PAI-1 derived from cancer-associated fibroblasts in esophageal squamous cell carcinoma promotes the invasion of cancer cells and the migration of macrophages

Abstract

Cancer-associated fibroblasts (CAFs) contribute to the progression of various cancers. Previously, we reported the significance of CAFs in esophageal squamous cell carcinoma (ESCC); however, the functions of CAFs in the ESCC microenvironment remain unknown. To investigate CAFs’ function, we established an indirect coculture assay between human bone marrow-derived mesenchymal stem cells (MSCs) and ESCC cells. Cocultured MSCs expressed more fibroblast activation protein, one of the markers of CAFs, compared with monocultured MSCs. Therefore, we defined cocultured MSCs as CAF-like cells. To identify molecules associated with the ESCC progression in CAFs, we conducted a cDNA microarray analysis on monocultured MSCs and CAF-like cells to compare their gene expression profiles. We found that SERPINE1, which encodes plasminogen activator inhibitor-1 (PAI-1), was more abundant in CAF-like cells than in monocultured MSCs, and the PAI-1 derived from CAF-like cells induced the abilities of migration and invasion in both ESCC cells and macrophages by the Akt and Erk1/2 signaling pathways via the low-density lipoprotein receptor-related protein 1 (LRP1), which is a PAI-1 receptor. Based on immunohistochemistry assays of ESCC tissues, higher expression levels of PAI-1 and LRP1 were correlated with poor prognosis in ESCC patients. These results suggest that the PAI-1/LRP1 axis contributes to the progression of ESCC, making it a potential target for ESCC therapy.

Metallothionein 2A Expression in Cancer-Associated Fibroblasts and Cancer Cells Promotes Esophageal Squamous Cell Carcinoma Progression

“…To explore the role of CAFs in the ESCC tumor microenvironment, we established MSC-derived CAF-like cells by indirect co-culture of MSCs with ESCC cells. In a previous study, we compared MSCs and CAF-like cells by cDNA microarray analysis and found that, in the CAF-like cells, MT2A was the most upregulated among the differentially expressed genes [17]. Here, qRT-PCR and Western blotting confirmed that the MT2A mRNA and MT2A protein were highly expressed in all the three types of CAF-like cells (CAF8, CAF9, and CAF15) (Figures 1A,B and S8A).…”

“…In our previous study, the three types of CAF-like cells (CAF8, CAF9, and CAF15) enhanced the migration and invasiveness of three types of ESCC cell lines (TE-8, TE-9, and TE-15, respectively) [17]. In this study, we found that while MSCs also enhance the migration and invasiveness of the ESCC cell lines, the effects of CAF-like cells exceed those of MSCs (Figure 3A,B).…”

“…Additionally, the CAF-like cells promoted migration and invasion by ESCC cells and induced migration and TAM-like polarization of macrophages [16]. Our cDNA microarray analysis suggested that plasminogen activator inhibitor-1 (PAI-1) promoted the CAF-like cell-induced migration and invasion by ESCC cells and macrophages through the activation of Akt and Erk signaling via LDL receptorrelated protein 1 (LRP1) [17]. The CAF-like cells also highly expressed IL-6 and CCL2 by cDNA microarray analysis [17].…”

“…Our cDNA microarray analysis suggested that plasminogen activator inhibitor-1 (PAI-1) promoted the CAF-like cell-induced migration and invasion by ESCC cells and macrophages through the activation of Akt and Erk signaling via LDL receptorrelated protein 1 (LRP1) [17]. The CAF-like cells also highly expressed IL-6 and CCL2 by cDNA microarray analysis [17]. The role of IL-6 and CCL-2 in tumor progression was also demonstrated by Qin et al and Tsuyada et al, respectively [18,19].…”

Immune-Related Gene SERPINE1 Is a Novel Biomarker for Diffuse Lower-Grade Gliomas via Large-Scale Analysis

“…Moreover, there was initial evidence suggesting that PAI-1 can affect the biological behavior of inflammatory cells. For example, Sakamoto et al (58) found that PAI-1 that abnormally elevated in esophageal squamous cell carcinoma (ESCC) could promote macrophage infiltration by the Akt and Erk1/2 signaling pathways. And studies indicated that PAI-1 could assist IL-8-mediated neutrophil infiltration via inhibiting IL-8/Heparan Sulfate/ Syndecan-1 Complex shedding on endothelial cell surfaces (59).…”