Ethanol exposure exacerbates 4-nitroquinoline-1-oxide induced esophageal carcinogenesis and induces invasive carcinoma with muscularis propria infiltration in a mouse model

Esophageal squamous cell carcinoma (ESCC) is one of the most fatal cancers worldwide. Most ESCC patients are diagnosed at an advanced stage; however, current research on in vivo animal models accurately reflecting their clinical presentation is lacking. Alcohol consumption is a major risk factor for ESCC and has been used in several disease models for disease induction. In this study, we used 4-nitroquinoline-1-oxide in combination with ethanol to induce an in vivo ESCC mouse model. Esophageal tissues were stained with hematoxylin and eosin for histopathological examination and lesion scoring. In cellular experiments, cell adhesion and migration invasion ability were observed using phalloidin staining, cell scratch and transwell assays, respectively, and the expression of epithelial-mesenchymal transition-related markers was detected using quantitative reverse transcription polymerase chain reaction and western blotting. The results showed that ethanol-exposed mice lost more weight and had an increased number of esophageal nodules. Histological examination revealed that the lesion scores of the ethanol-exposed esophageal samples were significantly higher than those of the unexposed esophageal samples. Furthermore, ethanol-exposed esophageal cancer samples had more severe lesions with infiltration of tumor cells into the muscularis propria. In vitro cellular experiments showed that ethanol exposure induced cytoskeletal microfilament formation, promoted cell migration invasion elevated the expression of N-cadherin and Snail, and decreased the expression of E-cadherin. In conclusion, ethanol exposure exacerbates ESCC, promotes tumor cell infiltration into the muscularis propria, and could be an effective agent for establishing innovative models of invasive carcinoma.