The GPRC5A Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited human cell population enabling loss-of-function studies of the GPRC5A gene. This polyclonal knockout model is established in the HAP1 cell line, a near-haploid line widely used in functional genomics and knockout screens. The heterogeneous pool of cells carries diverse CRISPR/Cas9-mediated disruptions in the GPRC5A locus, facilitating robust population-level analysis of gene function. This tool is well-suited for investigating GPRC5A’s tumor-suppressive roles and dissecting its signaling networks.
HAP1 is a human near-haploid cell line derived from the KBM-7 chronic myeloid leukemia line. It maintains a haploid karyotype across all chromosomes except chromosome 8 and exhibits adherent fibroblast-like morphology. The near-haploidy simplifies gene disruption and genetic analysis, making HAP1 an ideal host for CRISPR-based knockout models. It is extensively used in genome-wide screens and mechanistic studies of oncogenic and tumor-suppressive pathways.
GPRC5A (G protein-coupled receptor class C group 5 member A) is an orphan GPCR induced by all-trans retinoic acid (ATRA) via retinoic acid receptors (RAR/RXR). It acts as a tumor suppressor by negatively regulating EGFR, NF-??B, and Stat3 signaling. Mechanistically, GPRC5A interacts with EGFR and ??-arrestin2, driving EGFR degradation and dampening downstream AKT and MAPK cascades. It also suppresses NF-??B activity by stabilizing I??B and reduces Stat3 phosphorylation, thereby inhibiting pro-survival and proliferative signals. Additionally, GPRC5A modulates cAMP/PKA and Wnt/??-catenin pathways, affecting expression of p21, p27, and cyclin D1.
In HAP1 cells, GPRC5A knockout provides a clean genetic background to dissect its tumor-suppressive mechanisms. Loss of GPRC5A in this near-haploid context allows systematic evaluation of EGFR stability, NF-??B transcriptional activity, and Stat3 signaling without diploid genome complexity. The polyclonal nature is advantageous for pooled screening applications such as drug sensitivity assays and synthetic lethality screens, where heterogeneous knockout effects can be assessed. Given its relevance to lung, oral, pancreatic, and other cancers, this model supports translational research.
This polyclonal knockout population supports functional genomics, cancer signaling studies, and drug sensitivity screening. Typical assays include Western blotting for GPRC5A and phospho-EGFR/phospho-Stat3, EGFR degradation assays, NF-??B luciferase reporters, cell proliferation (MTS/MTT) and apoptosis (Annexin V) analyses, and immunofluorescence. It is also suitable for GPCR pharmacology, de-orphanization, and identifying synthetic lethal interactions. For further technical information, please contact Ascent Research.
