The HRH1 Knockout T-47D Polyclonal Cells product provides a heterogeneous population of CRISPR/Cas9-edited T-47D cells with targeted disruption of the HRH1 gene, encoding the histamine H1 receptor. This polyclonal knockout cell pool is designed to enable study of HRH1-dependent signaling in a relevant breast cancer cellular background. The loss-of-function model abolishes histamine-mediated Gq protein-coupled receptor signaling, offering a valuable tool for dissecting the role of histamine in tumor-associated inflammation and proliferation.
The parental T-47D cell line is an estrogen-responsive breast epithelial cancer cell line originally derived from a pleural effusion of an invasive ductal breast carcinoma. This widely used model retains hormone receptor expression and serves as a representative system for studying hormone-responsive breast cancer. Its well-characterized signaling pathways and robust response to histamine stimulation make it particularly suitable for investigating the crosstalk between hormonal and inflammatory networks in mammary tumorigenesis.
HRH1 encodes the histamine H1 receptor, a Gq protein-coupled receptor that, upon histamine binding, activates heterotrimeric G proteins GNAQ and GNA11. These in turn stimulate phospholipase C beta isoforms (PLCB1, PLCB2), leading to hydrolysis of phosphatidylinositol 4,5-bisphosphate into inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). IP3 triggers intracellular calcium release, while DAG activates protein kinase C alpha (PRKCA). Downstream, this cascade activates mitogen-activated protein kinases MAPK1/MAPK3 (ERK2/ERK1) and the NF-??B transcription factor complex (NFKB1/RELA), ultimately driving expression of pro-inflammatory and proliferative genes such as IL6, IL8, TNFA, and PTGS2.
Disruption of HRH1 in T-47D cells eliminates histamine-induced calcium mobilization and attenuates the activation of MAPK/ERK and NF-??B pathways, thereby impairing the production of cytokines and other mediators that contribute to an inflammatory tumor microenvironment. Because T-47D cells are responsive to estrogen, the HRH1 knockout model allows researchers to investigate potential interactions between histamine signaling and hormone-driven growth pathways. It also provides a platform to assess how abrogation of histamine receptor function affects breast cancer cell proliferation, survival, and migratory capacity in the context of estrogen receptor-positive disease.
Common experimental applications include histamine-induced calcium flux assays to confirm loss of receptor function, RT-qPCR and western blotting to quantify changes in downstream gene and protein expression (e.g., phospho-ERK, IL6, TNFA), NF-??B reporter gene assays, cell proliferation and migration studies, and immunofluorescence for PLC-beta translocation. These readouts support drug efficacy testing for anti-histamine therapies and exploration of histamine??s role in hormone-responsive breast cancer and allergic inflammation within the breast microenvironment. For additional information, including lot-specific characterization data and custom options, please contact Ascent Research.
