[Cells of endothelial lineage (or endothelial-like cells) as possible progenitor cells of sarcomas induced by implanted foreign body].

: This study is dedicated to the problem of the origin of progenitor cells of sarcomas induced by implantation of a foreign body (polyvinilchloride plates) to mice. It is known that such cells are found among the cells of the monolayer covering the surface of implanted plate without any signs of tumor growth in 6 and more months after implantation. We studied the existence of endothelial features of mesenchymal type cells that had been grown by culturing the cells from the implanted plate surface in 9 and 14 months after implantation. We have shown that these cells are really the precursors of FB sarcomas thou they had different tumor potential depending on the period since implantation moment. We studied the behavior of these pretumor cells in 2D (on plastic) and 3D (on matrigel) cultures. We have found that in the case of a dense monolayer on plastic such cells show growth of endothelial type (cobblestone). When sown on matrigel they are organized in more or less typical capillary-like structures that subsequently form secondary branching vascular-like structures named "secondary sprouting". Such behavior is also characteristic for endothelial cells. This observations allow us to postulate the possibility of endothelial origin of FB sarcomas.