The IFT88 Knockout 786-O Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human 786-O renal cell carcinoma line, in which the IFT88 gene has been disrupted to abolish expression of the intraflagellar transport complex B component IFT88. This heterogeneous loss-of-function model enables robust investigation of primary cilia-dependent processes and signaling cascades in a kidney cancer context. The polyclonal nature of the knockout population preserves a spectrum of genetic editing events, offering a system that better reflects the complexity of ciliary dysfunction than single-clone isolates while providing a reliable platform for functional genomic screens and pathway interrogation.
The host cell line, 786-O, originates from a clear cell renal cell carcinoma (ccRCC) with a well-characterized biallelic VHL mutation, leading to constitutive activation of hypoxia-inducible factor (HIF) pathways. These epithelial tumor cells are widely employed as a model for studying ccRCC biology and therapeutic vulnerabilities. In standard culture, 786-O cells often lack primary cilia, a phenotype that is further exacerbated by targeted IFT88 disruption, providing a clean background for evaluating ciliary restoration experiments or for probing cilia-independent signaling rewiring in cancer.
IFT88 is an essential core subunit of the intraflagellar transport B (IFT-B) complex, which assembles into anterograde IFT trains together with kinesin-2 motor proteins and other IFT-B members such as IFT52, IFT57, and IFT20. This macromolecular machinery transports ciliary cargo from the basal body to the tip, a process indispensable for ciliogenesis and cilium structural maintenance. IFT88 knockout abrogates primary cilium formation, thereby dampening ciliary-dependent signaling. The Hedgehog pathway is particularly affected: in the absence of a functional cilium, the transmembrane protein SMO cannot efficiently transduce signal to GLI transcription factors, leading to altered expression of Hedgehog target genes including PTCH1 and GLI1. Additionally, IFT88 loss perturbs ciliary-mediated modulation of PDGF signaling components and ciliary membrane protein trafficking, with secondary consequences for Wnt and TGF-?? cascades. Upstream, IFT88 expression is regulated by RFX family transcription factors, FOXJ1, and inputs from Notch and Wnt pathways, highlighting its integration into broader gene regulatory networks.
In the 786-O renal carcinoma milieu, deletion of IFT88 creates a unique isogenic system for dissecting the tumor-suppressive or -promoting functions of cilia. While the VHL-deficient background drives pseudohypoxic and angiogenic phenotypes, the superimposed loss of IFT88 and primary cilia eliminates cilium-dependent Hedgehog modulation and may shift signal transduction toward non-canonical or cilia-independent pathways. Such alterations can influence proliferation, migration, and intracellular signaling, making these polyclonal knockout cells a powerful tool for mechanistic studies on how ciliary loss contributes to kidney cancer progression and for identifying therapeutic nodes that selectively target cilia-deficient tumors.
Researchers can apply the IFT88 Knockout 786-O Polyclonal Cells in diverse experimental workflows. Ciliary ablation is conveniently assessed by immunofluorescence microscopy using markers such as acetylated tubulin and ARL13B, while downstream Hedgehog pathway activity is quantified by RT-qPCR for GLI1 and PTCH1 transcripts. Western blotting of IFT88 and associated signaling components validates knockout efficiency and pathway perturbations. Phenotypic analyses such as cell proliferation and migration assays uncover functional consequences of IFT88 loss, and transcriptome-wide RNA-seq reveals global gene expression changes driven by ciliary dismantling. These applications position the model for investigations spanning ciliopathy research, polycystic kidney disease, short-rib polydactyly syndrome, and retinal degeneration, as well as drug discovery efforts aimed at renal cell carcinoma or other cilia-dependent malignancies. For additional details or technical support, please contact Ascent Research.
