The CBL Knockout NCI-H1299 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1299 human non-small cell lung carcinoma cell line. This polyclonal pool carries targeted disruption of the CBL gene, generating a loss-of-function model that eliminates CBL protein expression and its E3 ubiquitin ligase activity. The heterogeneous editing events across the cell population provide a robust system to study CBL-dependent processes without clonal artifacts. This product is supplied as a ready-to-use polyclonal knockout cell population, optimized for immediate in vitro experimentation.
The NCI-H1299 host cell line is a widely used model of lung adenocarcinoma, originally isolated from a lymph node metastasis of a non-small cell lung cancer patient. These epithelial cells are p53 null, rendering them deficient in the tumor suppressor p53 and recapitulating a common genetic alteration in aggressive lung cancers. The NCI-H1299 cell line exhibits anchorage-independent growth and tumorigenicity in vivo, making it a relevant platform for investigating oncogenic signaling, metastasis, and therapeutic resistance. Its epithelial origin and metastatic derivation provide a clinically pertinent context for evaluating gene function in cancer progression.
CBL encodes an E3 ubiquitin-protein ligase that functions as a critical negative regulator of receptor tyrosine kinase (RTK) signaling. CBL is recruited to activated RTKs??such as EGFR, MET, and PDGFR??via its SH2 domain-mediated interaction with phosphotyrosine residues or through adaptor proteins including GRB2 and CRK. Once bound, CBL, in cooperation with ubiquitin-conjugating enzymes (E2), catalyzes the polyubiquitination of the receptor, tagging it for proteasomal degradation. This ubiquitin-mediated attenuation of RTK signaling dampens downstream cascades like the MAPK and PI3K-AKT pathways. Upstream activation of CBL is regulated by SRC family kinases and phosphorylation events, while its activity directly targets EGFR, MET, and PDGFR for ubiquitin-proteasome degradation, thereby reducing proliferative and survival outputs.
In the context of the p53-null NCI-H1299 lung adenocarcinoma background, CBL knockout is expected to exacerbate RTK-driven oncogenic signaling. Loss of CBL-mediated receptor downregulation leads to sustained activation of EGFR, MET, and PDGFR, perpetuating MAPK and PI3K-AKT pathway stimulation. This mimics a state of chronic growth factor signaling, promoting cell proliferation, survival, and potentially invasion. Given the frequent dysregulation of EGFR and MET in non-small cell lung cancer, this knockout model is particularly relevant for dissecting mechanisms of targeted therapy resistance and for identifying vulnerabilities in tumors relying on aberrant RTK signaling.
Researchers can employ the CBL Knockout NCI-H1299 Polyclonal Cells in a diverse array of experimental workflows. Common applications include investigating the role of CBL in receptor tyrosine kinase degradation using EGFR degradation assays, assessing cell proliferation via MTT or BrdU incorporation, and evaluating invasive potential through Matrigel invasion assays. The polyclonal population is also suitable for studying drug sensitivity to EGFR and MET inhibitors, exploring ubiquitin-proteasome system function, and examining signaling dynamics by Western blotting for phospho-EGFR and downstream effectors. Gene expression analysis by RT-qPCR for CBL and target genes further complements functional studies. For additional details or custom requests, please contact Ascent Research.
