Preliminary Research On Tumor Heterogeneity Of Cell Fusion By Establishment Of Nude Mouse Choroid Plexus Transplantation Tumor Model

Objective:Cell heterogeneity is a recognized characteristic of malignant tumors,but there is a dispute over the causes. Exploit the morphology of papillary cells of choroid plexus,specific marker protein(TTR)and the characteristics of fusioned tumor cells,To research the growth characteristics of the heterogeneity of tumor cell by the engraftment in choroid plexus in dual-color fluorescence nude mouse model.Methods: The glioma cells C6,GL621,SU3 expressing red fluorescent protein gene(RFP) and normal 92.1cells cultured in vitro were slowly and accurately injected into the lateral ventricle of GFP transgenic nude mice placed in a stereotaxic apparatus under the control of micro pump. Finally brains of tumor-bearing mice were removed completely and frozen immediately then sectioned into 5um thick serial slices.The growth of glioma cells genraftment in choroid plexus was observed under Light microscope and fluorescence microscopic.Results:The tumorigenicity rate was 40/40(100%) in all of the inoculated nude mice. Tumor cells planted in the both sides of thechoroid plexus in every tumor-bearing mouse and later to the surrounding proliferation, invasion of the brain parenchyma and ventricular wall. Melanoma cells are also widely spread in the subarachnoid space. According to the high expression TTR of choroid plexus epithelial cells, high expression Nestin of tumor cells or melanin, we can find two kinds relevant cells by immunohistochemical staining,results that fusion reaction was occurred between tumor cells and choroid plexus cells.Conclusions: Establishment of nude mouse choroid plexus transplantation tumor model,different types of tumor cells were determined in the choroid plexus. In the same cell, the parental characteristics of the transplanted tumor cells and choroid plexus were retained.Both demonstrate that transplantation the heterogeneity of tumor cells from human andmouse species differences and tumor cell type of limiting, and show that tumor heterogeneity can be derived from the cell fusion.