环境污染物二甲基二异丁基苯（DINCH）通过上调NEDD1蛋白的表达，促进肝细胞癌的进展和上皮间质转化（EMT）进程。

Abstract

Background Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), a phthalate substitute widely detected in environmental and biological samples, has raised growing concerns regarding its potential health risks. However, its role in the pathogenesis and progression of hepatocellular carcinoma (HCC), particularly in epithelial–mesenchymal transition (EMT), remains largely unknown. Methods The effects of DINCH on HCC cells (LM3, Huh7) and immortalized normal hepatocytes (THLE-2) were assessed by evaluating proliferation (CCK-8, colony formation, and EdU assays), migration (wound healing and Transwell assays), EMT marker expression by Western blotting, and chemokine/cytokine secretion by ELISA. Bioinformatic analyses, including LASSO regression and immune infiltration profiling of the TCGA cohort, were performed to identify DINCH-related genes. Functional assays were combined with genetic manipulation of neural precursor cell expressed, developmentally down-regulated protein 1 (NEDD1), including knockdown and overexpression experiments, to elucidate its regulatory role. Results DINCH significantly promoted HCC cell proliferation and migration, accompanied by enhanced EMT characterized by decreased E-cadherin expression and increased N-cadherin, Vimentin, SNAI2, and ZEB1 expression. Notably, immortalized normal THLE-2 hepatocytes exhibited similar pro-tumorigenic responses to DINCH exposure, indicating that DINCH-induced oncogenic effects extend to non-malignant hepatocytes. Long-term, low-dose exposure experiments confirmed that even sub-micromolar DINCH concentrations promoted cell proliferation in both HCC cells and THLE-2 hepatocytes. A risk score model based on DINCH-related genes was constructed, and the high-risk group was associated with an immunosuppressive tumor microenvironment characterized by increased infiltration of Tregs and M2 macrophages. Integrative analyses identified NEDD1 as a key DINCH-associated candidate gene. Molecular docking suggested a potenti