Abstract 5085: Cancer-associated fibroblasts transcriptional pattern reveals common changes in extracellular matrix-related genes across different cancer types
Authors: Andriani Francesca , Giussani Marta , Facchinetti Federica , Callari Maurizio , Tagliabue Elda , Pastorino Ugo , Roz Luca , Sozzi Gabriella , Sozzi Gabriella 
Published: July 2016

Interactions between cancer cells and the surrounding microenvironment are crucial determinants of cancer progression. Fibroblasts isolated from carcinomas (cancer associated fibroblasts, CAF) have been shown to fuel the neoplastic process. While normal fibroblasts from different organs generally present very specific transcriptional programs, CAF from different tumors display a similar phenotype reminiscent of myofibroblasts found at sites of wound healing, indicating that common transcriptional programs could be induced by cancer cells on the surrounding microenvironment.

To investigate the existence of common mechanisms in fibroblast activation across different cancer types, gene expression profiles of tumor stroma or cancer associated fibroblasts (CAF) derived from breast, prostate and lung cancer were previously evaluated performing an inter-pathology bio-informatics analysis. For each comparison, genes were ranked and subjected to Gene Set Enrichment Analysis to identify Canonical Pathways significantly enriched. Most of commonly enriched gene sets were related to extracellular matrix (ECM) structure and remodeling, cytoskeletal organization and cell-cell adhesion. We specifically evaluated a previously identified ECM-related signature (ECM3) defining a breast cancer subtype likely to progress. We found that ECM3 signature was significantly enriched (p-value &lt; 0.05) in cancer associated fibroblasts compared to the normal counterpart across different pathologies supporting the implication of ECM-related genes in fibroblasts with activated status. Furthermore increased expression of some of the most ECM3 genes (COL10A1, COMP and COL11A1) was detected in fibroblasts co-cultured with breast cancer cells, both in cellular extracts and in the conditioned medium (CM), suggesting their potential importance as circulating markers for early detection and risk assessment. To explore the significance of ECM-related molecules also in lung, we finally selected some of enriched ECM3-related molecules in lung fibroblasts (SPARC, COL11A1, MMP11, FN1, COMP, COL10A1) and we evaluated their presence in the conditioned medium. The analysis showed that the ECM molecules could be detected in medium conditioned by lung fibroblasts and generally enriched in CAF_CM compared to NF_CM (SPARC p = 0.004, COMP p = 0.003, MMP11 p = 0.012). Interestingly, analysis of de-cellularized extracellular matrix showed that Fibronectin 1 (FN1) was preferentially deposited by CAFs compared to NFs (p = 0.003) denoting a possible role of this molecule in the modulation of extracellular matrix during tumor development and/or progression.

These findings support the hypothesis that identification of common factors responsible for proficient tumor-stroma cross-talk could be instrumental in novel strategies for risk assessment in different diseases.

Citation Format: Francesca Andriani, Marta Giussani, Federica Facchinetti, Maurizio Callari, Elda Tagliabue, Ugo Pastorino, Luca Roz, Gabriella Sozzi, Gabriella Sozzi. Cancer-associated fibroblasts transcriptional pattern reveals common changes in extracellular matrix-related genes across different cancer types. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5085.