ABSTRACTS – ORAL PRESENTATIONS - AMCA, spol. s r.o.

effects will be also characterized upon MSC coimplantation with the tumor cells in vivo
in the future. (Fig. 1).
Figure 1. Experimental design and the outcomes to be evaluated in the process of
tumor cell-driven MSC differentiation.
Results: Our data previously documented both tumor-promoting and tumor-suppressive
effects of MSC on different human tumor cells both in vitro and in vivo. Human melanoma
cells A375 represented the promoting features and induced expression of VEGFR2,
FSP, vimentin, αSMA and endosialin in MSC, which were indicative of differentiation
towards carcinoma-associated fibroblasts. Human glioblastoma cells 8-MG-BA
represented the inhibitory features and did not upregulate these proteins. On the
contrary, paracrine stimulation with these cells led to upregulation of genes involved in
adipocyte differentiation leading to the idea, that these cells promote aberrant terminal
differentiation of MSC with the tumor-suppressive outcome. Several surface markers
characteristic for the MSC were evaluated and multiple changes in CD73, CD90, CD105,
CD133, CXCR4, CD166, CD146, BCRPI, HLA-DR, CD44, CD31 and CD34 III were detected.
Tumor cells also affected migratory properties of MSC and altered the secretome profile
of the treated MSC. Many proinflamatory cytokines were upregulated significantly by
incubation in the A375-conditioned medium, including VEGF secretion and VEGFR2
expression.
Conclusion: Our data attempted to contribute to the understanding of tumor biology by
unraveling mechanisms involved in tumor-driven effects on non-neoplastic stromal cells.
74 Analytical Cytometry VII