The IL6ST Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population enabling functional studies of the IL6ST gene. This product provides a heterogeneous pool of NCI-H1975 cells carrying targeted disruptions in IL6ST, which encodes the gp130 signal-transducing receptor subunit. By abolishing gp130 expression, this model allows investigation of IL-6 family cytokine signaling without single-cell clonal bias. The polyclonal format preserves genetic diversity while ensuring loss-of-function across the population, suitable for robust, population-level analyses in lung adenocarcinoma research.
The NCI-H1975 host cell line is a human non-small cell lung adenocarcinoma model harboring both the L858R activating mutation and the T790M gatekeeper mutation in the EGFR gene, conferring resistance to first-generation EGFR tyrosine kinase inhibitors. This genetic background makes NCI-H1975 valuable for studying acquired resistance mechanisms and evaluating next-generation therapeutics. The cells exhibit epithelial morphology and retain key signaling dependencies relevant to tumor biology.
IL6ST encodes gp130, the common signal-transducing subunit for IL-6 family cytokines (IL-6, IL-11, LIF, OSM, CNTF, CT-1, CLCF1). Upon cytokine binding, gp130 forms complexes with ligand-specific alpha chains (IL6R, IL11R, LIFR, OSMR, CNTFR) and activates associated JAK1, JAK2, and TYK2 kinases. Phosphorylated gp130 recruits STAT3, leading to its JAK-mediated phosphorylation and transcription of targets such as SOCS3, Bcl-2, Cyclin D1, c-Myc, and VEGF. Gp130 also engages the MAPK/ERK cascade via SHP2/Gab1 and the PI3K/AKT pathway. Thus, IL6ST disruption abrogates these cytokine-driven proliferative, survival, and inflammatory signals.
In NCI-H1975 cells, gp130 signaling may intersect with EGFR-driven oncogenic pathways, potentially contributing to tumor cell survival and resistance to EGFR inhibitors. STAT3 activation through gp130 has been implicated in bypass mechanisms sustaining proliferation when EGFR is blocked. Eliminating IL6ST expression allows direct assessment of IL-6 family cytokines in therapeutic resistance and evaluation of dual pathway inhibition. This model also facilitates studies of paracrine and autocrine cytokine loops within the tumor microenvironment.
Applications include western blot analysis of IL-6-induced STAT3 phosphorylation, RT-qPCR quantification of SOCS3 and Bcl-2 transcripts, and cell proliferation assays with or without EGFR inhibitors. The polyclonal cells can be stimulated with gp130-utilizing cytokines to validate pathway inactivation and screen for small-molecule inhibitors. They are also suitable for co-culture experiments assessing immune modulation and cytokine release. This knockout model is a valuable tool for fundamental signal transduction and translational oncology studies. For further information, please contact Ascent Research.
