Mechanistic Insights and Clinical Implications of ELK1 in Solid Tumors: A Narrative Review

ELK1 is a Transcription factor (TF) belonging to the ETS-domain TF family, mainly activated via RAS-RAF-MEK-ERK signaling. As a nethermost pathway molecule, ELK1 binds to Serum-response elements (SREs) and directly regulates the transcription of Immediate early genes (IEGs) including FOS and EGR1. Due to ELK1's influence on key cellular processes such as proliferation, migration, apoptosis evasion, and Epithelial-to-mesenchymal transition (EMT), its role as a key contributor to tumorigenesis is emerging. In recent years, elevated expression and/or activation of ELK1 has been reported in various malignancies, including lung, breast, prostate, colorectal, blood, gastric, liver, cervical, thyroid and ovarian cancer. ELK1 acts primarily through direct DNA binding but also through interaction with other oncogenes, noncoding RNA molecules, TFs, and upstream kinases (other than ERK1/2), thus participating in diverse axes of transcriptional regulation. Its crucial role in IEG expression has been particularly implicated in cancer progression, metastasis, and drug resistance. Owing to its role in multiple cellular functions and its subsequent oncogenic potential, further elucidation of intracellular ELK1 interactions is of paramount importance. This review aims to summarize current evidence on ELK1's involvement in solid tumors, dissect reported mechanistic roles, and highlight recent insights that could fuel future ventures of high translational interest.