STAT3-Luc/EF1α-mCherry Reporter Cell Line - TE-1

STAT3 is a transcription factor in the JAK-STAT signaling cascade that links cytokine and growth factor inputs to gene programs controlling proliferation, survival, and immune evasion. In response to ligands such as IL-6, IL-10, OSM, and EGF, receptor-bound JAK kinases phosphorylate STAT3 on tyrosine 705; the modified protein dimerizes, moves into the nucleus, and binds GAS-like response elements to switch on downstream targets including BCL-2, MCL-1, MYC, CCND1, and EZH2. Constitutive STAT3 activity has been reported in esophageal squamous cell carcinoma, where it correlates with proliferation, invasion, and resistance to chemotherapy and radiotherapy. The STAT3-Luc/EF1α-mCherry Reporter Cell Line - TE-1 carries multiple STAT3 response elements upstream of a firefly luciferase gene in the TE-1 human esophageal squamous cell carcinoma background, so STAT3 transcriptional activity is read out directly as luminescence. An mCherry marker and a puromycin resistance cassette are expressed constitutively from the EF1α promoter, providing a red fluorescent signal that tracks cell density independently of pathway activity.

The line is used to measure STAT3 activation in esophageal cancer cells and to screen modulators of the JAK-STAT axis. The reporter supports work on natural products reported to act on STAT3 in ESCC, which targets the AP-1/IL-6/STAT3 axis in TE-1 cells, and on negative regulators of the pathway such as TGR5 agonists and SOCS proteins. It is also useful for studies of cisplatin and radiation resistance, where STAT3-driven survival genes blunt therapeutic response, and for validating RNAi or CRISPR knockouts of JAK1, JAK2, TYK2, or STAT3 itself. Because the mCherry channel is independent of the pathway, the line fits 96- or 384-well screening and avoids repeated transient transfection across doses and passages.