ETS-related transcription factor Elf-3 (ELF3) (ELF3)

ETS-related transcription factor Elf-3 (ELF3), also known as Epithelial-restricted with serine box (ESX), is an Ets-family transcription factor exclusively expressed in terminally differentiated epithelial tissues, such as the mammary gland, colon, and skin [3, 6]. It acts as a master regulator of epithelial cell differentiation and is a critical downstream effector in the HER2/neu (ERBB2) signaling pathway [5, 13]. In oncogenic contexts, ESX is frequently overexpressed or amplified in breast, lung, and head and neck squamous cell carcinomas (HNSCC), where it transactivates the promoters of growth factor receptors like EGFR and HER2 [1, 10, 15]. This transcriptional activation drives an invasive and transformed phenotype, facilitating tumor motility and survival [1, 5, 17]. Therapeutic strategies include small molecule inhibitors like wrenchnolol and biphenyl isoxazolidine, which disrupt the association of the ESX activation domain with its coactivator MED23 (Sur-2), thereby reducing oncogenic receptor levels and sensitizing tumors to tyrosine kinase inhibitors [1, 2, 18]. Despite its potential as a therapeutic target, challenging factors include the poor druggability of transcription factors and the risk of adverse effects on normal epithelial homeostasis [1, 11].

Other names

Epithelial-restricted with serine boxESXE74-like factor 3Epithelium-specific Ets transcription factor 1ESE-1E74-like ETS transcription factor 3ERTJENEPR-1

Small molecule inhibitors disrupt the interaction between the ESX activation domain and its transcriptional coactivators (such as the Mediator subunit MED23/Sur-2) or inhibit its DNA-binding activity, leading to the downregulation of downstream oncogenic targets like EGFR and HER2.