AP1-Luc/EF1α-mCherry Reporter Cell Line - TE-1

AP-1 (Activator Protein 1) is a dimeric transcription factor composed of proteins from the Jun and Fos families, situated at the convergence of the MAPK, JNK, and EGFR signaling pathways. Upon activation, it regulates genes involved in cell proliferation, stress responses, and extracellular matrix remodeling. In esophageal squamous cell carcinoma (ESCC), AP-1 activity is frequently elevated and is closely linked to the production of IL-6, the expression of MMP-9, and the process of epithelial-mesenchymal transition (EMT). The AP1-Luc/EF1α-mCherry reporter cell line (TE-1) is derived from the human ESCC cell line TE-1 and incorporates multiple AP-1 response elements upstream of a firefly luciferase gene. The cell line also constitutively expresses the mCherry marker and a puromycin resistance gene under the control of an EF1α promoter, generating a stable red fluorescent signal. This signal allows researchers to normalize for variations in cell number and well-to-well differences without the need for separate cell viability assays.

This cell line is primarily used to measure changes in AP-1 transcriptional activity in esophageal cancer cells following stimulation or treatment with inhibitors. Typical experiments include evaluating the ability of natural products (such as isoliquiritigenin or matrine) and inhibitors of the EGFR or MAPK pathways to suppress AP-1-mediated transcription, as well as investigating whether the knockdown of upstream receptors—such as EGFR—attenuates this response. Furthermore, the cell line can be employed to study how radiation, oxidative stress, or inflammatory signaling activates AP-1, thereby promoting EMT or invasiveness in TE-1 cells. Additionally, given that AP-1 directly regulates the transcription of IL-6, the system can be used to explore the interplay between AP-1 and the IL-6/JAK/STAT3 signaling axis. Because the mCherry channel serves as an internal reference, this reporter system is highly suitable for screening assays in 96-well or 384-well plate formats, where luciferase assay readings typically require normalization based on cell density.