Interactions of human MSC with head and neck squamous cell carcinoma cell line PCI-13 reduce markers of epithelia-mesenchymal transition.

Objectives: Cancer progression is influenced by tumor microenvironment and communication of stromal cells and tumor cells. Interactions may enhance epithelial-mesenchymal transition (EMT) of tumor cells through signaling proteins such as Wnt/beta-catenin and matrix metalloproteinases (MMP), as well as loss of cellular integrity, which affects invasion, progression, and metastasis of head and neck squamous cell carcinoma (HNSCC). In this study, we are testing the hypothesis that interactions of human mesenchymal stromal cells (MSCs) with HNSCC might influence the expression of markers of EMT and tumor progression by co-culturing human MSC with the PCI-13 HNSCC line. Materials and methods: Pooled MSCs were derived from the iliac bone marrow of seven patients and co-cultured in transwell permeable membrane wells with tumor cells of the established HNSCC cell line PCI-13 (UICC: T3, N1, M0). MSCs were characterized through fluorescence-activated cell sorting (FACS) analysis. Expression of Wnt3, E-cadherin, beta-catenin, MMP14, cathepsin b, and ETS1 was assessed by quantitative RT-PCR. Results: We were able to show that co-culture of MSCs and PCI-13 leads to a significantly reduced expression of Wnt3, MMP14, and beta-catenin compared to controls, whereas the expression of cathepsin b and ETS1 was not significantly different between co-cultures and controls. Conclusion: Our results suggest that the interaction between MSCs and PCI-13 may suppress EMT in cancer cells. Clinical relevance: The influence of MSCs can suppress the onset of EMT in HNSCC, affecting tumor progression and therapy. [ABSTRACT FROM AUTHOR]