RESUMO
Objective To observe the expression of tumor stem cell markers P 75NTR,Oct-4,Sox-2,Lin28 and Nanog in the tumor sphere from esophageal squamous cells carcinoma Eca 109 and identify the esophageal squamous cell cancer stem cell marker .Methods The serum-free culture method was used for generating tumor spheres: proliferation was observed in enrichment culture tumor spheres .Small tumor spheres were obtained after 5 days culture and big and round tumor spheres appeared after 14 days culture which were collected for experiments and passaged .The expression and location of P75NTR,Oct-4,Sox-2,Lin28, and Nanog were detected by immunofluorescence cytochemistry .Results The expressions of P75NTR,Oct-4 and Lin28 were positive in the center of tumor spheres and some on cytoplasm and other in nuclei of Eca109 monolayer cells.However, Oct-4 fluorescence intensity was weaker than P75NTR.The expressions of Sox-2 and Nanog were positive in cytoplasm of tumor spheres and Eca 109 monolayer cells .Conclusion The cells expressing P75NTR, Oct-4, and Lin28 in the center of the tumor sphere may be esophageal cancer stem cells .