The INSR Knockout CAL-27 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the insulin receptor (INSR) gene has been disrupted. This product provides a heterogeneous pool of CAL-27 cells harboring targeted gene disruptions, enabling loss-of-function studies of insulin receptor signaling in a human tongue squamous cell carcinoma background. The polyclonal nature retains cellular diversity and is well-suited for pooled functional assays and high-throughput screening applications where monoclonal isolation is not required.
CAL-27 is an adherent epithelial cell line derived from a squamous cell carcinoma of the tongue in a 56-year-old male patient. It is HPV-negative and widely employed as a model for oral squamous cell carcinoma (OSCC), a malignancy with increasing global incidence. CAL-27 cells exhibit characteristic epithelial morphology and have been extensively characterized for oncogenic signaling, drug responses, and metabolic studies. This cell line provides a relevant tumor context to investigate the role of insulin signaling in OSCC progression and therapy resistance.
The INSR gene encodes the insulin receptor, a transmembrane tyrosine kinase that mediates the cellular response to insulin, IGF1, and IGF2. Upon ligand binding, the receptor activates downstream adaptors such as IRS1 and Shc, initiating two major signaling cascades: the PI3K-Akt pathway, which promotes glucose uptake, metabolism, and survival, and the MAPK/ERK pathway, which drives proliferation and differentiation. The receptor interacts directly with IRS1, IRS2, Shc, and Grb2, and signals through PI3K, Akt, mTOR, ERK, and FOXO1. In the knockout model, disruption of INSR abrogates insulin-stimulated phosphorylation of IRS1 and subsequent activation of Akt and ERK, leading to impaired glucose uptake, reduced cell growth, and altered metabolic gene expression. This loss-of-function system enables precise dissection of insulin-dependent and -independent signals.
In the context of CAL-27 oral cancer cells, INSR knockout models clinically relevant insulin resistance and metabolic reprogramming. Oral tumors often exhibit altered insulin/IGF signaling, and this knockout allows investigation of tumor cell adaptation to nutrient stress, cross-talk with the IGF1 receptor, and sensitivity to PI3K or metabolic inhibitors. The model can recapitulate features of insulin receptoropathies such as Donohue syndrome and Rabson-Mendenhall syndrome, while also serving as a platform to study the intersection of metabolic and oncogenic pathways in HPV-negative OSCC.
Researchers can employ this polyclonal knockout population in a variety of assays to assess insulin signaling dynamics. Western blotting for INSR, phosphorylated Akt (Ser473), and phosphorylated ERK (Thr202/Tyr204) confirms target disruption and pathway inactivation. RT-qPCR quantifies residual INSR transcript levels. Functional readouts include 2-deoxyglucose uptake assays to measure glucose transport, MTT or BrdU proliferation assays, and Annexin V/PI apoptosis assays. Colony formation assays evaluate long-term growth potential, while metabolomics analyses reveal shifts in central carbon metabolism. Drug sensitivity testing with insulin, PI3K inhibitors (e.g., LY294002), or chemotherapeutics can uncover synthetic lethal interactions. Phospho-signaling arrays provide a broader view of pathway crosstalk. For further technical details and customization options, please contact Ascent Research.
