This product consists of a CRISPR/Cas9-edited polyclonal knockout cell population of the GPSM1 gene in the NCI-H1975 human non-small cell lung cancer (NSCLC) cell line. The polyclonal format provides a heterogeneous pool of cells carrying a spectrum of disruptive edits, allowing robust evaluation of gene function without single-cell clonal selection bias. The cellular pool retains the parental line??s key characteristics while enabling loss-of-function studies relevant to G protein signaling, asymmetric cell division, and autophagy regulation.
The NCI-H1975 host cell line was established from the pleural effusion of a non-smoking female with lung adenocarcinoma. This line harbors activating EGFR L858R and resistance-conferring T790M mutations, rendering it insensitive to first- and second-generation EGFR tyrosine kinase inhibitors (TKIs). As a widely used model for acquired EGFR inhibitor resistance, NCI-H1975 cells exhibit epithelial morphology and maintain critical oncogenic signaling networks central to NSCLC progression.
GPSM1 encodes a guanine nucleotide dissociation inhibitor (GDI) that stabilizes the inactive GDP-bound state of G??i/o subunits, thereby negatively regulating G protein-coupled receptor (GPCR) signaling. The protein orchestrates mitotic spindle orientation during asymmetric cell division by recruiting NuMA and dynein through its interaction with GPSM2 (LGN) and Inscuteable. Independently, GPSM1 modulates autophagy by inhibiting mTORC1, leading to activation of ULK1 and ATG13, essential components of the autophagic initiation complex. Upstream signals including GPCR ligands such as lysophosphatidic acid (LPA) and stromal cell-derived factor-1 (SDF-1) engage this pathway, while RGS proteins act as co-regulators of G protein activity.
Disruption of GPSM1 in the EGFR-mutant NCI-H1975 background creates a powerful tool to dissect the crosstalk between G protein-dependent pathways and oncogenic tyrosine kinase signaling in drug-resistant NSCLC. This model is particularly suited to investigate how altered spindle orientation and autophagy flux contribute to tumor cell heterogeneity, metastatic potential, and therapeutic evasion. The combination of EGFR inhibitor resistance with GPSM1 loss enables systematic interrogation of cooperative mechanisms that sustain cancer stemness and survival under kinase inhibitor stress.
Researchers can employ these polyclonal knockout cells in diverse assays, including Western blotting to confirm loss of GPSM1 protein and downstream effectors such as mTORC1 and ULK1; co-immunoprecipitation to map protein?Cprotein interactions with G??i/o, GPSM2, and NuMA; immunofluorescence to assess mitotic spindle orientation defects; and cell migration/invasion experiments to evaluate metastatic behavior. Moreover, the cells are suitable for EGFR TKI sensitivity profiling and autophagy flux measurements using LC3 turnover under various pharmacological or genetic perturbations. For additional information or customized cell solutions, please contact Ascent Research.
