The Experimental Study On The Transplantation Of Human-derived Cells Into Animals

BackgroundBioartificial liver (BAL) and hepatocyte transplantation (HTx) confront a common problem: abundant source of high quality human-derived hepatocyte. The progress of the study on stem cells and human-derived hepatocyte cell line provides a new way to obtain human-derived hepatocyte.Bone marrow-derived stem cells are abundant in cell source, low-immunogenicity, can be obtained easily and from oneself, are ideal hepatic stem cell. Bone marrow-derived mesenchymal stem cell (MSCs) can differentiate into hepatocyte, nevertheless, it is difficult to obtain sufficient hepatocyte for clinic application by the differentiation of bone marrow-derived MSCs because the cultivation condition of bone marrow-derived MSCs is very strict in vitro so that they cannot repopulate and differentiate on a large scale. Generally, bone marrow-derived MSCs differentiate into hepatocyte in vitro. It is not reported to obtain human hepatocyte by the way of human hepatocytized of animal liver.Nowadays, there are many human hepatocyte cell line (hHCL) but only C3A hHCL are used in BAL. The other hHCL are not used in BAL. No hepatocyte cell lines are used in HTx mainly because of the problem of security. The oncogenicity of hHCL is an important aspect of security. CL-1 hHCL has good biological function while its oncogenicity should be discussed.Part I The experimental study on the transplantation on human-derived cells into the rat liverMaterials and MethodsThe human MSCs from bone marrow and human CL-1 cells(5 X104) were transplanted in to the liver of SD rats which 2-AAF+CCL4+CP rat models were set up. After transplantation, rats were maintained on a daily dose of CsA (3.5mg/kg). The hepatic function (ALT, TBiL) of the rats were checked, and then the human-derived cells of the transplanted rats were detected by Immunohistochemistry staining and PCR detection; lastly, the human-derived cells of the transplanted rats were detected by the real time RT-PCRResult and DiscussionThe liver function of the rats which had been transplanted human MSCs from bone marrow and human CL-1 cells were ameliorated but were not normal while those who had not been transplanted cells all die in a short time; the results of Immunohistochemistry staining and PCR detection indicate there were human-derived cells in the liver of the transplanted rats; the proportion of human hepatocyte in the rat which transplanted with human MSCs was 9.79% and 9.09% respectively and the proportion of human hepatocyte in the rat which transplanted with human MSCs was 9.27% and 8.86% respectively.ConclusionThe human MSCs from bone marrow and human CL-1 cells can survive in the liver of 2-AAF+CCL4+CP rat model; the human MSCs can diffenentiate to functional hepatocyte-like cells in the 2-AAF/CCLF4/CP ratmodel and replace 9.79%(14d) and 9.09% (28d) ; the CL-1 cells can replace 9.27%(14d) and8.86% (28d) ; the transplantation of the human MSCs and CL-1 cells can ameliorate the recovery of the 2-AAF+CCL4+CP rats; within 28 days, the CL-1 cells failed to formed planted tumor in the 2 -AAF+CCL4+CP rats.Part II The experimental study on the oncogenicity of human hepatocyte line CL-1 cells in nude miceMaterials and MethodsCL-1 cells(2X106) were cultured in vitro and transplanted into the subcutaneous tissue of nude mice The planted tumor, liver, lung and brain of the nude mice were removed for pathological examinationResultsThe planted tumor grew slowly initially while grew fast in the lastweek. 7/12 of the planted place formed planted tumor, the proportion ofoncogenicity is 58%. The planted tumors were round which diameter is( 8.26+ 1.49 ) mm. There are no planted tumors formed in the liver, lung andbrain.ConclusionThe CL-1 cells have a little oncogenicity in immunodeficiency mice.