Cancer-associated fibroblasts (CAFs) contribute to the progression of various cancers. Previously, we reported thesignificance of CAFs in esophageal squamous cell carcinoma (ESCC); however, the functions of CAFs in the ESCCmicroenvironment remain unknown. To investigate CAFs’ function, we established an indirect coculture assay betweenhuman bone marrow-derived mesenchymal stem cells (MSCs) and ESCC cells. Cocultured MSCs expressed more fibroblastactivation protein, one of the markers of CAFs, compared with monocultured MSCs. Therefore, we defined coculturedMSCs as CAF-like cells. To identify molecules associated with the ESCC progression in CAFs, we conducted a cDNAmicroarray analysis on monocultured MSCs and CAF-like cells to compare their gene expression profiles. We found thatSERPINE1, which encodes plasminogen activator inhibitor-1 (PAI-1), was more abundant in CAF-like cells than inmonocultured MSCs, and the PAI-1 derived from CAF-like cells induced the abilities of migration and invasion in bothESCC cells and macrophages by the Akt and Erk1/2 signaling pathways via the low-density lipoprotein receptor-relatedprotein 1 (LRP1), which is a PAI-1 receptor. Based on immunohistochemistry assays of ESCC tissues, higher expressionlevels of PAI-1 and LRP1 were correlated with poor prognosis in ESCC patients. These results suggest that the PAI-1/LRP1axis contributes to the progression of ESCC, making it a potential target for ESCC therapy