The Primary Research Of Esophageal Carcinoma Tumor Stem Cells

Objectives:Established a method to enrich the esophageal carcinoma stemcells via in serum-free medium and identified its biologicalcharacteristics and if them have radiation resistance.Methods:The human esophageal carcinoma OE-19were cultured in adherentand suspension culture methods.The expression of CD44was measured by flowcytometry.We observed their growing character in RPMI-1640medium,capability of clone in soft agar and the radiation resistance oftwo kinds cells.Results:Successfully cultured mammospheres which enriched the stem cellphenotype of CD44in serum-free medium.The expression of CD44insuspension culture was62.46%,while in adherent culture the expressionwas only11.74%.The growth curve displayed that suspension cells has thestronger proliferative capacity than the adherent cells and thesuspension cells showed stronger ability of forming clonies in soft agarassay comparing with the adherent cell. The suspended cells and adherentgrowing cells was irradiated by5Gy,10Gy,15Gy, the former cells ofCD44+demonstrated two groups that are the strongly positive and weaklypositive cells,the proportion of CD44in strong positive cells weregradually decreased,they are respectively77.8%,66.5%,57.53%, theproportion of CD44in weakly positive cells were gradually increased, theyare respectively21.65%,31.57%,41.38%, while the latter CD44positivecells decreases with the increase of radiation dose, they are respectively18.93%,14.05%,9.95%.But when the irradiation dose increased to30Gy,the survival of the suspended cells and adherent cells was significantlyreduced, and the viable cells were not detected CD44+cells.Conclusion:The mammosphere had the properties of cancer stem-like cells,which possessed the ability of self-renewal.Furthermore,it hadstronger ability of proliferation,forming clonies and radiationresistance. The mammosphere enriched the esophageal carcinoma stem cellsand CD44may be the marker of esophageal carcinoma stem cells.