Transdifferentiation of human MNNG/HOS osteosarcoma cells into vascular endothelial cells in vitro and in vivo.

Abstract

The transdifferentiation of cancer cells into other types of cells in several types of tissues or organs has been studied. However, whether human osteosarcoma MNNG/HOS cells can transdifferentiate into other types of cells has seldom been reported. Meanwhile, the mechanism of tumor angiogenesis is still disputed, and whether MNNG/HOS cells participate in angiogenesis in osteosarcoma remains unknown. In the present study, the investigation was divided into two parts: invitro and invivo. Invitro, we cultivated MNNG/HOS cells under hypoxic conditions for 4days and found that they typically showed a characteristic 'flagstone' appearance as cultured vascular endothelial cells (VECs). MNNG/HOS cells that were cultivated on Matrigel under hypoxic conditions gradually formed tubular-like structures. Furthermore, when cultured under hypoxic conditions for 4days, MNNG/HOS cells also transcribed and expressed several molecular markers of VECs (CD31, CD34 and vWF). Invivo, MNNG/HOS cells (1x106cells) were cultivated under hypoxic conditions and subcutaneously injected into nude mice; the mice were sacrificed 49days after inoculation. Immunohistochemical staining with anti-human CD31 antibody showed evidence of tumor angiogenesis in human osteosarcoma MNNG/HOS cells. The results demonstrated that MNNG/HOS cells can transdifferentiate into vascular endothelial cell-like cells invitro and invivo.