Tumor-associated fibroblasts expression in esophageal squamous cell carcinoma and may descend from mesenchymal stem cells

Abstract

Tumor-associated fibroblasts (TAFs) play a pivotal role in cancer proliferation, invasion and metastasis. The expression of TAFs in esophageal squamous cell carcinoma (ESCC) tissues remain unclear. We investigated the relevance of TAFs in ESCC, and then culture mesenchymal stem cells (MSC) by ESCC microenvironment induced their conversion into TAFs to assess whether MSC are precursors of TAFs. We detected the expression of TAFs surface markers, including α-SMA, and S100A4 in esophageal squamous cell cancer tissues by using immunohistochemistry, and evaluated associations with clinicopathological features. In order to verify whether MSC is one of the TAFs sources, we used culture supernatant from ESCC tumor cells to culture and induce MSC to transform into TAFs. TAFs surface markers, α-SMA and S100A4, were expressed in ESCC tissues, and their expressions correlated with tumor differentiation and clinical TNM stage. Real-time-PCR analysis and Western-Blot analysis confirmed MSC conversion into TAFs. Our study demonstrated that TAFs existence in esophageal carcinoma, and their expression was also closely related to metastasis and poor prognosis. Furthermore, we confirmed the conversion from MSC to TAFs and surmised MSC may be the precursors of TAFs.