乙醛脱氢酶1作为喉癌Hep-2细胞系肿瘤干细胞标志物的实验研究

Aldehyde dehydrogenase I can be used as a new marker of cancer stem cells in laryngeal cancer cells in vitro

目的探讨乙醛脱氢酶1（ALDH1）在人喉癌Hep-2细胞系中的表达，观察ALDH1高表达细胞的体外生长特性，确定喉癌Hep-2细胞系肿瘤干细胞标志物。方法采用荧光细胞化学染色和流式细胞术观察和检测喉癌Hep-2细胞系中的ALDH1的表达。采用流式分选术分离ALDHI高表达细胞，以四甲基偶氮唑蓝（MTT）法观察ALDH1不同亚群细胞的体外增殖能力，以流式细胞术检测ALDH1高表达细胞的体外分化能力。采用裸鼠成瘤实验比较不同亚群细胞的成瘤能力。结果喉癌Hep-2细胞系中ALDH1呈不同程度的表达，其中ALDHI高表达细胞占2．9％±0．6％。ALDH1高表达细胞的体外增殖能力高于ALDH1低表达和未分选细胞。在含血清的培养液中，经过6d培养，ALDH1高表达细胞由最初分选后的94．2％±3．8％下降至分选前水平。ALDH1高表达细胞的成瘤能力显著高于其他亚群。结论喉癌Hep-2细胞系中，ALDH1高表达细胞具有很强的体外分化能力、增殖能力和成瘤能力，可以作为Hep-2细胞系肿瘤干细胞的标志物之一。

Objective To detect the expression of aldehyde dehydrogenase 1 in human laryngeal cancer cells in vitro, and to explore whether it can be used as a marker of stem cells in human laryngeal cancer. Methods Fluorescence staining and flow cytometry were used to detect the expression of ALDHI in a human laryngeal cancer Hep-2 cell line, and fluorescence activated cells sorting was used to separate ALDH1^br cells. ALDH1 tumor ceils were cultured and their ability of proliferation and differentiation was observed in vitro. Results The expression of ALDH1 in Hep-2 ceils was different. The number of cells highly expressing ALDH1 was 2.9%± 0.6% . Compared with ALDH1^low ceils and unsorted cells, ALDH1^br cells exibited increased proliferation ability. In serum-containing RPM I1640 culture medium, the proportion of ALDH1^br cells was decreasing as days passed. The percentage of ALDH1^br ceils decreased from 94.2% ± 3.8% to the level before sorting. The ALDH1br cells demonstrated enhanced tumorigenic ability in nude mice. Conclusions In the laryngeal cancer Hep-2 cell line, the highly ALDH1-expressing cells show a strong ability of differentiation, proliferation and tumorigenesis. It indicates that ALDH1 can be used as a new marker of stem cells of laryngeal cancer ceils.