Tumorigenicity Of Human Fetal Brain-derived Neural Precursor Cells

ObjectiveTo study the tumorigenicity of the human fetal brain-derived neural precursor cellspreliminarily in animal and clinical levels, by two methods of nude mice tumorigenicexperimental and clinical follow-up head MRI scan, to provide technical support for thesafety of clinical transplantation of neural precursor cells.MethodsTo select human embryonic brain tissue of10~14weeks of gestation voluntary abortedwhich will be the source of human fetal brain-derived neural precursor cells. To culture thehuman fetal brain-derived neural precursor cells in vitro to the first generation,the25thgenerations,the40th generation,the60th generations,and each generation of cells wereprepared into single cell suspensions and neurospheres to detect tumor by nude micesubcutaneous and to take293T cells as a positive control group. The experiment, a total ofnine groups, each group5only4~8weeks of BALB/C nude mice (purchased from thepeople’s liberation army military academy of medical sciences laboratory animal center),1x107cells per only nude mice subcutaneously. The nude mice will be raised six monthsafter cell inoculation. To observe the mental state of nude mice, the overall appearance,every day diets, defecation and the inoculation of local presence of abnormal situation suchas nodules or masses, mice were euthanized at six months after inoculation, the inoculationof local skin, subcutaneous tissue and liver, spleen, heart and kidney of histopathologicsections and HE staining, and pathologists read please, observe whether tumor formated. In October,2007-December2011, the navy general hospital pediatric out of about520cases of children with brain transplantation of neural precursor cells, to extract80cases ofchildren with follow-up head MRI scan using random indicator method to randomsampling, the head MRI scan inspection time from neural precursor cells transplantationtherapy for2years, all head MRI scan results are read by medical imaging experts toobserve whether brain tumor formated.ResultsSpirit and eating of nude mice in positive control group293t cells inoculated have noobvious abnormalities. After20days the vaccination site can reach the quality, and thetoughening of small nodules, and the volume of a nodule increases gradually, After60days5only nude mice inoculated both local obvious bump, qualitative hard, poor mobility,round,1.52.5cm in diam.180days will be nude mice death, anatomical remove lump,confirmed by pathological section and HE staining mass was indeed tumor. Groups of nudemice inoculated hNSCs all can live to more than90days, after90days each group nudemice in addition to have1~2die, have more than3only live to180days. The specificcause of death is unknown, presumably, infection more likely. Nude mice died a few daysbefore death appear listlessness, eating less. Spirit, diet and shit character of the othergroups of nude mice had no obvious abnormalities. Groups of nude mice after neuralprecursor cells inoculated local have not seen mass or nodule formation. Back in time, todie in the process of rearing nude mice to death, live to180days of nude mice to anatomyof illness and death of nude mice, local organization and take out the inoculation of fixed,liver, spleen, heart, kidney and histopathologic sections and HE staining, pathologists readnot found after a tumor formation. To checks head MRI scan of80patients random sampled in our department receivetransplanted neural progenitor cells. Medical imaging experts read head MRI scan andfound no tumor formation.ConclusionNo tumor formated in the nude mice experiments after the subcutaneous injection ofdifferent algebraic human fetal brain-derived neural precursor cells neurospheres and singlecell suspension. Cranial MRI scan of80patients random sampled who underwent neuralprecursor cells transplantation found no tumor formation. It preliminary confirmed thathuman fetal brain-derived neural precursor cells cultured by our lab did not undergomalignant transformation, no tumorigenicity, support its transplantation therapy for clinicalsafety. But this experiment in each group of cells with5only nude mice, a larger samplesize is needed to more fully prove that human fetal-brain derived neural precursor cellscultured in vitro no tumor formated in nude mice. Don’t tell that human fetal-brain derivedneural precursor cells for clinical cell transplantation therapy is absolutely safe, large-scaleclinical trials are still need to continue to study and explore.