[Preliminary study on biological characteristics of CD(44)(+) stem cells in human laryngeal carcinoma].

Objective To study the biological characteristics of CD44＋ stem cells in human laryngeal carcinoma. Methods Tumor 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 CD44＋ subpopulation cells from laryngeal carcinoma cells for further study. CD44＋ and CD44- cells were cultured and observed fex their development. CD44＋ and CD44-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. Results The percentages of CD44＋ ceils were about49. 8% - 53.5% and the median was 51.3%. After culturing CD44＋ cells isolated from laryngeal carcinoma could proliferate and the percentage of CD44＋ remained the same. CD44＋tumor cells contained much less RNA, more GO/G1 cells, expressed more CK14 protein and less Involucrin protein （less differentiated state）. CD44＋ cells were multangular in shape with protuberances; CD44- cells showed a sharp and spindle feature. In comparison with CD44- cells, CD44＋ 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 CD44＋ cells had stronger proliferation ability. Conclusions CD44＋ cells possess some characteristics of stem cells, laryngeal carcinoma stem cells maybe exist in CD44＋ cells. Key words: Tumor cells, cultured; Tumor stem cells; Laryngeal neoplasms; Carcinoma, squamous cell