The GUCY1A1 Knockout HCT 116 Polyclonal Cells are a CRISPR/Cas9-mediated polyclonal knockout population featuring disruption of the GUCY1A1 gene, which encodes the ??1 subunit of soluble guanylyl cyclase. Generated without single-cell cloning, this heterogeneous pool of HCT 116 cells harbors diverse loss-of-function alleles, providing a robust system for pooled genetic screens and signaling analyses while avoiding clonal artifacts. The cells are suitable for experimental designs requiring constitutive blockade of the nitric oxide?CcGMP axis.
The parental HCT 116 cell line is a widely used human colorectal carcinoma epithelial model with microsatellite instability-high (MSI-H) status, driven by a homozygous mutation in the mismatch repair gene MLH1. This hypermutator line exhibits rapid proliferation, invasive capacity in vitro, and tumorigenicity in xenograft models, establishing it as a standard platform for studying oncogenic signaling, drug responses, and colorectal tumorigenesis. Its colorectal origin provides a pathophysiologically relevant background for dissecting GUCY1A1-dependent processes.
GUCY1A1 encodes the ??1 subunit of soluble guanylyl cyclase (sGC), the principal receptor for nitric oxide (NO). NO binding to the sGC heme cofactor activates conversion of GTP to cyclic guanosine monophosphate (cGMP), which then stimulates cGMP-dependent protein kinase (PKG) and modulates phosphodiesterase 5 (PDE5), cyclic nucleotide-gated ion channels, and vasodilator-stimulated phosphoprotein (VASP). The sGC heterodimer (??1/??1) is regulated by upstream factors including carbon monoxide and the chaperone Hsp90, with local NO production by nitric oxide synthase (NOS) isoforms. Downstream, PKG phosphorylates targets controlling vascular smooth muscle contraction, platelet inhibition, and gene expression programs governing cell proliferation and apoptosis.
In the HCT 116 MSI-H background, GUCY1A1 knockout permits dissection of NO?CcGMP signaling contributions to colorectal cancer. MSI-H tumors frequently exhibit altered cGMP metabolism, and the NO?CsGC axis has been implicated in genotoxic stress responses, apoptosis resistance, and proliferation control in colon epithelium. By eliminating sGC-dependent cGMP production, this model isolates NO-driven, cGMP-independent phenotypes and enables study of interactions between sGC signaling and known oncogenic pathways, such as mutant KRAS and PI3K signaling, without confounding by sGC activity.
The GUCY1A1 Knockout HCT 116 Polyclonal Cells support mechanistic studies of NO?CcGMP signaling in colorectal cancer, drug screening for sGC modulators, and functional analysis of cGMP effectors. Standard assays include NO donor stimulation (SNAP, DEA/NONOate) followed by cGMP immunoassay, phospho-VASP detection, RT-qPCR for gene expression, and MTT/Annexin V for proliferation and apoptosis. Western blotting confirms GUCY1A1 loss. The polyclonal format is suited for pooled CRISPR screens and xenograft studies that preserve population heterogeneity. For lot-specific information or custom protocols, contact Ascent Research.
