Preliminary Study Of Isolation And Identification Of Cancer Stem Cells From Human Esophageal Carcinoma

Objects:To isolate and identify cancer stem cells from ECCs using p75NTR cell surface marker. Methods: ECCs were preminirily cultured from surgically resected specimens and cell lines were established. Using MACS method isolated p75NTR positive cells from ECCs. In vitro p75NTR positive cells culture was employed to observe their growing character in DMEM medium and capability of clone in soft agar. It was obsered p75NTR positive cells cultured in SFM to form tumor cell spheres. To determine the ability of tumorigenisis of p75NTR positive cells, they were injected into Balb/c nude mice subcutaneously. The proportions of p75NTR positive cells was detected after culturing in SFM. ECCs were cultured in DMEM with chemotherapy drugs to detect the change of proportions of p75NTR positive cells. Results: Six cell lines were established from human esophageal carcinoma successfully. Using flow cytometry, 0~3.35% of p75NTR positive cells were detected in ECCs. The purity of p75NTR positive cells isolated by MACS was up to 90%, the recovery about 20%. The p75NTR positive cells showed stronger ability of forming clonies in soft agar assay comparing with p75NTR negative cells; in addition, they could grow and form cell spheres in SFM. It was demonstrated by the ability of as few as 2000 p75NTR positive cells to give rise to tumors in xenotransplantation. ECCs can form cell spheres cultured in SFM and the proportion of p75NTR positive cells raised in cell spheres. Cultured in DMEM with chemotherapy drugs, the higher proportion of p75NTR positive cells was detected in ECCs . The survival ratio of p75NTR posotive cells showed markedly higher than autologous p75NTR negative cells as exposed to chemotherapertic agents. Conclutions: The p75NTR positive cells had the properties of cancer stem cells, which possesd the ability of self-renew, differentiation and proliferation; furthermore, they had stronger ability of forming clonies and tumorigenic in xenotransplantation and showed drug resistance to chemotherapy drugs.