Exploring mast cell phenotype and functions during tumor progression

Introduction Mast cells (MCs) infiltrate both human and mouse colorectal cancer (CRC) lesions but their role in tumor progression is still controversial. The aim of this study is to identify the molecular players able to modulate MC phenotype and functions during CRC progression. Methods: An established murine model of colitis-induced colorectal cancer was employed to evaluate MC frequency and functions by flow cytometry and IHC. Biopsies from CRC patients and paraffin-embedded tissue sections were also analysed. Tumor microenvironment was analysed by ELISA and the role of SCF evaluated by in vivo depletion and in vitro studies. Results: We observed an increased frequency of MCs with a connective phenotype both in murine and human tumor masses. Murine CRC microenvironment is enriched of SCF that is responsible for shaping MC phenotype and cytokine production. Conclusion: In CRC, SCF activated-MCs produce high amounts of cytokines contributing to the establishment of a proinflammatory environment