The GPR75 Knockout NCI-H1299 Polyclonal Cells are a polyclonal cell population generated by CRISPR/Cas9-mediated disruption of the GPR75 gene, providing a loss-of-function model for studying this orphan GPCR involved in energy homeostasis. This heterogeneous knockout population avoids clonal biases and leverages robust genome editing to eliminate functional gene expression.
The host cell line, NCI-H1299, is a widely utilized human non-small cell lung carcinoma epithelial line originally derived from a lymph node metastasis of a 43-year-old male. This p53-null line is a standard model for metastatic lung adenocarcinoma research, offering a well-characterized background for studying oncogenic signaling and drug responses. The NCI-H1299 cells exhibit robust growth properties and are amenable to a variety of transfection and selection methods, facilitating the generation of genetically modified derivatives such as this GPR75 knockout population.
GPR75 encodes an orphan G protein-coupled receptor that couples to heterotrimeric G proteins G??s and G??q, triggering adenylyl cyclase and phospholipase C activation, respectively. These effectors generate second messengers cAMP and inositol trisphosphate (IP3), which activate protein kinase A (PKA) and protein kinase C (PKC). Downstream, PKA and PKC phosphorylate transcription factors CREB and NFAT, modulating gene expression. In hypothalamic neurons, GPR75 signaling regulates neuropeptide genes POMC and AgRP, controlling appetite and energy balance; GPR75 knockout reduces adiposity and protects against diet-induced obesity. Receptor interactions with ??-arrestins and receptor activity-modifying proteins (RAMPs) may modulate signaling, while upstream regulation involves unidentified endogenous ligands and possible metabolic hormones like leptin.
Within the NCI-H1299 lung cancer background, this knockout model enables study of GPR75 signaling in an epithelial tumor context, potentially distinct from neurons. Its expression in lung cancer cells remains poorly characterized, making it valuable for off-target analysis and exploring non-canonical roles. The p53-null status allows examination of crosstalk with p53-dependent processes like proliferation and apoptosis.
Typical research applications include functional characterization via siRNA rescue, validation of small-molecule GPR75 modulators for obesity and diabetes, and GPCR signaling dissection using cAMP and calcium assays. The cells support transcriptome analysis by RNA-seq and phenotypic assays like proliferation and migration, relevant to metabolic and cancer studies. Western blotting and RT-qPCR confirm gene disruption and assess changes in factors such as CREB, NFAT, and neuropeptide transcripts. For further information, contact Ascent Research.
