OBJECTIVETo study the biological characteristics of CD(44)(+) stem cells in human laryngeal carcinoma.

METHODSTumor samples were obtained from 5 patients, and then the human laryngeal carcinoma cells were cultured in vitro by primary tissue culture technique. Taking CD44 molecule as a marker to isolate CD(44)(+) subpopulation cells from laryngeal carcinoma cells for further study. CD(44)(+) and CD(44)(-) cells were cultured and observed fex their development. CD(44)(+) and CD(44)(-) cells were compared in their functional status (mRNA), cell cycles (G0/G1), their degree of differentiation (CK14 and Involucrin expression) and their morphologic character of the clone.

RESULTSThe percentages of CD(44)(+) cells were about 49.8% approximately 53.5% and the median was 51.3%. After culturing CD(44)(+) cells isolated from laryngeal carcinoma could proliferate and the percentage of CD(44)(+) remained the same. CD(44)(+) tumor cells contained much less RNA, more G0/G1 cells, expressed more CK14 protein and less Involucrin protein (less differentiated state). CD(44)(+) cells were multangular in shape with protuberances; CD(44)(-) cells showed a sharp and spindle feature. In comparison with CD(44)(-) cells, CD(44)(+) cells could create heterogeneous offspring by single cell culture of limiting dilution. By observing clone forming rate after single cell planting, it was found that the CD(44)(+) cells had stronger proliferation ability.

CONCLUSIONSCD(44)(+) cells possess some characteristics of stem cells, laryngeal carcinoma stem cells maybe exist in CD(44)(+) cells.