Abstract
Objectives
Epithelial Specific ETS-1 (ESE-1), also known as E74-Like Factor 3 (ELF3), belongs to the E26 transformation-specific transcription factor superfamily and is of great interest as a potential target for managing several types of cancer. The objectives of this study are to investigate whether ESE-1/ELF3 is a tumor suppressor and to identify dietary anti-cancer compound to activate ESE-1/ELF3 expression in human colon cancer model.
Methods
The formation of aberrant crypt foci (ACF) was examined in wild type and ESE-1/ELF3 knockout mice exposed to combination of azoxymethane (AOM) and dextran sulfate sodium (DSS). Stable human colon cancer cell lines expressing ESE-1/ELF3 were established and used for xenograft study and in vitro mechanistic studies. Many bioactive phytochemicals were screened based on the activation of ESE-1/ELF3 expression.
Results
ESE-1/ELF3 knockout in mice increased AOM-induced and DSS-promoted formation of ACF. Conversely, overexpression of ESE-1/ELF3 suppressed tumorigenicity in a xenograft mouse study and repressed anchorage-independent growth and migration/invasion in human colon cancer cells. Full length ESE-1/ELF3 localized abundantly in the nucleus, and internal deletion of nuclear localization sequence 2 (NLS2) reduced nuclear ESE-1/ELF3. Three lysine residues (318KKK320) in the NLS2 determine its nuclear localization. We identified epigallocatechin-3-gallate (EGCG) that acts as a transcriptional activator of ESE-1/ELF3 in human colon cancer cells.
Conclusions
These findings propose a novel and promising molecular target of dietary anti-cancer compounds for prevention of colon cancer.
Funding Sources
American Cancer Society.
Supporting Tables, Images and/or Graphs
Gene expression profiling of human colon cancer cells following inhibition of signal transduction by 17-allylamino-17-demethoxygeldanamycin, an inhibitor of the hsp90 molecular chaperone
