Abstract 1545: Cytokine profiling of drug-disrupted tumor cell/fibroblast crosstalk provides insights to understand the protective role of the stroma
Authors: Guillen Díaz-Maroto Natalia , Gonçalves Samuel , Salazar Ramon , Carpentier Flavien , Mennesson Eric , Normand Nadia , Garcia Mollevi David 
Published: August 2015

Abstract
Background: The knowledge of which factors mediate the crosstalk between tumor cells and fibroblasts (most abundant stromal cell type) and how this cytokine repertoire is modulated by cancer therapy might provide insights to fight the disease. We used cytokine arrays in order to determine: i) cytokine profiling of IL1beta-treated normal colonic fibroblast (NCF) and ii) cytokine profiling of tumor cell-NCF cocultures in the presence of inhibitors of IL1beta and TGFbeta1 signaling, main triggers of fibroblast activation.
Methods: Conditioned media (CM) from NCF, IL1beta-treated NCF (10ng/ml) and IL1beta-treated NCF + neutralizing IL1beta antibody (10 μg/ml) was obtained after 24 hours in culture in FBS-free conditions. We evaluated the composition of CM obtained from cocultures between tumor cells and NCF in conditions where the crosstalk is disrupted with IL1beta blocking antibody (2 μg/ml) and an ALK5 inhibitor (0.1 μM). In both experiments we interrogated 174 cytokines/growth factors in glass-slide based arrays using fluorescent signal readout.
Results: We obtained CM from different NCF alone, or IL1beta-treated NCF or IL1beta-treated + blocking IL1beta antibody. Thus, we hybridized the CM in a Sandwich-ELISA based cytokine array interrogating 174 proteins. 43 out of 174 soluble factors were IL1beta-responsive products and controlled by the addition of the blocking antibody. Other 4 molecules were also IL1beta-responsive but were not controlled by the blocking antibody (BMP-7, Tie-2, IGF-2 and VGFR3). Functional assays revealed that IL1beta-treated fibroblasts CM induce migration and chemoprotection of tumor cells and this effect can be reverted with a blocking IL1beta antibody.
On the other hand, we evaluated the cytokine profile of the crosstalk between NCF and tumor cells considering the blockade of the two main triggers of fibroblast activation: coculture, coculture + IL1beta blocking antibody, coculture + ALK5 inhibitor or coculture + IL1beta blocking antibody + ALK5 inhibitor. 23 out of 174 factors were altered showing decreased concentration from coculture alone to coculture with the two blocking agents. Some of these factors are MMP1, EGF, KITLG or CXCL10. But surprisingly, 34 factors were progressively upregulated. Some of these factors were HGF, IL6, IL11, IL17, CCL8 or IL2RG.
Conclusions: Here we show an example of the usefulness of cytokine profiling as a complementary approach for microenvironment studies in assessing reciprocal activation of tumor cells and stroma, mediators of such interplay, treatment effectiveness and new target interventions.
Citation Format: Natalia Guillen Díaz-Maroto, Samuel Gonçalves, Ramon Salazar, Flavien Carpentier, Eric Mennesson, Nadia Normand, David Garcia Mollevi. Cytokine profiling of drug-disrupted tumor cell/fibroblast crosstalk provides insights to understand the protective role of the stroma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1545. doi:10.1158/1538-7445.AM2015-1545