RESUMEN
AIM:To isolate and culture tumor stem cells in human retinoblastomas (RTSC). METHODS: Retinoblastoma (RB) single cells acquired from fresh tumors of RB patients by enzyme digestion were seeded in serum-free medium at a density of 1?10~8 cells/L. Clonal cultures were plated at a density of 1?10~6 cells/L. Secondary tumor spheres were triturated again and passaged in fresh medium. The sphere-forming, proliferation and differentiation assays were performed. RT-PCR and immunocytochemistry were performed to identify the RTSC and differentiated cells. RESULTS: All RB tumors studied produced proliferating neurosphere-like tumor spheres, which were also passaged multiple times. These tumor spheres had the capability to self-renew, proliferate in SFM medium, expressed retinal progenitor cell related genes, and differentiated into neurons and glia when they were transferred to differentiation conditions.CONCLUSION:Our findings demonstrated that there were subsets of tumor stem cells resembling retinal progenitor cells in human RB, which can be isolated, cultured in SFM. The RTSC may be original cells of RB tumor, and also become the new target of tumor therapy.