The HRH1 Knockout HT29 Polyclonal Cells represent a CRISPR/Cas9-mediated gene-disrupted population derived from the HT29 human colorectal adenocarcinoma cell line. This polyclonal knockout product ablates expression of the histamine H1 receptor (HRH1), generating a loss-of-function model for interrogating HRH1-dependent signaling in an intestinal epithelial tumor context. The pooled format retains the heterogeneous genetic background of HT29 cells, enabling robust, population-level analyses of histamine-receptor functions without clonal selection biases. Cells are supplied as a ready-to-use, edited population suitable for a wide range of downstream functional assays.
HT29 cells are a widely employed model of human colorectal adenocarcinoma, exhibiting epithelial morphology and retaining characteristics of intestinal epithelium. This cell line serves as a key tool in cancer biology, particularly for investigating colorectal tumorigenesis, drug transport, and intestinal barrier permeability. The HT29 background also supports studies of mucin production and differentiation, making it a versatile platform for examining receptor-mediated signaling in a malignant colonic environment.
The HRH1 gene encodes the histamine H1 receptor, a Gq/11 protein-coupled receptor that mediates allergic and inflammatory responses. Upon histamine binding, HRH1 activates G??q/11 subunits (GNAQ, GNA11), stimulating phospholipase C ?? (PLCB1) to generate inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 triggers calcium release from intracellular stores via IP3 receptors (IP3R), while DAG activates protein kinase C (PRKCA). Downstream, this cascade phosphorylates extracellular signal-regulated kinases (MAPK3/ERK1/2) and regulates transcription factors such as NF-??B (NFKB1) and c-Fos, leading to expression of inflammatory mediators like IL-8. The receptor also interacts with regulatory proteins including GRK2, ??-arrestin-1/2, and calmodulin, and is subject to negative regulation by the glucocorticoid receptor. HRH1 knockout eliminates histamine-induced Gq/11 coupling, abrogating PLC activation, calcium mobilization, and subsequent MAPK and NF-??B pathway engagement.
In the HT29 colorectal cancer context, HRH1 signaling has been implicated in tumor-associated inflammation and potential proliferative effects. Histamine levels are often elevated in the tumor microenvironment, and H1 receptor activation may contribute to cytokine secretion, cell migration, and survival pathways. By disrupting HRH1, this knockout model enables dissection of histamine’s contributions to colorectal cancer cell behavior, including inflammatory gene expression and crosstalk with immune-related signaling networks. It also provides a controlled system to evaluate the receptor’s role in intestinal epithelial responses to histamine, which may influence barrier function and tumor progression.
This product is ideally suited for a range of functional assays, including calcium flux measurements using Fluo-4 to quantify histamine-stimulated intracellular calcium release, RT-qPCR analysis of immediate-early genes (c-Fos) and cytokines (IL-8), and Western blotting for phospho-PKC and phospho-ERK1/2. Additional applications encompass histamine dose-response signaling studies, scratch-wound migration assays, MTS proliferation assays, and RNA-seq profiling of transcriptomic changes following receptor stimulation. ELISA-based quantification of secreted cytokines can further link HRH1 activity to inflammatory outputs. These tools support investigations into histamine signaling in colorectal cancer, pharmacological profiling of H1 antihistamines, and exploration of GPCR crosstalk in intestinal epithelial cells. For additional details or technical support, please contact Ascent Research.
