# Elucidating key targets and mechanisms of diethyl phthalate-induced colorectal cancer through network toxicology and molecular docking

## TL;DR

This study explores how diethyl phthalate may contribute to colorectal cancer by identifying key molecular targets and mechanisms using network toxicology and molecular docking.

## Contribution

The study introduces a novel integration of network toxicology and molecular simulations to elucidate DEP's potential role in colorectal cancer.

## Key findings

- DEP showed moderate binding affinities with key epigenetic regulators like HDAC1, KDM1A, and EZH2.
- Molecular dynamics simulations revealed stable interactions between DEP and several CRC-related proteins.
- The findings highlight DEP's potential impact on cancer-related pathways such as Notch, TGF-β, and FoxO.

## Abstract

Diethyl phthalate (DEP), a widely used plasticizer with endocrine-disrupting properties, has raised concerns regarding its potential carcinogenic effects. However, its precise role in colorectal cancer (CRC) development remains poorly understood.

The chemical structure of DEP was obtained from the PubChem database. Potential targets of DEP were identified through ChEMBL and STITCH databases and intersected with known CRC-related genes to screen for candidate biomarkers. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to explore the biological functions and signaling pathways involved. Molecular docking was conducted to predict the binding affinities between DEP and core targets. Finally, 200-ns molecular dynamics (MD) simulations using GROMACS were employed to evaluate the binding stability and dynamic behavior of the DEP–target complexes.

A total of 62 overlapping genes were identified between DEP targets and CRC-associated genes. GO and KEGG enrichment analyses indicated enrichment in epigenetic regulation, chromatin remodeling, and cancer-related signaling pathways, including Notch, TGF-β, and FoxO. Protein–protein interaction analysis identified EP300, EZH2, HDAC1, HDAC2, and KDM1A as key epigenetic regulators. Molecular docking predicted moderate binding affinities between DEP and these targets (−6.6 to −5.7 kcal·mol ⁻ ¹). Subsequent 200-ns MD simulations suggested that DEP formed stable complexes with HDAC1, KDM1A, and EZH2, moderate stability with EP300, and partial dissociation with HDAC2, consistent with hydrophobic and hydrogen-bonding interactions at the binding interfaces.

This study provides a theoretical framework for exploring the molecular mechanisms through which DEP may contribute to CRC development, emphasizing the value of network toxicology in cancer research. These findings may inform future investigations into the risks of DEP exposure and support public health policy and the development of targeted therapeutic strategies.