Testis peritubular myoid cells increase their motility and express matrix-metalloproteinase 9 (MMP-9) after interaction with embryonal carcinoma cells

Today cancer research studies have highlighted the role of the cancer-stroma interaction in the regulation of invasive processes. However, very little is known about cell-to-cell relationships between germinal cancer cells and the somatic ones belong to their close environment, particularly at early invasion stages. Here, we have studied the potential role of the seminiferous peritubular myoid cells (PTCs), as potential part of the reactive stroma, like tumor myofibroblast, in the progression of embryonal carcinoma (EC). To this end, we show results on the in vitro interactions between F9 murine embryonal carcinoma cells (EC cells) and primary cultures of murine PTCs, using contact-dependent and contact-independent 2D co-cultures. In these circumstances, when EC cells interact with PTCs they change their migratory behavior and matrix-metalloproteinase 9 (MMP-9) was up-regulated in PTCs. Additionally, among a variety of cytokines implicated in tumor-stroma cross-talk, we have examined in more detail the influence of tumor necrosis factor alpha (TNF-alpha). In this regard, it was observed that this cytokine induced a MMP-9 secretion by PTCs in a pattern dependent on its concentration, whereas does not increase the migration capacity of cancer cells. All together, our results provide evidence for a role played by peritubular myoid cells and cancer-cell secreted TNF-alpha for a change in the tumor microenvironment during the early stages of EC progression.