Cancer‐associated fibroblasts predict poor outcome and promote periostin‐dependent invasion in oesophageal adenocarcinoma

Abstract

Interactions between cancer cells and cancer-associated fibroblasts (CAFs) play an important role in tumour development and progression. In this study we investigated the functional role of CAFs in oesophageal adenocarcinoma (EAC). We used immunochemistry to analyse a cohort of 183 EAC patients for CAF markers related to disease mortality. We characterized CAFs and normal oesophageal fibroblasts (NOFs) using western blotting, immunofluorescence and gel contraction. Transwell assays, 3D organotypic culture and xenograft models were used to examine the effects on EAC cell function and to dissect molecular mechanisms regulating invasion. Most EACs (93%) contained CAFs with a myofibroblastic (α-SMA-positive) phenotype, which correlated significantly with poor survival [p = 0.016; HR 7. 1 (1.7–29.4)]. Primary CAFs isolated from EACs have a contractile, myofibroblastic phenotype and promote EAC cell invasion in vitro (Transwell assays, p ≤ 0.05; organotypic culture, p < 0.001) and in vivo (p ≤ 0.05). In vitro, this pro-invasive effect is modulated through the matricellular protein periostin. Periostin is secreted by CAFs and acts as a ligand for EAC cell integrins αvβ3 and αvβ5, promoting activation of the PI3kinase–Akt pathway. In patient samples, periostin expression at the tumour cell–stromal interface correlates with poor overall and disease-free survival. Our study highlights the importance of the tumour stroma in EAC progression. Paracrine interaction between CAF-secreted periostin and EAC-expressed integrins results in PI3 kinase–Akt activation and increased tumour cell invasion. Most EACs contain a myofibroblastic CAF-rich stroma; this may explain the aggressive, highly infiltrative nature of the disease, and suggests that stromal targeting may produce therapeutic benefit in EAC patients.

Role of periostin in esophageal, gastric and colon cancer

“…At the same time, periostin was reported to bind as a ligand to αvβ3 and αvβ5 integrins ( Fig. 1), thus signaling via the PI3K-Akt pathway within oesophageal adenocarcinoma cells; this indicated that periostin accumulated to a higher degree in ESCC tissue than in adjacent tissue outside the tumor (15).…”

Periostin function in communication with extracellular matrices

“…Pathologically, periostin has also been localized in infarcted myocardium Oka et al 2007), fibrosis (Okamoto et al 2011;Ishikawa et al 2014;Naik et al 2012;Takayama et al 2006;Uchida et al 2012), tissues undergoing wound healing (Nishiyama et al 2011;Norris et al 2007;Ontsuka et al 2012;Zhou et al 2010), and cancer-associated stroma (Fukushima et al 2008;Kashima et al 2009;Kikuchi et al 2008Kikuchi et al , 2014Liu et al 2014;Nitsche et al 2016;Oskarsson and Massague 2012;Qin et al 2016;Ruan et al 2009;Sung et al 2016;Tian et al 2015;Underwood et al 2015;Wang and Ouyang 2012). Taken together, periostin expression is well correlated with tissue regeneration (Conway et al 2014).…”

Molecular mechanism underlying the tumor-promoting functions of carcinoma-associated fibroblasts

“…Activated CAFs specifically upregulate the expression of α-SMA, fibroblast-specific protein 1 (FSP-1/S100A4), NG2, platelet-derived growth factor receptor (PDGFR)-α/β [13], fibroblast activation protein (FAP) [14], uPA [15], periostin [16], tenascin-C (TN-C) [17], palladin [18], podoplanin [19], and natriuretic peptide B (NPPB) [5]. There also exist evidences that some molecules are specifically downregulated in CAFs, such as caveolin-1 [20] and laminin [21], while epithelial cell markers (cytokeratin) and endothelial cell markers (CD31) disappear.…”