A431 cells are a model cell line (epidermoid carcinoma) used in biomedical research.[1] More specifically, they are used in studies of the cell cycle and cancer-associated cell signalling pathways since they express abnormally high levels of the Epidermal growth factor receptor (EGFR). As such they are often used as a positive control for EGFR expression. They contain no functional p53, a potent tumor suppressor gene, and so are highly sensitive to mitogenic stimuli. A431 cells were established from an epidermoid carcinoma in the vulva of an 85 year old female patient.
Epidermal growth factor (EGF) stimulation of A431 cells induces rapid tyrosine phosphorylation of intracellular signalling proteins which control cellular processes such as growth, proliferation and apoptosis. At low (picomolar) concentrations EGF promotes cell growth of A431 cells whereas at higher (nanomolar) concentrations it inhibits growth by causing the cells to terminally differentiate. Treatment of A431 cells with bradykinin reduces basal and EGF-induced EGFR phosphorylation.[2] Treatment with sertoli cell secreted growth factor (SCSGF) strongly induces cell proliferation.[3][4] Stimulation of A431 cells with phorbol esters induces expression of interleukin 1-related protein IL1H.