Secretome profiling of oral squamous cell carcinoma-associated fibroblasts reveals organization and disassembly of extracellular matrix and collagen metabolic process signatures

Abstract

An important role has been attributed to cancerassociated fibroblasts (CAFs) in the tumorigenesis of oral squamous cell carcinoma (OSCC), the most common tumor of the oral cavity. Previous studies demonstrated that CAFsecreted molecules promote the proliferation and invasion of OSCC cells, inducing a more aggressive phenotype. In this study, we searched for differences in the secretome of CAFs and normal oral fibroblasts (NOF) using mass spectrometrybased proteomics and biological network analysis. Comparison of the secretome profiles revealed that upregulated proteins involved mainly in extracellular matrix organization and disassembly and collagen metabolism. Among the upregulated proteins were fibronectin type III domain-containing 1 (FNDC1), serpin peptidase inhibitor type 1 (SERPINE1), and stanniocalcin 2 (STC2), the upregulation of which was validated by quantitative PCR and ELISA in an independent set of CAF cell lines. The transition of transforming growth factor beta 1 (TGF-β1)-mediating NOFs into CAFs was accompanied by significant upregulation of FNDC1, SERPINE1, and STC2, confirming the participation of these proteins in the CAF-derived secretome. Type I collagen, the main constituent of the connective tissue, was also associated with several upregulated biological processes. The immunoexpression of type I collagen N-terminal propeptide (PINP) was significantly correlated in vivo with CAFs in the tumor front and was associated with significantly shortened survival of OSCC patients. Presence of CAFs in the tumor stroma was also an independent prognostic factor for OSCC disease-free survival. These results demonstrate the value of secretome profiling for evaluating the role of CAFs in the tumor microenvironment and identify potential novel therapeutic targets such as FNDC1, SERPINE1, and STC2. Furthermore, type I collagen expression by CAFs, represented by PINP levels, may be a prognostic marker of OSCC outcome.Electronic supplementary material The online version of this article

Clinicopathologic significance of ROCK2 expression in oral squamous cell carcinomas

“…The protumorigenic effects of CAF are related to the vast repertoire of secreted molecules, which can directly influence the behavior of cancer cells, stimulating proliferation, invasion, and metastasis. Some of the known molecules secreted by CAF include the stromal derived factor 1 (SDF‐1/CXCL12), activin A and matrix metalloproteases, some types of collagen and other extracellular matrix proteins such as fibronectin, and ROCK2 . Our findings in this study revealed ROCK2 positivity in both tumor and stroma cells, and a significant association between ROCK2 expression by tumor cells and the density of CAF was observed.…”

Clinicopathological significance of chemokine receptor (CCR1, CCR3, CCR4, CCR5, CCR7 and CXCR4) expression in head and neck squamous cell carcinomas

“…In our sample, CCR4 was corre- and tumour microenvironment components. 14,15 Neoplastic cells are in permanent interaction with the microenvironment and cells of the connective tissue, such as cancer-associated fibroblasts (CAF) and immune cells. Furthermore, malignant cells are capable to modify the structure of its cytoskeleton and to express membrane receptors that facilitate its interaction.…”

“…Additionally, treatment and prognosis of HNSCC are proposed according to the TNM stage, but nevertheless it has been observed that patients with the same TNM receiving similar therapeutic approaches have different evolution, evidencing that TNM is not always effective and new prognostic markers (adjuvants for TNM) are imperative in HNSCC. The aggressive features of HNSCC are dependent on the interactions between neoplastic cells and tumour microenvironment components . Neoplastic cells are in permanent interaction with the microenvironment and cells of the connective tissue, such as cancer‐associated fibroblasts (CAF) and immune cells.…”

Tenascin-C and fibronectin expression divide early stage tongue cancer into low- and high-risk groups

“…Carcinoma-associated fibroblasts (CAFs), which are identified by their intracellular α -SMA, are known predictors for poor prognosis in various malignancies (de Vlieghere et al , 2015), including OTSCC (Kellermann et al , 2007; Li et al , 2015; Bagordagis et al , 2016). However, CAFs are not prognostic indicators at early stage OTSCC (Almangush et al , 2014; Kelner et al , 2015), only in patient material of pooled stages, and at late stages when the variation in prognostic markers does not affect the choice of treatment so drastically, as more effective modalities are utilised in all cases.…”