The HRH1 Knockout MCF-7 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population generated through targeted disruption of the HRH1 gene in MCF-7 cells. This polyclonal pool provides a genetically heterogeneous loss-of-function model, enabling robust dissection of histamine H1 receptor-mediated signaling without clonal selection artifacts. The knockout product format ensures broad representation of HRH1-disrupted alleles while maintaining the parental line??s epithelial phenotype and hormone responsiveness.
Derived from a pleural effusion of a breast adenocarcinoma patient, MCF-7 cells represent a well-characterized model of estrogen receptor-positive (ER+), luminal A subtype breast cancer. These adherent epithelial cells retain functional estrogen receptor signaling and hormone-dependent growth, making them a foundational system for studying ER+ tumor biology, endocrine therapy responses, and luminal-type breast cancer progression. The transcriptional and metabolic features of MCF-7 cells closely mirror those of low-grade, hormone-responsive clinical tumors.
Histamine H1 receptor (HRH1) encodes a Gq/11-coupled receptor that, upon activation by histamine, engages GNAQ/GNA11 to stimulate phospholipase C-beta (PLC-beta). This leads to generation of inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG), triggering IP3 receptor-mediated calcium release and protein kinase C (PKC) activation. Downstream, PKC and calcium fluxes activate the MAPK/ERK1/2 cascade and nuclear factor-kB (NF-kB), promoting expression of inflammatory mediators such as cyclooxygenase-2 (COX-2). Negative regulation involves G protein-coupled receptor kinases (GRK2/GRK5) and beta-arrestin2 (ARRB2), which mediate receptor desensitization. In the knockout cells, histamine-induced calcium mobilization and phospho-ERK1/2 induction are abolished, confirming loss of functional HRH1 signaling.
Disruption of HRH1 in an ER+ breast cancer background provides a powerful tool to investigate histamine-elicited inflammatory signaling within the context of luminal tumor biology. Histamine is present in the tumor microenvironment, potentially influencing breast cancer cell proliferation, migration, and invasion through HRH1. This polyclonal knockout model permits assessment of HRH1-dependent effects on epithelial-to-mesenchymal transition (EMT) markers, cytokine secretion profiles, and sensitivity to antihistamines or endocrine therapies, thereby illuminating crosstalk between mast cell-derived histamine and cancer cell behavior.
Typical applications include histamine dose-response calcium flux assays to verify loss of receptor function, quantitative RT-PCR and Western blotting for downstream targets (e.g., phospho-ERK1/2, NF-kB p65, COX-2), and NF-kB luciferase reporter gene assays. Functional studies such as wound-healing and transwell migration assays allow evaluation of HRH1??s role in histamine-modulated cell motility. This polyclonal cell population also supports drug screening for HRH1 antagonists or biased ligands, and co-culture experiments with mast cells or immune components to recapitulate inflammatory tumor niches. Researchers are invited to contact Ascent Research for further product specifications or customized experimental guidance.
