The BRAF Knockout CAL-27 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population in which the BRAF gene is disrupted in the CAL-27 human tongue squamous cell carcinoma epithelial line. This loss-of-function model allows interrogation of BRAF-dependent signaling in an oral squamous cell carcinoma context. The polyclonal format comprises a heterogeneous mixture of edited cells, each with unique CRISPR-induced modifications, avoiding clonal bias and better representing tumor heterogeneity. The cells are supplied as a live stock for in vitro research.
CAL-27 was derived from a 56-year-old male with tongue squamous cell carcinoma and serves as a well-characterized model of oral cancer. These epithelial cells retain malignant features including invasive capacity and responsiveness to growth factor and oncogenic pathways. CAL-27 is widely used to study oral carcinogenesis, tumor progression, and drug responses, making it an ideal host for targeted genetic modifications such as BRAF knockout.
BRAF encodes a serine/threonine kinase acting as a critical node in the RAS-RAF-MEK-ERK (MAPK/ERK) signaling cascade. Upon receptor tyrosine kinase stimulation, RAS GTPases (HRAS, KRAS, NRAS) activate BRAF, which phosphorylates MEK1/2; MEK1/2 then phosphorylate ERK1/2. Nuclear ERK1/2 regulates transcription factors ELK1, MYC, and FOS to drive proliferation and survival gene programs. BRAF function is modulated by interacting partners including KSR1, 14-3-3 proteins, HSP90, and RAF1, and crosstalks with the PI3K/AKT pathway. Consequently, BRAF disruption blocks signal propagation from RAS to downstream MAPK/ERK effectors.
In oral squamous cell carcinoma, MAPK/ERK pathway activity often promotes tumor growth. Although activating BRAF mutations are infrequent in this cancer type, wild-type BRAF can contribute via overexpression or upstream oncogenic events. This BRAF knockout CAL-27 model enables dissection of wild-type BRAF??s role in tumorigenesis, exploration of synthetic lethal relationships, and investigation of resistance mechanisms to BRAF inhibitors such as vemurafenib. It thus provides a valuable tool for both fundamental signaling studies and translational oral oncology research.
Researchers can employ these polyclonal knockout cells in diverse applications. Western blotting for BRAF and phospho-ERK validates pathway disruption, while Sanger sequencing reveals the indel landscape. Functional assays including cell proliferation, colony formation, and tumorigenesis assays quantify the knockout phenotype. Drug sensitivity profiling with vemurafenib or other MAPK inhibitors assesses pathway dependency and identifies compensatory pathways. Additional uses include genome-wide screens and studies of invasive behavior. For further information or to acquire this product, please contact Ascent Research.
