Twist1 is highly expressed in cancer-associated fibroblasts of esophageal squamous cell carcinoma with a prognostic significance

Cancer-associated fibroblasts (CAFs) play important roles in cancer progression. Twist1 was recently reported to be a key regulator of CAFs in gastric cancer, but its role in other types of cancer remains unclear, especially for esophageal squamous cell carcinoma (ESCC). We assessed the Twist1 expression on stromal fibroblasts using immunohistochemistry in 169 tissue specimens from ESCC patients, and performed in vitro and in vivo experiments to confirm the role of Twist1 in CAFs of ESCC. And we investigated the biological pathways that are activated in Twist1-high ESCC using The Cancer Genome Atlas (TCGA) data. The expression of Twist1 in stromal fibroblasts was observed in 89.9% of ESCC patients and positively associated with the increased depth of tumor invasion, lymph node metastasis, and advanced clinical stage, and a significant adverse prognostic factor in overall survival. Twist1-expressing stromal fibroblasts also expressed representative CAF markers, and co-localization of Twist1 and CAF markers were confirmed by confocal immunofluorescence imaging. Bioinformatic analysis of mRNA expression data of esophageal cancer from TCGA revealed that gene sets of CAFs were highly enriched in Twist1-high ESCC. Depletion of Twist1 in ex vivo cultured ESCC CAFs induced significant decrease in migration, invasion, colony formation, sphere formation, and contractibility of ESCC cancer cells compared to control CAFs. Furthermore, Twist1-expressing fibroblasts remarkably enhanced the in vivo tumorigenicity of ESCC in a xenograft model. In conclusion, Twist1 could be a novel CAF marker for the prognostic evaluation of ESCC patients as well as a potent therapeutic target for ESCC.