1 and NEUROD1, thereby repressing transcription of genes that drive differentiation. In cancer, ID3 is often overexpressed and acts downstream of multiple oncogenic and microenvironmental signals: it is transcriptionally upregulated by TGFB1, BMP2, BMP4, NOTCH1, MYC, HIF1A, IL6, and EGF. Elevated ID3 levels repress the cyclin-dependent kinase inhibitors CDKN1A and CDKN2B, promote expression of the anti-apoptotic protein BCL2, and derepress the angiogenic factor VEGFA, collectively facilitating unchecked cell cycle progression, resistance to apoptosis, and enhanced angiogenesis. ID3 also interacts with the transcription factor TWIST1, linking it to epithelial-mesenchymal transition and invasive phenotypes.
In the Ca Ski cellular context, possessing integrated HPV-16 DNA, ID3 ablation removes a critical oncogenic barrier, thereby releasing E proteins to re-engage bHLH-driven differentiation and tumor-suppressive programs. This knockout model is particularly relevant for dissecting how HPV oncoproteins such as E6 and E7 cooperate with host factors like ID3 to sustain proliferation and evade apoptosis. It also enables exploration of the crosstalk between viral pathogenesis and endogenous TGF-beta/BMP/Notch signaling networks, offering a platform to identify vulnerabilities in cervical cancer and other ID3-overexpressing malignancies, including breast, prostate, and colorectal cancers.
This polyclonal knockout product is suited for a wide array of experimental applications: examining cell proliferation via MTT or BrdU assays, apoptosis through Annexin V staining or caspase-3 activity measurements, and angiogenesis by endothelial tube formation assays. It further permits detailed signaling analysis using Western blotting, RT-qPCR, co-immunoprecipitation of bHLH complexes, flow cytometric profiling, and reporter-based transcriptional activity assays. The mixed population nature allows for robust, statistically grounded studies of ID3 loss in cancer biology, HPV-mediated carcinogenesis, drug resistance, and stemness research. For further information or technical inquiries, please contact Ascent Research.
